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Bernstein LR, Mackenzie ACL, Durkin K, Kraemer DC, Chaffin CL, Merchenthaler I. Maternal age and gonadotrophin elevation cooperatively decrease viable ovulated oocytes and increase ootoxicity, chromosome-, and spindle-misalignments: '2-Hit' and 'FSH-OoToxicity' mechanisms as new reproductive aging hypotheses. Mol Hum Reprod 2023; 29:gaad030. [PMID: 37643633 DOI: 10.1093/molehr/gaad030] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/18/2023] [Indexed: 08/31/2023] Open
Abstract
While there is consensus that advanced maternal age (AMA) reduces oocyte yield and quality, the notion that high FSH reduces oocyte quality and causes aneuploidy remains controversial, perhaps due to difficulties controlling the confounding variables of age and FSH levels. Here, contributions of age and gonadotrophin elevation were separately controlled using a mouse model of human female reproductive aging. Ovulated oocytes were collected from young and midlife mice after 0-, 2.6-, or 17-day treatment with the FSH analog equine chorionic gonadotrophin (eCG), to model both exogenous FSH elevation within a single treatment cycle (as in controlled ovarian stimulation (COS)), and chronic endogenous FSH elevation during multiple cycles (as in diminished ovarian reserve). After 17-day eCG, fewer total oocytes/mouse are ovulated in midlife than young mice, and a precipitous decline in viable oocytes/mouse is observed in midlife but not young mice throughout eCG treatment. eCG is potently ootoxic to ovulatory oocytes and strongly induces chromosome- and spindle-misalignments within 2.6 days of eCG in midlife, but only after 17 days in young mice. These data indicate that AMA increases susceptibility to multiple adverse effects of elevated FSH activity in ovulated oocytes, including declines in total and viable oocytes/mouse, and induction of ootoxicity and aneuploidy. Two hypotheses are proposed for underlying causes of infertility in women. The FSH OOToxicity Hypothesis ('FOOT Hypothesis') posits that high FSH is ootoxic to ovulatory oocytes and that FSH ootoxicity is a root cause of low pregnancy success rates in naturally cycling women with high FSH and IUI patients undergoing COS. The '2-Hit Hypothesis' posits that AMA increases susceptibility to FSH-induced ootoxicity and aneuploidy.
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Affiliation(s)
- Lori R Bernstein
- Pregmama LLC, Gaithersburg, MD, USA
- Department of Cell Biology and Genetics, Texas A & M School of Medicine, College Station, TX, USA
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Veterinary Integrative Biosciences, Texas A&M School of Veterinary Medicine, College Station, TX, USA
| | - Amelia C L Mackenzie
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Keith Durkin
- Department of Veterinary Integrative Biosciences, Texas A&M School of Veterinary Medicine, College Station, TX, USA
| | - Duane C Kraemer
- Department of Veterinary Physiology and Pharmacology, Texas A & M College of Veterinary Medicine, College Station, TX, USA
| | - Charles L Chaffin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Istvan Merchenthaler
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
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Vaiarelli A, Cimadomo D, Scarafia C, Innocenti F, Amendola MG, Fabozzi G, Casarini L, Conforti A, Alviggi C, Gennarelli G, Benedetto C, Guido M, Borini A, Rienzi L, Ubaldi FM. Metaphase-II oocyte competence is unlinked to the gonadotrophins used for ovarian stimulation: a matched case-control study in women of advanced maternal age. J Assist Reprod Genet 2023; 40:169-177. [PMID: 36586005 PMCID: PMC9840736 DOI: 10.1007/s10815-022-02684-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 12/04/2022] [Indexed: 01/01/2023] Open
Abstract
PURPOSE An impact of different gonadotrophins selection for ovarian stimulation (OS) on oocyte competence has yet to be defined. In this study, we asked whether an association exists between OS protocol and euploid blastocyst rate (EBR) per metaphase-II (MII) oocytes. METHODS Cycles of first preimplantation genetic testing for aneuploidies conducted by women ≥ 35 years old with their own metaphase-II oocytes inseminated in the absence of severe male factor (years 2014-2018) were clustered based on whether recombinant FSH (rec-FSH) or human menopausal gonadotrophin (HMG) was used for OS, then matched for the number of fresh inseminated eggs. Four groups were outlined: rec-FSH (N = 57), rec-FSH plus rec-LH (N = 55), rec-FSH plus HMG (N = 112), and HMG-only (N = 127). Intracytoplasmic sperm injection, continuous blastocyst culture, comprehensive chromosome testing to assess full-chromosome non-mosaic aneuploidies and vitrified-warmed euploid single embryo transfers (SETs) were performed. The primary outcome was the EBR per cohort of MII oocytes. The secondary outcome was the live birth rate (LBR) per first SETs. RESULTS Rec-FSH protocol was shorter and characterized by lower total gonadotrophin (Gn) dose. The linear regression model adjusted for maternal age showed no association between the Gn adopted for OS and EBR per cohort of MII oocytes. Similarly, no association was reported with the LBR per first SETs, even when adjusting for blastocyst quality and day of full blastulation. CONCLUSION In view of enhanced personalization in OS, clinicians shall focus on different endpoints or quantitative effects related to Gn action towards follicle recruitment, development, and atresia. Here, LH and/or hCG was administered exclusively to women with expected sub/poor response; therefore, we cannot exclude that specific Gn formulations may impact patient prognosis in other populations.
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Affiliation(s)
- Alberto Vaiarelli
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy.
| | - Danilo Cimadomo
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy
| | - Carlotta Scarafia
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy
| | - Federica Innocenti
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy
| | | | - Gemma Fabozzi
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy
| | - Livio Casarini
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Center for Genomic Research, University of Modena and Reggio Emilia, Modena, Italy
| | - Alessandro Conforti
- Department of Neuroscience, Reproductive Science and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Carlo Alviggi
- Department of Neuroscience, Reproductive Science and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Gianluca Gennarelli
- Obstetrics and Gynecology 1U, Physiology of Reproduction and IVF Unit, Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Turin, Italy
- Livet, GeneraLife IVF, Turin, Italy
| | - Chiara Benedetto
- Obstetrics and Gynecology 1U, Physiology of Reproduction and IVF Unit, Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Turin, Italy
| | - Maurizio Guido
- Department of Clinical Medicine, Public Health, Life Sciences and Environment (MeSVA), University of L'Aquila, L'Aquila, Italy
| | | | - Laura Rienzi
- Clinica Valle Giulia, GeneraLife IVF, Via G. de Notaris 2B, 00197, Rome, Italy
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
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Magaton IM, Helmer A, Eisenhut M, Roumet M, Stute P, von Wolff M. Oocyte maturity, oocyte fertilization and cleavage-stage embryo morphology are better in natural compared with high-dose gonadotrophin stimulated IVF cycles. Reprod Biomed Online 2022; 46:705-712. [PMID: 36754739 DOI: 10.1016/j.rbmo.2022.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/21/2022]
Abstract
RESEARCH QUESTION Does high-dose gonadotrophin stimulation have an effect on oocyte and early-stage embryo development? DESIGN This was a retrospective study including 616 natural cycle IVF (NC-IVF) and 167 conventional IVF (cIVF) cycles. In total, 2110 oocytes were retrieved and analysed in fresh cycles. In NC-IVF, only human chorionic gonadotrophin was applied to trigger ovulation. In cIVF, antagonist protocols with daily 150-300 IU of human menopausal gonadotrophins were performed. The effect of gonadotrophins on oocyte and early-stage embryo development was analysed. Primary outcomes were the occurrence of mature (metaphase II) oocytes, zygotes and embryos with good morphology at the cleavage stage 2 days after oocyte retrieval. RESULTS The mature oocyte rate (number of mature oocytes/number of retrieved oocytes) was higher in NC-IVF than cIVF cycles (89% versus 82%, adjusted odds ratio [aOR] 1.79, P = 0.001), as was the zygote rate per oocyte retrieved (70% versus 58%, aOR 1.76, P = 0.001) and the zygote rate per mature oocyte (79% versus 71%, aOR 1.62, P = 0.001). The percentage of zygotes that developed into cleavage-stage embryos was no different. For the transferred embryos, the probability of having a good embryo morphology with four blastomeres and a fragmentation of <10% (score 0) in cleavage-stage embryos was found to be higher in NC-IVF (proportional aOR for four blastomeres 2.00, P < 0.001; aOR 1.87 for a fragmentation score of 0, P = 0.003). CONCLUSIONS Oocyte maturity, oocyte fertilization and morphology of the cleavage-stage embryo are affected by high-dose gonadotrophin stimulation in fresh IVF cycles.
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Affiliation(s)
- Isotta M Magaton
- Division of Gynaecological Endocrinology and Reproductive Medicine, University Women's Hospital, Inselspital, Bern, Switzerland.
| | - Anja Helmer
- Division of Gynaecological Endocrinology and Reproductive Medicine, University Women's Hospital, Inselspital, Bern, Switzerland
| | - Markus Eisenhut
- Division of Gynaecological Endocrinology and Reproductive Medicine, University Women's Hospital, Inselspital, Bern, Switzerland
| | - Marie Roumet
- Clinical Trials Unit Bern, University of Bern, Switzerland
| | - Petra Stute
- Division of Gynaecological Endocrinology and Reproductive Medicine, University Women's Hospital, Inselspital, Bern, Switzerland
| | - Michael von Wolff
- Division of Gynaecological Endocrinology and Reproductive Medicine, University Women's Hospital, Inselspital, Bern, Switzerland
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Yun Y, Lee S, So C, Manhas R, Kim C, Wibowo T, Hori M, Hunter N. Oocyte Development and Quality in Young and Old Mice following Exposure to Atrazine. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:117007. [PMID: 36367780 PMCID: PMC9651182 DOI: 10.1289/ehp11343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 10/10/2022] [Accepted: 10/17/2022] [Indexed: 06/01/2023]
Abstract
BACKGROUND Egg development has unique features that render it vulnerable to environmental perturbation. The herbicide atrazine is an endocrine disruptor shown to have detrimental effects on reproduction across several vertebrate species. OBJECTIVES This study was designed to determine whether exposure to low levels of atrazine impairs meiosis in female mammals, using a mouse model; in particular, the study's researchers sought to determine whether and how the fidelity of oocyte chromosome segregation may be affected and whether aging-related aneuploidy is exacerbated. METHODS Female C57BL/6J mice were exposed to two levels of atrazine in drinking water: The higher level equaled aqueous saturation, and the lower level corresponded to detected environmental contamination. To model developmental exposure, atrazine was ingested by pregnant females at 0.5 d post coitum and continued until pups were weaned at 21 d postpartum. For adult exposure, 2-month-old females ingested atrazine for 3 months. Following exposure, various indicators of oocyte development and quality were determined, including: a) chromosome synapsis and crossing over in fetal oocytes using immunofluorescence staining of prophase-I chromosome preparations; b) sizes of follicle pools in sectioned ovaries; c) efficiencies of in vitro fertilization and early embryogenesis; d) chromosome alignment and segregation in cultured oocytes; e) chromosomal errors in metaphase-I and -II (MI and MII) preparations; and f) sister-chromatid cohesion via immunofluorescence intensity of cohesin subunit REC8 on MI-chromosome preparations, and measurement of interkinetochore distances in MII preparations. RESULTS Mice exposed to atrazine during development showed slightly higher levels of defects in chromosome synapsis, but sizes of initial follicle pools were indistinguishable from controls. However, although more eggs were ovulated, oocyte quality was lower. At the chromosome level, frequencies of spindle misalignment and numerical and structural abnormalities were greater at both meiotic divisions. In vitro fertilization was less efficient, and there were more apoptotic cells in blastocysts derived from eggs of atrazine-exposed females. Similar levels of chromosomal defects were seen in oocytes following both developmental and adult exposure regimens, suggesting quiescent primordial follicles may be a consequential target of atrazine. An important finding was that defects were observed long after exposure was terminated. Moreover, chromosomally abnormal eggs were very frequent in older mice, implying that atrazine exposure during development exacerbates effects of maternal aging on oocyte quality. Indeed, analogous to the effects of maternal age, weaker cohesion between sister chromatids was observed in oocytes from atrazine-exposed animals. CONCLUSION Low-level atrazine exposure caused persistent changes to the female mammalian germline in mice, with potential consequences for reproductive lifespan and congenital disease. https://doi.org/10.1289/EHP11343.
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Affiliation(s)
- Yan Yun
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
- Howard Hughes Medical Institute, University of California, Davis, Davis, California, USA
| | - Sunkyung Lee
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Christina So
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Rushali Manhas
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Carol Kim
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Tabitha Wibowo
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Michael Hori
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
| | - Neil Hunter
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, California, USA
- Howard Hughes Medical Institute, University of California, Davis, Davis, California, USA
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
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Liu X, Mai H, Chen P, Zhang Z, Wu T, Chen J, Sun P, Zhou C, Liang X, Huang R. Comparative analyses in transcriptome of human granulosa cells and follicular fluid micro-environment between poor ovarian responders with conventional controlled ovarian or mild ovarian stimulations. Reprod Biol Endocrinol 2022; 20:54. [PMID: 35313911 PMCID: PMC8935846 DOI: 10.1186/s12958-022-00926-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/07/2022] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Both mild and conventional controlled ovarian stimulation are the frequently used protocols for poor ovarian responders. However, there are some debates about which treatment is better. Moreover, little is known about the follicular physiology after the two ovarian stimulation protocols. This study was intended to investigate the features in granulosa cells and follicular fluid micro-environment after the two different ovarian stimulation protocols in poor responders. METHODS Granulosa cells RNA were sequenced using Illumina Hiseq technology. Specific differently expressed genes and proteins were verified by real-time quantitative PCR and Western blot analysis. Moreover, hormone and cytokine concentrations in the follicular fluid were measured by electrochemiluminescence immunoassay and enzyme-linked immunoabsorbent assay. The correlation between the results of molecular experiments and the laboratory outcomes were analyzed by Spearman correlation analysis. RESULTS The differentially expressed genes between the two groups were involved in 4 signaling pathways related to the follicular development; three proteins pertinent to the TGF-β signaling pathway were expressed differently in granulosa cells between the two, and the constituents in the follicular fluid were also different. Further, a correlation between the TGF-β signaling pathway and the good-quality embryo was observed. CONCLUSIONS The present study made a comparison for the first time in the transcriptome of human granulosa cells and the follicular fluid micro-environment between poor responders with the conventional controlled ovarian stimulation or the mild ovarian stimulation, showing that the TGF-β signaling pathway may correlate with the good-quality of embryos in the mild group, which may be instrumental to the choice of optimal management for IVF patients.
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Affiliation(s)
- Xiaoping Liu
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Huisi Mai
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Panyu Chen
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Zhiqiang Zhang
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Taibao Wu
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Jianhui Chen
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Peng Sun
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Chuanchuan Zhou
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Xiaoyan Liang
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Rui Huang
- Reproductive Medicine Research Center, the Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
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Zhang T, Zhou Y, Li L, Zhao Y, De Felici M, Reiter RJ, Shen W. Melatonin protects prepuberal testis from deleterious effects of bisphenol A or diethylhexyl phthalate by preserving H3K9 methylation. J Pineal Res 2018; 65:e12497. [PMID: 29655234 DOI: 10.1111/jpi.12497] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/30/2018] [Indexed: 12/13/2022]
Abstract
A growing number of couples experience fertility issues with almost half being due to malefactors. The exposure to toxic environmental contaminants, such as endocrine disruptors (EDs), has been shown to negatively affect male fertility. EDs are present in the environment, and exposure to these toxins results in the failure of spermatogenesis. The deleterious effects of EDs on spermatogenesis have been well documented, whereas improvement of infertility associated with spermatogenesis defects remains a great challenge. Herein, we report that in vitro exposure of prepuberal mouse testes to two well-known endocrine disruptors (EDs), bisphenol A (BPA) or diethylhexyl phthalate (DEHP), impairs spermatogenesis with perturbing self-renewal, spermatogonia activity, and meiosis. Evidence indicates that such effects are likely due, at least in part, to decreased G9a-dependent H3K9 di-methylation. Of note, we found that melatonin (MLT) protected the testis from the negative ED impacts with preserving spermatogonia stem and meiotic cells, along with maintaining normal H3K9 di-methylation in these cells. Taken together, this work documents that BPA and EDHP adversely affect prepuberal spermatogenesis and perturb crucial epigenetic activities in male germ cells and highlight the protective ability of MLT.
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Affiliation(s)
- Teng Zhang
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Yang Zhou
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Stem Cells and Reproductive Biology, Institute of Zoology, Chinese Academy of Science, Beijing, China
| | - Lan Li
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Yong Zhao
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
| | - Massimo De Felici
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health, San Antonio, TX, USA
| | - Wei Shen
- College of Life Sciences, Institute of Reproductive Sciences, Qingdao Agricultural University, Qingdao, China
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Ochin H, Ma X, Wang L, Li X, Song J, Meng Y, Shen J, Cui YG, Liu J. Low dose clomiphene citrate as a mild stimulation protocol in women with unsuspected poor in vitro fertilization result can generate more oocytes with optimal cumulative pregnancy rate. J Ovarian Res 2018; 11:37. [PMID: 29728130 PMCID: PMC5934891 DOI: 10.1186/s13048-018-0408-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/20/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The use of long protocol during controlled ovarian stimulation for assisted reproduction attracts high dosage of gonadotropins. High dose of gonadotropins can be detrimental to oocyte development, which affects its quality and compromises the treatment outcome. Mild stimulation protocols that attract low dose gonadotropins could be useful alternative regimen to address such problems. This study evaluated the efficacy of low dose clomiphene citrate based protocol plus low dose gonadotropins on predicted normal responder patients who had unsuspected poor in vitro fertilization (IVF) result, following an initial stimulation with long gonadotropin-releasing hormone (GnRH) agonist protocol. METHODS This a retrospective study of 65 infertile women who underwent 130 cycles in our center from January 2011 to December 2014. The initial IVF cycle (Group 1) was treated with long GnRH-a protocol plus a high dose of gonadotropins (≥150 IU/d), while second IVF cycle (Group 2) had low dose clomiphene citrate based protocol plus low dose gonadotropins (75-112.5 IU/d). RESULTS The rate of cumulative pregnancy/started cycle (9.2% [6/65] vs. 51% [33/65]; P < 0001) was significantly better in CC protocol than the long GnRH agonist protocol. The number of oocytes retrieved was also higher in CC protocol compared to the long protocol (7.26 ± 1.95 vs. 5.98 ± 1.31; P = 0.03). There was a lower number of patients without embryos (12.31% vs. 33.85%; p < 0.0001) in CC protocol than long protocol. CONCLUSIONS This study showed a better cumulative pregnancy rate in the low dose CC based protocol. There was a higher number of oocytes retrieved after using a lower total dose of recombinant FSH in CC protocol. Thus, clomiphene treatment plus low dose rFSH can be an alternative option for such patients in second cycle stimulation instead of repeating long protocol regimen. Randomized controlled studies with larger number of patients will be needed for more accurate evidence.
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Affiliation(s)
- Humphrey Ochin
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Xiang Ma
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Lin Wang
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Xuan Li
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Jie Song
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Yan Meng
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Jiandong Shen
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Yu-Gui Cui
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China
| | - Jiayin Liu
- Clinical Center for Reproductive Medicine, 300 Guangzhou Road. First Affiliated Hospital of Nanjing Medical University, 210029, The State Key Laboratory of Reproductive Medicine., Nanjing, People's Republic of China.
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8
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Narkwichean A, Maalouf W, Baumgarten M, Polanski L, Raine-Fenning N, Campbell B, Jayaprakasan K. Efficacy of Dehydroepiandrosterone (DHEA) to overcome the effect of ovarian ageing (DITTO): A proof of principle double blinded randomized placebo controlled trial. Eur J Obstet Gynecol Reprod Biol 2017; 218:39-48. [PMID: 28934714 DOI: 10.1016/j.ejogrb.2017.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 09/03/2017] [Accepted: 09/08/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To evaluate the effect of DHEA supplementation on In-Vitro Fertilisation (IVF) outcome as assessed by ovarian response, oocyte developmental competence and live birth rates in women predicted to have poor ovarian reserve (OR). The feasibility of conducting a large trial is also assessed by evaluating the recruitment rates and compliance of the recruited participants with DHEA/placebo intake and follow-up rates. STUDY DESIGN A single centre, double blinded, placebo controlled, randomized trial was performed over two years with 60 women undergoing in-vitro fertilisation (IVF). Subjects were randomized, based on a computer-generated pseudo-random code to receive either DHEA or placebo with both capsules having similar colour, size and appearance. 60 women with poor OR based on antral follicle count or anti-Mullerian hormone thresholds undergoing IVF were recruited. They were randomised to receive DHEA 75mg/day or placebo for at-least 12 weeks before starting ovarian stimulation. They had long protocol using hMG 300 IU/day. Data analysed by "intention to treat". Ovarian response, live birth rates and molecular markers of oocyte quality were compared between the study and control groups. RESULTS The recruitment rate was 39% (60/154). A total of 52 participants (27 versus 25 in the study and placebo groups) were included in the final analysis after excluding eight. While the mean (standard deviation) DHEA levels were similar at recruitment (9.4 (5) versus 7.5 (2.4) ng/ml; P=0.1), the DHEA levels at pre-stimulation were higher in the study group than in the controls (16.3 (5.8) versus 11.1 (4.5) ng/ml; P<0.01). The number (median, range) of oocytes retrieved (4, 0-18 versus 4, 0-15 respectively; P=0.54) and live birth rates (7/27, 26% versus 8/25, 32% respectively; RR (95% CI): 0.74 (0.22-2.48) and mRNA expression of developmental biomarkers in granulosa and cumulus cells were similar between the groups. CONCLUSION Pre-treatment DHEA supplementation, albeit statistical power in this study is low, did not improve the response to controlled ovarian hyperstimulation or oocyte quality or live birth rates during IVF treatment with long protocol in women predicted to have poor OR.
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Affiliation(s)
- Amarin Narkwichean
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom; Department of Obstetrics and Gynaecology, Faculty of Medicine, Srinakharinwirot University, Nakhon-Nayok, 26120, Thailand
| | - Walid Maalouf
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom
| | - Miriam Baumgarten
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom
| | - Lukasz Polanski
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom
| | - Nick Raine-Fenning
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom; NURTURE Fertility, Nottingham, NG10 5QG, United Kingdom
| | - Bruce Campbell
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom
| | - Kannamannadiar Jayaprakasan
- Division of Obstetrics and Gynaecology, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, Nottinghamshire, NG7 2UH, United Kingdom; Derby Fertility Unit, Royal Derby Hospital, Derby, DE22 3NE, United Kingdom.
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9
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Abstract
The impact of age on a woman's ability to produce normal eggs remains a great enigma of human biology. A new paper provides intriguing experimental evidence that age may cause a breakdown in the egg cell division machinery.
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Affiliation(s)
- Patricia Hunt
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, USA.
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10
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Bernstein LR, Mackenzie ACL, Lee SJ, Chaffin CL, Merchenthaler I. Activin Decoy Receptor ActRIIB:Fc Lowers FSH and Therapeutically Restores Oocyte Yield, Prevents Oocyte Chromosome Misalignments and Spindle Aberrations, and Increases Fertility in Midlife Female SAMP8 Mice. Endocrinology 2016; 157:1234-47. [PMID: 26713784 PMCID: PMC4769367 DOI: 10.1210/en.2015-1702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Women of advanced maternal age (AMA) (age ≥ 35) have increased rates of infertility, miscarriages, and trisomic pregnancies. Collectively these conditions are called "egg infertility." A root cause of egg infertility is increased rates of oocyte aneuploidy with age. AMA women often have elevated endogenous FSH. Female senescence-accelerated mouse-prone-8 (SAMP8) has increased rates of oocyte spindle aberrations, diminished fertility, and rising endogenous FSH with age. We hypothesize that elevated FSH during the oocyte's FSH-responsive growth period is a cause of abnormalities in the meiotic spindle. We report that eggs from SAMP8 mice treated with equine chorionic gonadotropin (eCG) for the period of oocyte growth have increased chromosome and spindle misalignments. Activin is a molecule that raises FSH, and ActRIIB:Fc is an activin decoy receptor that binds and sequesters activin. We report that ActRIIB:Fc treatment of midlife SAMP8 mice for the duration of oocyte growth lowers FSH, prevents egg chromosome and spindle misalignments, and increases litter sizes. AMA patients can also have poor responsiveness to FSH stimulation. We report that although eCG lowers yields of viable oocytes, ActRIIB:Fc increases yields of viable oocytes. ActRIIB:Fc and eCG cotreatment markedly reduces yields of viable oocytes. These data are consistent with the hypothesis that elevated FSH contributes to egg aneuploidy, declining fertility, and poor ovarian response and that ActRIIB:Fc can prevent egg aneuploidy, increase fertility, and improve ovarian response. Future studies will continue to examine whether ActRIIB:Fc works via FSH and/or other pathways and whether ActRIIB:Fc can prevent aneuploidy, increase fertility, and improve stimulation responsiveness in AMA women.
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Affiliation(s)
- Lori R Bernstein
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.), Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), and Anatomy and Neurobiology (I.M.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Molecular Biology and Genetics (S.-J.L.) and Gynecology and Obstetrics, Johns Hopkins University School of Medicine (L.R.B.), Baltimore, Maryland 21205; and Department of Veterinary Integrative Biosciences (L.R.B.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843
| | - Amelia C L Mackenzie
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.), Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), and Anatomy and Neurobiology (I.M.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Molecular Biology and Genetics (S.-J.L.) and Gynecology and Obstetrics, Johns Hopkins University School of Medicine (L.R.B.), Baltimore, Maryland 21205; and Department of Veterinary Integrative Biosciences (L.R.B.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843
| | - Se-Jin Lee
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.), Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), and Anatomy and Neurobiology (I.M.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Molecular Biology and Genetics (S.-J.L.) and Gynecology and Obstetrics, Johns Hopkins University School of Medicine (L.R.B.), Baltimore, Maryland 21205; and Department of Veterinary Integrative Biosciences (L.R.B.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843
| | - Charles L Chaffin
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.), Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), and Anatomy and Neurobiology (I.M.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Molecular Biology and Genetics (S.-J.L.) and Gynecology and Obstetrics, Johns Hopkins University School of Medicine (L.R.B.), Baltimore, Maryland 21205; and Department of Veterinary Integrative Biosciences (L.R.B.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843
| | - István Merchenthaler
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.), Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), and Anatomy and Neurobiology (I.M.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Departments of Molecular Biology and Genetics (S.-J.L.) and Gynecology and Obstetrics, Johns Hopkins University School of Medicine (L.R.B.), Baltimore, Maryland 21205; and Department of Veterinary Integrative Biosciences (L.R.B.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843
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11
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Fitzgerald AC, Peyton C, Dong J, Thomas P. Bisphenol A and Related Alkylphenols Exert Nongenomic Estrogenic Actions Through a G Protein-Coupled Estrogen Receptor 1 (Gper)/Epidermal Growth Factor Receptor (Egfr) Pathway to Inhibit Meiotic Maturation of Zebrafish Oocytes. Biol Reprod 2015; 93:135. [PMID: 26490843 DOI: 10.1095/biolreprod.115.132316] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/19/2015] [Indexed: 11/01/2022] Open
Abstract
Xenobiotic estrogens, such as bisphenol A (BPA), disrupt a wide variety of genomic estrogen actions, but their nongenomic estrogen actions remain poorly understood. We investigated nongenomic estrogenic effects of low concentrations of BPA and three related alkylphenols on the inhibition of zebrafish oocye maturation (OM) mediated through a G protein-coupled estrogen receptor 1 (Gper)-dependent epidermal growth factor receptor (Egfr) pathway. BPA (10-100 nM) treatment for 3 h mimicked the effects of estradiol-17beta (E2) and EGF, decreasing spontaneous maturation of defolliculated zebrafish oocytes, an effect not blocked by coincubation with actinomycin D, but blocked by coincubation with a Gper antibody. BPA displayed relatively high binding affinity (15.8% that of E2) for recombinant zebrafish Gper. The inhibitory effects of BPA were attenuated by inhibition of upstream regulators of Egfr, intracellular tyrosine kinase (Src) with PP2, and matrix metalloproteinase with ilomastat. Treatment with an inhibitor of Egfr transactivation, AG1478, and an inhibitor of the mitogen-activated protein kinase (MAPK) 3/1 pathway, U0126, increased spontaneous OM and blocked the inhibitory effects of BPA, E2, and the selective GPER agonist, G-1. Western blot analysis showed that BPA (10-200 nM) mimicked the stimulatory effects of E2 and EGF on Mapk3/1 phosphorylation. Tetrabromobisphenol A, 4-nonylphenol, and tetrachlorobisphenol A (5-100 nM) also inhibited OM, an effect blocked by cotreatment with AG1478, as well as with the GPER antagonist, G-15, and displayed similar binding affinities as BPA to zebrafish Gper. The results suggest that BPA and related alkylphenols disrupt zebrafish OM by a novel nongenomic estrogenic mechanism involving activation of the Gper/Egfr/Mapk3/1 pathway.
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Affiliation(s)
| | - Candace Peyton
- University of Texas at Austin Marine Science Institute, Port Aransas, Texas
| | - Jing Dong
- University of Texas at Austin Marine Science Institute, Port Aransas, Texas
| | - Peter Thomas
- University of Texas at Austin Marine Science Institute, Port Aransas, Texas
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12
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Shrestha D, La X, Feng HL. Comparison of different stimulation protocols used in in vitro fertilization: a review. ANNALS OF TRANSLATIONAL MEDICINE 2015. [PMID: 26207230 DOI: 10.3978/j.issn.2305-5839.2015.04.09] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Infertility is one of the major medical problems in the western world caused by genetic or epigenetic factors, or both, which has led to continuous research and advancements in the field of assisted reproductive technology (ART). Many stimulation protocols are available for controlled ovarian hyperstimulation (COH) in in vitro fertilization (IVF). This review compares the agonist long protocol, antagonist protocol and minimal stimulation protocol. Gonadotropin-releasing hormone (GnRH) antagonist and minimal stimulation protocol has shorter duration of treatment and less gonadotropin use. GnRH agonist long protocol is better in folliculogenesis and pregnancy rate, which is the imperative goal of COH. Despite its costly and lengthy approach, GnRH agonist long protocol has delivered satisfactory results in most women. On the other hand, patients with poor ovarian reserve may have greater advantage when considering minimal stimulation protocol. Evidently, it is crucial to have a larger scale studies with more focused comparisons, which take into account the differences in patients' response criteria and additional confounding variables (age, BMI, previous IVF outcomes etc.), in order to reach to a more definite conclusions.
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Affiliation(s)
- Deekshya Shrestha
- 1 Department of Reproduction, First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China ; 2 The New Fertility Center, New York Hospital Queens Affiliated Weill Medical College of Cornell University, New York, NY, USA
| | - Xiaolin La
- 1 Department of Reproduction, First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China ; 2 The New Fertility Center, New York Hospital Queens Affiliated Weill Medical College of Cornell University, New York, NY, USA
| | - Huai L Feng
- 1 Department of Reproduction, First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, China ; 2 The New Fertility Center, New York Hospital Queens Affiliated Weill Medical College of Cornell University, New York, NY, USA
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13
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Abstract
In contrast to current approaches, the aim of mild stimulation is to develop safer and more patient-friendly protocols in which the risks of the treatment as a whole are minimized. Mild stimulation is defined as the method when exogenous gonadotropins are administered at lower doses, and/or for a shorter duration in GnRH antagonist co-treated cycles, or when oral compounds (antiestrogens, aromatase inhibitors) are used for ovarian stimulation for IVF, with the aim of limiting the number of oocytes obtained to fewer than eight. In this chapter we discuss the relevant physiology of follicle development, the development of milder stimulation protocols, the implications of mild stimulation, the current state of affairs, and future developments.
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Affiliation(s)
- O Hamdine
- Department of Reproductive Medicine and Gynaecology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CS, Utrecht, The Netherlands
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14
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Impact of exogenous gonadotropin stimulation on circulatory and follicular fluid cytokine profiles. Int J Reprod Med 2014; 2014:218769. [PMID: 25763393 PMCID: PMC4334052 DOI: 10.1155/2014/218769] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 11/11/2014] [Indexed: 11/17/2022] Open
Abstract
Background. The natural cycle is the prototype to which we aspire to emulate in assisted reproduction techniques. Increasing evidence is emerging that controlled ovarian hyperstimulation (COH) with exogenous gonadotropins may be detrimental to oogenesis, embryo quality, and endometrial receptivity. This research aimed at assessing the impact of COH on the intrafollicular milieu by comparing follicular fluid (FF) cytokine profiles during stimulated in vitro fertilization (IVF) and modified natural cycle (MNC) IVF. Methods. Ten women undergoing COH IVF and 10 matched women undergoing MNC IVF were recruited for this pilot study. 40 FF cytokine concentrations from individual follicles and plasma were measured by fluid-phase multiplex immunoassay. Demographic/cycle/cytokine data were compared and correlations between cytokines were computed. Results. No significant differences were found between COH and MNC groups for patient and cycle demographics, including outcome. Overall mean FF cytokine levels were higher in the MNC group for 29/40 cytokines, significantly so for leukaemia inhibitory factor and stromal cell-derived factor-1α. Furthermore, FF MNC cytokine correlations were significantly stronger than for COH data. Conclusions. These findings suggest that COH perturbs intrafollicular cytokine networks, in terms of both cytokine levels and their interrelationships. This may impact oocyte maturation/fertilization and embryo developmental competence.
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15
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Stone BA, March CM, Ringler GE, Baek KJ, Marrs RP. Casting for determinants of blastocyst yield and of rates of implantation and of pregnancy after blastocyst transfers. Fertil Steril 2014; 102:1055-64. [DOI: 10.1016/j.fertnstert.2014.06.049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 10/24/2022]
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16
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Bisphenol A, oocyte maturation, implantation, and IVF outcome: review of animal and human data. Reprod Biomed Online 2014; 29:404-10. [PMID: 25154017 DOI: 10.1016/j.rbmo.2014.06.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/21/2014] [Accepted: 06/23/2014] [Indexed: 11/22/2022]
Abstract
Recent data have raised concerns about the detrimental effect of chronic exposure to environmental chemicals. Some chemicals affect the endocrine system (endocrine disruptors) and have been linked to several diseases, including infertility. One such endocrine disruptor is bisphenol A (BPA), a monomer widely used in the plastic industry, with nearly ubiquitous exposure. In this review, data on the effects of BPA on female fertility are summarized. Specifically, its effect is considered on folliculogenesis, oocyte maturation, embryo quality, and implantation, both in animal and human models. Animal studies have shown that BPA might impair prophase I, follicular growth, and implantation, and may be associated with spindle abnormalities. In humans, while in-vitro studies have suggested an association between BPA exposure and impaired oocyte meiosis, clinical evidence indicate possible adverse effects of BPA exposure on IVF outcomes. As human clinical data are still scarce, larger studies are required to further elucidate the effects of BPA exposure on female fertility.
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17
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Bernstein LR, Mackenzie ACL, Kraemer DC, Morley JE, Farr S, Chaffin CL, Merchenthaler I. Shortened estrous cycle length, increased FSH levels, FSH variance, oocyte spindle aberrations, and early declining fertility in aging senescence-accelerated mouse prone-8 (SAMP8) mice: concomitant characteristics of human midlife female reproductive aging. Endocrinology 2014; 155:2287-300. [PMID: 24654787 DOI: 10.1210/en.2013-2153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Women experience a series of specific transitions in their reproductive function with age. Shortening of the menstrual cycle begins in the mid to late 30s and is regarded as the first sign of reproductive aging. Other early changes include elevation and increased variance of serum FSH levels, increased incidences of oocyte spindle aberrations and aneuploidy, and declining fertility. The goal of this study was to investigate whether the mouse strain senescence-accelerated mouse-prone-8 (SAMP8) is a suitable model for the study of these midlife reproductive aging characteristics. Midlife SAMP8 mice aged 6.5-7.85 months (midlife SAMP8) exhibited shortened estrous cycles compared with SAMP8 mice aged 2-3 months (young SAMP8, P = .0040). Midlife SAMP8 mice had high FSH levels compared with young SAMP8 mice, and mice with a single day of high FSH exhibited statistically elevated FSH throughout the cycle, ranging from 1.8- to 3.6-fold elevation on the days of proestrus, estrus, metestrus, and diestrus (P < .05). Midlife SAMP8 mice displayed more variance in FSH than young SAMP8 mice (P = .01). Midlife SAMP8 ovulated fewer oocytes (P = .0155). SAMP8 oocytes stained with fluorescently labeled antitubulin antibodies and scored in fluorescence microscopy exhibited increased incidence of meiotic spindle aberrations with age, from 2/126 (1.59%) in young SAMP8 to 38/139 (27.3%) in midlife SAMP8 (17.2-fold increase, P < .0001). Finally, SAMP8 exhibited declining fertility from 8.9 pups/litter in young SAMP8 to 3.5 pups/litter in midlife SAMP8 mice (P < .0001). The age at which these changes occur is younger than for most mouse strains, and their simultaneous occurrence within a single strain has not been described previously. We propose that SAMP8 mice are a model of midlife human female reproductive aging.
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Affiliation(s)
- Lori R Bernstein
- Pregmama, LLC (L.R.B.), Gaithersburg, Maryland 20886; Departments of Epidemiology and Public Health (L.R.B., A.C.L.M., I.M.) and Obstetrics, Gynecology, and Reproductive Sciences (C.L.C.), University of Maryland School of Medicine, Baltimore, Maryland 21201; Department of Gynecology and Obstetrics (L.R.B.), Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; Departments of Veterinary Integrative Biosciences (L.R.B.) and Veterinary Physiology and Pharmacology (D.C.K.), Texas A&M College of Veterinary Medicine, College Station, Texas 77843; Divisions of Geriatric Medicine and Endocrinology (J.E.M., S.F.), St. Louis University School of Medicine, St. Louis, Missouri 63103; and St. Louis Veterans Affairs Medical Center (S.F.), St. Louis, Missouri 63106
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18
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19
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Navara KJ. The role of steroid hormones in the adjustment of primary sex ratio in birds: compiling the pieces of the puzzle. Integr Comp Biol 2013; 53:923-37. [PMID: 23900275 DOI: 10.1093/icb/ict083] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
There is ample evidence that birds have the ability to adjust their offsprings' sex ratios before fertilization occurs. Recent work has focused on pinpointing when during the process of oocyte maturation adjustment of sex ratio takes place. Additionally, there is growing support for the idea that there is hormonal control over the process of adjustment of sex ratio in birds. Whether steroid hormones represent direct mediators of the process, however, remains unclear. This review outlines the precise points during maturation of ovarian follicles during which adjustment of primary sex ratios could potentially occur, compiles the evidence for hormonal involvement in the process of primary adjustment of sex ratio, and discusses potential hormonal targets during maturation and fertilization of oocytes where hormones may trigger adjustment of sex ratio in birds.
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Affiliation(s)
- Kristen J Navara
- Department of Poultry Science, The University of Georgia, Athens, GA 30602, USA
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20
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Fouany MR, Sharara FI. Is there a role for DHEA supplementation in women with diminished ovarian reserve? J Assist Reprod Genet 2013; 30:1239-44. [PMID: 23737215 DOI: 10.1007/s10815-013-0018-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 05/17/2013] [Indexed: 01/27/2023] Open
Abstract
PURPOSE Poor ovarian reserve and poor ovarian response presents a challenge to IVF centers. Dehydroepiandrosterone (DHEA) supplementation is increasingly being used by many IVF centers around the world in poor responders despite the lack of convincing data. We therefore examined the rationale for the use of DHEA in poor responders, address the relevant studies, present new data, and address its potential mechanisms of action. METHODS All published articles on the role of DHEA in infertile women from 1990 to April 2013 were reviewed. RESULTS Several studies have suggested an improvement in pregnancy rates with the use of DHEA. Potential mechanisms include improved follicular steroidogenesis, increased IGF-1, acting as a pre-hormone for follicular testosterone, reducing aneuploidy, and increasing AMH and antral follicle count. While the role of DHEA is intriguing, evidence-based recommendations are lacking. CONCLUSIONS While nearly 25 % of IVF programs use DHEA currently, large randomized prospective trials are sorely needed. Until (and if) such trials are conducted, DHEA may be of benefit in suitable, well informed, and consented women with diminished ovarian reserve.
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Affiliation(s)
- Mazen R Fouany
- Department of Obstetrics and Gynecology, Charles Cole Memorial Hospital, Coudersport, PA, USA
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21
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Cryopréservation de la cohorte embryonnaire en cas de risque d’hyperstimulation : prévention et efficacité. ACTA ACUST UNITED AC 2013; 41:365-71. [DOI: 10.1016/j.gyobfe.2013.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 04/15/2013] [Indexed: 11/19/2022]
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22
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Murdoch B, Owen N, Stevense M, Smith H, Nagaoka S, Hassold T, McKay M, Xu H, Fu J, Revenkova E, Jessberger R, Hunt P. Altered cohesin gene dosage affects Mammalian meiotic chromosome structure and behavior. PLoS Genet 2013; 9:e1003241. [PMID: 23408896 PMCID: PMC3567145 DOI: 10.1371/journal.pgen.1003241] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/28/2012] [Indexed: 01/03/2023] Open
Abstract
Based on studies in mice and humans, cohesin loss from chromosomes during the period of protracted meiotic arrest appears to play a major role in chromosome segregation errors during female meiosis. In mice, mutations in meiosis-specific cohesin genes cause meiotic disturbances and infertility. However, the more clinically relevant situation, heterozygosity for mutations in these genes, has not been evaluated. We report here evidence from the mouse that partial loss of gene function for either Smc1b or Rec8 causes perturbations in the formation of the synaptonemal complex (SC) and affects both synapsis and recombination between homologs during meiotic prophase. Importantly, these defects increase the frequency of chromosomally abnormal eggs in the adult female. These findings have important implications for humans: they suggest that women who carry mutations or variants that affect cohesin function have an elevated risk of aneuploid pregnancies and may even be at increased risk of transmitting structural chromosome abnormalities.
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Affiliation(s)
- Brenda Murdoch
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Nichole Owen
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Michelle Stevense
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Helen Smith
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - So Nagaoka
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Terry Hassold
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Michael McKay
- Sydney University and the North Coast Cancer Institute, Lismore, New South Wales, Australia
| | - Huiling Xu
- Divisions of Research and Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Jun Fu
- Genomics, BioTec, Technische Universität Dresden, Dresden, Germany
| | - Ekaterina Revenkova
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Patricia Hunt
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
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23
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Horne SD, Abdallah BY, Stevens JB, Liu G, Ye KJ, Bremer SW, Heng HH. Genome constraint through sexual reproduction: application of 4D-Genomics in reproductive biology. Syst Biol Reprod Med 2013; 59:124-30. [DOI: 10.3109/19396368.2012.754969] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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24
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Follicular fluid protein content (FSH, LH, PG4, E2 and AMH) and polar body aneuploidy. J Assist Reprod Genet 2012; 29:1123-34. [PMID: 22890422 DOI: 10.1007/s10815-012-9841-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/25/2012] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Our objective was to identify a marker for oocyte aneuploidy in follicular fluid (FF) in women with an increased risk of oocyte aneuploidy after controlled ovarian hyperstimulation. MATERIALS AND METHODS Three groups of oocytes were constituted for polar body screening by FISH (chromosomes 13, 16, 18, 21 and 22): Group 1, advanced maternal age (n = 156); Group 2, implantation failure (i.e. no pregnancy after the transfer of more than 10 embryos; n = 101) and Group 3, implantation failure and advanced maternal age (n = 56). FSH and other proteins were assayed in the corresponding FF samples. RESULTS Of the 313 oocytes assessed, 35.78 % were abnormal. We found a significant difference between the follicular FSH levels in normal oocytes and abnormal oocytes (4.85 ± 1.75 IU/L vs. 5.41 ± 2.47 IU/L, respectively; p = 0.021). We found that the greater the number of chromosomal abnormalities per oocyte (between 0 and 3), the higher the follicular FSH level. CONCLUSION High FF FSH levels were associated with oocyte aneuploidy in women having undergone controlled ovarian hyperstimulation.
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Nagaoka SI, Hassold TJ, Hunt PA. Human aneuploidy: mechanisms and new insights into an age-old problem. Nat Rev Genet 2012; 13:493-504. [PMID: 22705668 PMCID: PMC3551553 DOI: 10.1038/nrg3245] [Citation(s) in RCA: 626] [Impact Index Per Article: 52.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Trisomic and monosomic (aneuploid) embryos account for at least 10% of human pregnancies and, for women nearing the end of their reproductive lifespan, the incidence may exceed 50%. The errors that lead to aneuploidy almost always occur in the oocyte but, despite intensive investigation, the underlying molecular basis has remained elusive. Recent studies of humans and model organisms have shed new light on the complexity of meiotic defects, providing evidence that the age-related increase in errors in the human female is not attributable to a single factor but to an interplay between unique features of oogenesis and a host of endogenous and exogenous factors.
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Affiliation(s)
- So I Nagaoka
- School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164, USA
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26
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Wang ZB, Schatten H, Sun QY. Why is chromosome segregation error in oocytes increased with maternal aging? Physiology (Bethesda) 2012; 26:314-25. [PMID: 22013190 DOI: 10.1152/physiol.00020.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is well documented that female fertility is decreased with advanced maternal age due to chromosome abnormality in oocytes. Increased chromosome missegregation is mainly caused by centromeric cohesion reduction. Other factors such as weakened homologous recombination, improper spindle organization, spindle assembly checkpoint (SAC) malfunction, chromatin epigenetic changes, and extra-oocyte factors may also cause chromosome errors.
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Affiliation(s)
- Zhen-Bo Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Yakut T, Karkucak M, Sher G, Keskintepe L. Comparison of aneuploidy frequencies between in vitro matured and unstimulated cycles oocytes by metaphase comparative genomic hybridization (mCGH). Mol Biol Rep 2011; 39:6187-91. [DOI: 10.1007/s11033-011-1436-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 12/19/2011] [Indexed: 10/14/2022]
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Gleicher N, Weghofer A, Barad DH. The role of androgens in follicle maturation and ovulation induction: friend or foe of infertility treatment? Reprod Biol Endocrinol 2011; 9:116. [PMID: 21849061 PMCID: PMC3170254 DOI: 10.1186/1477-7827-9-116] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 08/17/2011] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Effects of androgens on follicle maturation have been controversial for some time. Here, we review the potential of their applications in improving human ovulation induction, based on human and animal data, reported in the literature. METHODS We reviewed the published literature for the years 2005-2011, using relevant key words, in PubMed, Medline and Cochrane reviews, and then performed secondary reviews of referenced articles, which previously had not been known or preceded the searched time period. A total of 217 publications were reviewed. RESULTS Contrary to widely held opinion, recent data, mostly developed in the mouse, convincingly demonstrate essential contribution of androgens to normal follicle maturation and, therefore, female fertility. Androgens appear most engaged at preantral and antral stages, primarily affect granulosa cells, and exert effects via androgen receptors (AR) through transcriptional regulation but also in non-genomic ways, with ligand-activated AR modulating follicle stimulating hormone (FSH) activity in granulosa cells. While some androgens, like testosterone (T) and dehydroepiandrosterone (DHEA), appear effective in improving functional ovarian reserve (FOR) in women with diminished ovarian reserve (DOR), others may even exert opposite effects. Such differences in androgens may, at least partially, reflect different levels of agonism to AR. DISCUSSION Selective androgens appear capable of improving early stages of folliculogenesis. They, therefore, may represent forerunners of a completely new class of ovulation-inducing medications, which, in contrast to gonadotropins, affect follicle maturation at much earlier stages.
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Affiliation(s)
- Norbert Gleicher
- Center for Human Reproduction - New York, New York, USA
- Foundation for Reproductive Medicine, New York, New York, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andrea Weghofer
- Center for Human Reproduction - New York, New York, USA
- Department of Obstetrics and Gynecology, Medical University Vienna, Vienna, Austria
| | - David H Barad
- Center for Human Reproduction - New York, New York, USA
- Foundation for Reproductive Medicine, New York, New York, USA
- Departments of Epidemiology and Social Medicine and Obstetrics, Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York, USA
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Gleicher N, Barad DH. Dehydroepiandrosterone (DHEA) supplementation in diminished ovarian reserve (DOR). Reprod Biol Endocrinol 2011; 9:67. [PMID: 21586137 PMCID: PMC3112409 DOI: 10.1186/1477-7827-9-67] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/17/2011] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND With infertility populations in the developed world rapidly aging, treatment of diminished ovarian reserve (DOR) assumes increasing clinical importance. Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances with DOR, and is now utilized by approximately one third of all IVF centers world-wide. Increasing DHEA utilization and publication of a first prospectively randomized trial now warrants a systematic review. METHODS PubMed, Cochrane and Ovid Medline were searched between 1995 and 2010 under the following strategy: [<dehydroepiandrosterone or DHEA or androgens or testosterone > and <ovarian reserve or diminished ovarian reserve or ovarian function >]. Bibliographies of relevant publications were further explored for additional relevant citations. Since only one randomized study has been published, publications, independent of evidence levels and quality assessment, were reviewed. RESULTS Current best available evidence suggests that DHEA improves ovarian function, increases pregnancy chances and, by reducing aneuploidy, lowers miscarriage rates. DHEA over time also appears to objectively improve ovarian reserve. Recent animal data support androgens in promoting preantral follicle growth and reduction in follicle atresia. DISCUSSION Improvement of oocyte/embryo quality with DHEA supplementation potentially suggests a new concept of ovarian aging, where ovarian environments, but not oocytes themselves, age. DHEA may, thus, represent a first agent beneficially affecting aging ovarian environments. Others can be expected to follow.
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Affiliation(s)
- Norbert Gleicher
- Center for Human Reproduction (CHR) and Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - David H Barad
- Center for Human Reproduction (CHR) and Foundation for Reproductive Medicine, New York, NY, USA
- Departments of Epidemiology and Social Medicine and Obstetrics, Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, NY, USA
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Nagaoka SI, Hodges CA, Albertini DF, Hunt PA. Oocyte-specific differences in cell-cycle control create an innate susceptibility to meiotic errors. Curr Biol 2011; 21:651-7. [PMID: 21497085 DOI: 10.1016/j.cub.2011.03.003] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/14/2011] [Accepted: 03/01/2011] [Indexed: 11/25/2022]
Abstract
Segregation of homologs at the first meiotic division (MI) is facilitated by crossovers and by a physical constraint imposed on sister kinetochores that facilitates monopolar attachment to the MI spindle. Recombination failure or premature separation of homologs results in univalent chromosomes at MI, and univalents constrained to form monopolar attachments should be inherently unstable and trigger the spindle assembly checkpoint (SAC). Although univalents trigger cell-cycle arrest in the male, this is not the case in mammalian oocytes. Because the spindle assembly portion of the SAC appears to function normally, two hypotheses have been proposed to explain the lack of response to univalents: (1) reduced stringency of the oocyte SAC to aberrant chromosome behavior, and (2) the ability of univalents to satisfy the SAC by forming bipolar attachments. The present study of Mlh1 mutant mice demonstrates that metaphase alignment is not a prerequisite for anaphase onset and provides strong evidence that MI spindle stabilization and anaphase onset require stable bipolar attachment of a critical mass--but not all--of chromosomes. We postulate that subtle differences in SAC-mediated control make the human oocyte inherently error prone and contribute to the age-related increase in aneuploidy.
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Affiliation(s)
- So Iha Nagaoka
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA 99163, USA
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van den Berg IM, Eleveld C, van der Hoeven M, Birnie E, Steegers EAP, Galjaard RJ, Laven JSE, van Doorninck JH. Defective deacetylation of histone 4 K12 in human oocytes is associated with advanced maternal age and chromosome misalignment. Hum Reprod 2011; 26:1181-90. [PMID: 21349858 DOI: 10.1093/humrep/der030] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Chromosome segregation errors during human oocyte meiosis are associated with low fertility in humans and the incidence of these errors increases with advancing maternal age. Studies of mitosis and meiosis suggest that defective remodeling of chromatin plays a causative role in aneuploidy. We analyzed the histone deacetylation pattern during the final stages of human oocyte maturation to investigate whether defective epigenetic regulation of chromatin remodeling in human oocytes is related to maternal age and leads to segregation errors. METHODS Human surplus oocytes of different meiotic maturation stages [germinal vesicle (GV), metaphase (M)I and MII] were collected from standard IVF/ICSI treatments. Oocytes were analyzed for acetylation of different lysines of histone 4 (H4K5, H4K8, H4K12 and H4K16) and for α-tubulin. RESULTS Human GV oocytes had an intense staining of the chromatin for all four histone 4 lysine acetylations. MI and MII stage oocytes showed either normal deacetylation or various amounts of defective histone deacetylation. Residual H4K12 acetylation was more frequently found in oocytes obtained from older women, with a significant correlation between defective deacetylation and maternal age (r = 0.185, P = 0.007). Eighty-eight percent of the oocytes with residual acetylation had misaligned chromosomes, whereas only 33% of the oocytes that showed correct deacetylated chromatin had misaligned chromosomes (P < 0.001). CONCLUSIONS We conclude that defective deacetylation during human female meiosis increases with maternal age and is correlated with misaligned chromosomes. As chromosome misalignment predisposes to segregation errors, our data imply that defective regulation of histone deacetylation could be an important factor in age-related aneuploidy.
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Affiliation(s)
- I M van den Berg
- Department of Obstetrics and Gynaecology, Subdivision of Reproductive Medicine, Erasmus Medical Centre, Rotterdam, The Netherlands
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Gleicher N, Weghofer A, Barad DH. Defining ovarian reserve to better understand ovarian aging. Reprod Biol Endocrinol 2011; 9:23. [PMID: 21299886 PMCID: PMC3042920 DOI: 10.1186/1477-7827-9-23] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 02/07/2011] [Indexed: 11/10/2022] Open
Abstract
Though a widely utilized term and clinical concept, ovarian reserve (OR) has been only inadequately defined. Based on Medline and PubMed searches we here define OR in its various components, review genetic control of OR, with special emphasis on the FMR1 gene, and discuss whether diminished OR (DOR) is treatable. What is generally referred to as OR reflects only a small portion of total OR (TOR), a pool of growing (recruited) follicles (GFs) at different stages of maturation. Functional OR (FOR) depends on size of the follicle pool at menarche and the follicle recruitment rate. Both vary between individuals and, at least partially, are under genetic control. The FMR1 gene plays a role in defining FOR at all ages. Infertility treatments have in the past almost exclusively only centered on the last two weeks of folliculogenesis, the gonadotropin-sensitive phase. Expansions of treatments into earlier stages of maturation will offer opportunity to significantly improve ovarian stimulation protocols, especially in women with DOR. Dehydroepiandrosterone (DHEA) may represent a first such intervention. Data generated in DHEA-supplemented women, indeed, suggest a new ovarian aging concept, based on aging of ovarian environments and not, as currently is believed, aging oocytes.
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Affiliation(s)
- Norbert Gleicher
- Center for Human Reproduction - New York, New York, NY, USA
- Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Andrea Weghofer
- Center for Human Reproduction - New York, New York, NY, USA
- Department of Obstetrics and Gynecology, University of Vienna School of Medicine, Vienna, Austria
| | - David H Barad
- Center for Human Reproduction - New York, New York, NY, USA
- Department of Epidemiology and Social Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Obstetrics Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, NY, USA
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No relationship between the type of pituitary suppression for IVF and chromosomal abnormality rates of blastomeres: an observational study. Fertil Steril 2011; 95:563-7. [DOI: 10.1016/j.fertnstert.2010.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 05/01/2010] [Accepted: 05/11/2010] [Indexed: 11/21/2022]
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Abstract
Chromosome abnormalities in humans are strikingly associated with increasing maternal age. Studies in mice implicate loss of chromosome cohesion as an important cause of age-related meiotic errors in the oocyte.
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Affiliation(s)
- Patricia Hunt
- School for Molecular Biosciences, Washington State University, WA 99164, USA.
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Gleicher N, Weghofer A, Barad DH. Dehydroepiandrosterone (DHEA) reduces embryo aneuploidy: direct evidence from preimplantation genetic screening (PGS). Reprod Biol Endocrinol 2010; 8:140. [PMID: 21067609 PMCID: PMC2992540 DOI: 10.1186/1477-7827-8-140] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 11/10/2010] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances in women with diminished ovarian reserve (DOR), and to reduce miscarriage rates by 50-80%. Such an effect is mathematically inconceivable without beneficial effects on embryo ploidy. This study, therefore, assesses effects of DHEA on embryo aneuploidy. METHODS In a 1:2, matched case control study 22 consecutive women with DOR, supplemented with DHEA, underwent preimplantation genetic screening (PGS) of embryos during in vitro fertilization (IVF) cycles. Each was matched by patient age and time period of IVF with two control IVF cycles without DHEA supplementation (n = 44). PGS was performed for chromosomes X, Y, 13, 16, 18, 21 and 22, and involved determination of numbers and percentages of aneuploid embryos. RESULTS DHEA supplementation to a significant degree reduced number (P = 0.029) and percentages (P < 0.001) of aneuploid embryos, adjusted for relevant covariates. Short term supplementation (4-12 weeks) resulted in greatest reduction in aneuploidy (21.6%, 95% CI -2.871-46.031). DISCUSSION Beneficial DHEA effects on DOR patients, at least partially, are the likely consequence of lower embryo aneuploidy. DHEA supplementation also deserves investigation in older fertile women, attempting to conceive, where a similar effect, potentially, could positively affect public health.
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Affiliation(s)
- Norbert Gleicher
- Center for Human Reproduction (CHR) - New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Andrea Weghofer
- Center for Human Reproduction (CHR) - New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics and Gynecology, Vienna University School of Medicine, Vienna, Austria
| | - David H Barad
- Center for Human Reproduction (CHR) - New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Departments of Epidemiology and Social Medicine and Obstetrics, Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, NY, USA
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Santos MA, Teklenburg G, Macklon NS, Van Opstal D, Schuring-Blom GH, Krijtenburg PJ, de Vreeden-Elbertse J, Fauser BC, Baart EB. The fate of the mosaic embryo: chromosomal constitution and development of Day 4, 5 and 8 human embryos. Hum Reprod 2010; 25:1916-26. [PMID: 20519247 DOI: 10.1093/humrep/deq139] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Post-zygotic chromosome segregation errors are very common in human embryos after in vitro fertilization, resulting in mosaic embryos. However, the significance of mosaicism for the developmental potential of early embryos is unknown. We assessed chromosomal constitution and development of embryos from compaction to the peri-implantation stage. METHODS From 112 cryopreserved Day 4 human embryos donated for research, 21 were immediately fixed and all cells were analysed by fluorescent in situ hybridization (FISH) for chromosomes 1, 7, 13, 15, 16, 18, 21, 22, X and Y. The remaining 91 embryos were thawed, with 54 embryos undergoing biopsy of one or two cells which were fixed and analysed by FISH. Biopsied embryos were kept in standard culture conditions for 24 h. Embryos arrested before cavitation (n = 24) were fixed whereas developing Day 5 blastocysts (n = 24) were co-cultured for a further 72 h on an endometrial monolayer followed by fixation. Cell numbers were counted and all nuclei were analysed by FISH. Data from a previous FISH analysis on cryopreserved good-quality Day 5 blastocysts (n = 36) were also included in the present study. RESULTS FISH analysis was successful for 18 Day 4 fixed embryos and, according to our definition, 83% were mosaic and 11% showed a chaotic chromosomal constitution. FISH analysis of two blastomeres from Day 4 developing embryos showed that 54% were mosaic, 40% were normal and 6% were abnormal. Analysis of Day 4, 5 and 8 whole embryos showed a decrease in incidence of mosaicism over time, from 83% on Day 4 to 42% on Day 8. A significant positive correlation was observed between the total cell number and the percentage of normal cells in developing Day 5 and Day 8 embryos but not in developing Day 4 or embryos arrested before cavitation. CONCLUSIONS These data suggest that both the developmental arrest of a significant proportion of mosaic embryos on Day 4, and the cell death or reduced proliferation of aneuploid cells within an embryo may be responsible for the observed decrease of aneuploid blastomeres from compaction to the peri-implantation stage.
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Affiliation(s)
- Margarida Avo Santos
- Department of Reproductive Medicine and Gynaecology, University Medical Centre, Utrecht, The Netherlands.
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Santos MA, Kuijk EW, Macklon NS. The impact of ovarian stimulation for IVF on the developing embryo. Reproduction 2010; 139:23-34. [PMID: 19710204 DOI: 10.1530/rep-09-0187] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The use of assisted reproductive technologies (ART) has been increasing over the past three decades, and, in developed countries, ART account for 1-3% of annual births. In an attempt to compensate for inefficiencies in IVF procedures, patients undergo ovarian stimulation using high doses of exogenous gonadotrophins to allow retrieval of multiple oocytes in a single cycle. Although ovarian stimulation has an important role in ART, it may also have detrimental effects on oogenesis, embryo quality, endometrial receptivity and perinatal outcomes. In this review, we consider the evidence for these effects and address possible underlying mechanisms. We conclude that such mechanisms are still poorly understood, and further knowledge is needed in order to increase the safety of ovarian stimulation and to reduce potential effects on embryo development and implantation, which will ultimately be translated into increased pregnancy rates and healthy offspring.
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Affiliation(s)
- Margarida Avo Santos
- University Medical Centre Utrecht, Reproductive Medicine and Gynaecology, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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Gleicher N, Ryan E, Weghofer A, Blanco-Mejia S, Barad DH. Miscarriage rates after dehydroepiandrosterone (DHEA) supplementation in women with diminished ovarian reserve: a case control study. Reprod Biol Endocrinol 2009; 7:108. [PMID: 19811650 PMCID: PMC2764711 DOI: 10.1186/1477-7827-7-108] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 10/07/2009] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Dehydroepinadrosterone (DHEA) supplementation improves pregnancy chances in women with diminished ovarian reserve (DOR), by possibly reducing aneuploidy. Since a large majority of spontaneous miscarriages are associated with aneuploidy, one can speculate that DHEA supplementation may also reduce miscarriage rates. METHODS We retroactively compared, utilizing two independent statistical models, miscarriage rates in 73 DHEA supplemented pregnancies at two independent North American infertility centers, age-stratified, to miscarriages reported in a national U.S. in vitro fertilization (IVF) data base. RESULTS After DHEA supplementation the miscarriage rate at both centers was 15.1% (15.0% and 15.2%, respectively). For DHEA supplementation Mantel-Hänszel common odds ratio (and 95% confidence interval), stratified by age, was significantly lower, relative to odds of miscarriage in the general IVF control population [0.49 (0.25-0.94; p = 0.04)]. Miscarriage rates after DHEA were significantly lower at all ages but most pronounced above age 35 years. DISCUSSION Since DOR patients in the literature are reported to experience significantly higher miscarriage rates than average IVF patients, the here observed reduction in miscarriages after DHEA supplementation exceeds, however, all expectations. Miscarriage rates after DHEA not only were lower than in an average national IVF population but were comparable to rates reported in normally fertile populations. Low miscarriage rates, comparable to those of normal fertile women, are statistically impossible to achieve in DOR patients without assumption of a DHEA effect on embryo ploidy. Beyond further investigations in infertile populations, these data, therefore, also suggest the investigations of pre-conception DHEA supplementation in normal fertile populations above age 35 years.
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Affiliation(s)
- Norbert Gleicher
- The Center for Human Reproduction-New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA
| | - Eddy Ryan
- Toronto West Fertility Associates, Toronto, Canada
| | - Andrea Weghofer
- The Center for Human Reproduction-New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Department of Obstetrics and Gynecology, Vienna University School of Medicine, Vienna, Austria
| | | | - David H Barad
- The Center for Human Reproduction-New York and the Foundation for Reproductive Medicine, New York, NY, USA
- Departments of Epidemiology and Social Medicine and Obstetrics, Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, NY, USA
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Hunt PA, Susiarjo M, Rubio C, Hassold TJ. The bisphenol A experience: a primer for the analysis of environmental effects on mammalian reproduction. Biol Reprod 2009; 81:807-13. [PMID: 19458313 DOI: 10.1095/biolreprod.109.077008] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
It is increasingly evident that environmental factors are a veritable Pandora's box from which new concerns and complications continue to emerge. Although previously considered the domain of toxicologists, it is now clear that an understanding of the effects of the environment on reproduction requires a far broader range of expertise and that, at least for endocrine-disrupting chemicals, many of the tenets of classical toxicology need to be revisited. Indeed, because of the wide range of reproductive effects induced by these chemicals, interest among reproductive biologists has grown rapidly: in 2000, the program for the annual Society for the Study of Reproduction meeting included a single minisymposium on the fetal origins of adult disease, one platform session on endocrine disruption, and 23 toxicology poster presentations. In contrast, environmental factors featured prominently at the 2009 meeting, with strong representation in the plenary, minisymposia, platform, and poster sessions. Clearly, a lot has happened in a decade, and environmental issues have become an increasingly important research focus for reproductive biologists. In this review, we summarize some of the inherent difficulties in assessing environmental effects on reproductive performance, focusing on the endocrine disruptor bisphenol A (BPA) to illustrate important emerging concerns. In addition, because the BPA experience serves as a prototype for scientific activism, public education, and advocacy, these issues are also discussed.
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Affiliation(s)
- Patricia A Hunt
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington 99164-4660, USA.
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Verberg MFG, Macklon NS, Nargund G, Frydman R, Devroey P, Broekmans FJ, Fauser BCJM. Mild ovarian stimulation for IVF. Hum Reprod Update 2009; 15:13-29. [PMID: 19091755 DOI: 10.1093/humupd/dmn056] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Mild ovarian stimulation for in vitro fertilization (IVF) aims to achieve cost-effective, patient-friendly regimens which optimize the balance between outcomes and risks of treatment. METHODS Pubmed and Medline were searched up to end of January 2008 for papers on ovarian stimulation protocols for IVF. Additionally, references to related studies were selected wherever possible. RESULTS Studies show that mild interference with the decrease in follicle-stimulating hormone levels in the mid-follicular phase was sufficient to override the selection of a single dominant follicle. Gonadotrophin-releasing hormone antagonists compared with agonists reduce length and dosage of gonadotrophin treatment without a significant reduction in the probability of live birth (OR 0.86, 95% CI 0.72-1.02). Mild ovarian stimulation may be achieved with limited gonadotrophins or with alternatives such as anti-estrogens or aromatase inhibitors. Another option is luteinizing hormone or human chorionic gonadotrophin administration during the late follicular phase. Studies regarding these approaches are discussed individually; small sample size of single studies along with heterogeneity in patient inclusion criteria as well as outcomes analysed does not allow a meta-analysis to be performed. Additionally, the implications of mild ovarian stimulation for embryo quality, endometrial receptivity, cost and the psychological impact of IVF treatment are discussed. CONCLUSIONS Evidence in favour of mild ovarian stimulation for IVF is accumulating in recent literature. However, further, sufficiently powered prospective studies applying novel mild treatment regimens are required and structured reporting of the incidence and severity of complications, the number of treatment days, medication used, cost, patient discomfort and number of patient drop-outs in studies on IVF is encouraged.
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Affiliation(s)
- M F G Verberg
- Department of Reproductive Medicine and Gynaecology, University Medical Centre Utrecht, Utrecht, The Netherlands.
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Verberg MFG, Eijkemans MJC, Macklon NS, Heijnen EMEW, Baart EB, Hohmann FP, Fauser BCJM, Broekmans FJ. The clinical significance of the retrieval of a low number of oocytes following mild ovarian stimulation for IVF: a meta-analysis. Hum Reprod Update 2009; 15:5-12. [PMID: 19091754 DOI: 10.1093/humupd/dmn053] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Milder ovarian stimulation protocols for in vitro fertilization (IVF) are being developed to minimize adverse effects. Mild stimulation regimens result in a decreased number of oocytes at retrieval. After conventional ovarian stimulation for IVF, a low number of oocytes are believed to represent poor ovarian reserve resulting in reduced success rates. Recent studies suggest that a similar response following mild stimulation is associated with better outcomes. METHODS This review investigates whether the retrieval of a low number of oocytes following mild ovarian stimulation is associated with impaired implantation rates. Three randomized controlled trials comparing the efficacy of the mild ovarian stimulation regimen (involving midfollicular phase initiation of FSH and GnRH co-treatment) for IVF with a conventional long GnRH agonist co-treatment stimulation protocol could be identified by means of a systematic literature search. RESULTS These studies comprised a total of 592 first treatment cycles. Individual patient data analysis showed that the mild stimulation protocol results in a significant reduction of retrieved oocytes compared with conventional ovarian stimulation (median 6 versus 9, respectively, P < 0.001). Optimal embryo implantation rates were observed with 5 oocytes retrieved following mild stimulation (31%) versus 10 oocytes following conventional stimulation (29%) (P = 0.045). CONCLUSIONS The optimal number of retrieved oocytes depends on the ovarian stimulation regimen. After mild ovarian stimulation, a modest number of oocytes is associated with optimal implantation rates and does not reflect a poor ovarian response. Therefore, the fear of reducing the number of oocytes retrieved following mild ovarian stimulation appears to be unjustified.
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Affiliation(s)
- M F G Verberg
- Department of Reproductive Medicine and Gynaecology, University Medical Center, Utrecht, The Netherlands.
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Garcia-Cruz R, Roig I, Robles P, Scherthan H, Garcia Caldés M. ATR, BRCA1 and gammaH2AX localize to unsynapsed chromosomes at the pachytene stage in human oocytes. Reprod Biomed Online 2009; 18:37-44. [PMID: 19146767 DOI: 10.1016/s1472-6483(10)60422-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Asynapsis of homologous chromosomes at the pachytene stage has been associated with gametogenic failure and infertility, but the cellular mechanisms involved are currently unknown in human meiocytes. In mice, the protein encoded by the breast-cancer susceptibility gene Brca1 has been described to direct kinase ATR (ataxia telangiectasia and Rad3 related) to any unpaired DNA at the pachytene stage, where ATR triggers H2AX phosphorylation, resulting in the silencing of those chromosomes. In this study, the distribution of ATR, BRCA1 and the phosphorylated histone gammaH2AX is assessed by immunofluorescence in human oocytes and it is found that they localize at unpaired chromosomes at the pachytene stage. Evidence is shown to propose that BRCA1, ATR and gammaH2AX in the human may be part of a system such as the one previously described in mouse, which signals unsynapsed chromosomes at pachytene and may lead to their silencing.
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Affiliation(s)
- R Garcia-Cruz
- Departament de Biologia Cellular, Unitat de Biologia Cellular i Genètica Mèdica, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Hernandez Gifford JA, Hunzicker-Dunn ME, Nilson JH. Conditional deletion of beta-catenin mediated by Amhr2cre in mice causes female infertility. Biol Reprod 2009; 80:1282-92. [PMID: 19176883 DOI: 10.1095/biolreprod.108.072280] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Follicle-stimulating hormone (FSH) regulation of aromatase gene expression in vitro requires the transcriptional coactivator beta-catenin. To ascertain the physiological significance of beta-catenin in granulosa cells during folliculogenesis, mice homozygous for floxed alleles of beta-catenin were intercrossed with Amhr2cre mice. Conditional deletion of beta-catenin in 8-wk-old females occurred in derivatives of the Müllerian duct, granulosa cells and, surprisingly, in brain, pituitary, heart, liver, and tail. Female mice deficient for beta-catenin were infertile, despite reaching puberty and ovulating at the expected age, indications of apparently normal ovarian function. In contrast, their oviducts were grossly distended, with fewer but healthy oocytes. In addition, their uteri lacked implantation sites. Together, these two phenotypes could explain the complete loss of fertility. Nevertheless, although the ovary appeared normal, with serum estradiol concentrations in the normal range, there was marked animal-to-animal variation of mRNAs encoding beta-catenin and aromatase. Similarly, inhibin-alpha and luteinizing hormone receptor mRNAs varied considerably in whole ovaries, whereas pituitary Fshb mRNA was significantly reduced. Collectively, these features suggested cyclization recombination (CRE)-mediated recombination of beta-catenin may be unstable in proliferating granulosa cells, and therefore may mask the suspected steroidogenic requirement for beta-catenin. We tested this possibility by transducing primary cultures of granulosa cells from mice homozygous for floxed alleles of beta-catenin with a CRE-expressing adenovirus. Reduction of beta-catenin significantly compromised FSH stimulation of aromatase mRNA and subsequent production of estradiol. Collectively, these data suggest that FSH regulation of steroidogenesis requires beta-catenin, a role that remains hidden when tested through Amhr2cre-mediated recombination in vivo.
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Muhlhauser A, Susiarjo M, Rubio C, Griswold J, Gorence G, Hassold T, Hunt PA. Bisphenol A effects on the growing mouse oocyte are influenced by diet. Biol Reprod 2009; 80:1066-71. [PMID: 19164168 DOI: 10.1095/biolreprod.108.074815] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Growing evidence suggests that exposure to bisphenol A (BPA) has the ability to disrupt several different stages of oocyte development. To date, most attention has focused on the effects of BPA on the periovulatory oocyte, and considerable variation is evident in the results of these studies. In our own laboratory, variation in the results of BPA studies conducted at different times appeared to correlate with changes in mill dates of animal feed. This observation, coupled with reports by others that dietary estrogens in feed are a confounding variable in studies of endocrine-disrupting chemicals, prompted us to evaluate the effect of diet on the results of BPA studies of the periovulatory oocyte. Genetically identical females were placed on a high- or low-phytoestrogen diet prior to mating. Their female offspring were exposed to BPA, oocytes collected, and meiotic spindle and chromosome characteristics compared between control and BPA-treated females. We observed significant diet-related variation in both the frequency of abnormalities in oocytes from untreated females and in the response to BPA. Our results demonstrate that the impact of BPA on meiosis depends, at least in part, on diet. We suggest that variation in the conclusions of recent BPA studies reflects differences in the diets used, as well as other methodological differences. Because meiotic disturbances are a feature of all studies to date, however, we conclude that low levels of BPA adversely affect the meiotic process.
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Affiliation(s)
- Ailene Muhlhauser
- School of Molecular Biosciences, Washington State University, Pullman, Washington, USA
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Baart EB, Macklon NS, Fauser BJCM. Ovarian stimulation and embryo quality. Reprod Biomed Online 2009; 18 Suppl 2:45-50. [DOI: 10.1016/s1472-6483(10)60448-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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46
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Maternal age and risk for trisomy 21 assessed by the origin of chromosome nondisjunction: a report from the Atlanta and National Down Syndrome Projects. Hum Genet 2008; 125:41-52. [PMID: 19050929 DOI: 10.1007/s00439-008-0603-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
We examined the association between maternal age and chromosome 21 nondisjunction by origin of the meiotic error. We analyzed data from two population-based, case-control studies: Atlanta Down Syndrome Project (1989-1999) and National Down Syndrome Project (2001-2004). Cases were live born infants with trisomy 21 and controls were infants without trisomy 21 delivered in the same geographical regions. We enrolled 1,215 of 1,881 eligible case families and 1,375 of 2,293 controls. We report four primary findings. First, the significant association between advanced maternal age and chromosome 21 nondisjunction was restricted to meiotic errors in the egg; the association was not observed in sperm or in post-zygotic mitotic errors. Second, advanced maternal age was significantly associated with both meiosis I (MI) and meiosis II (MII). For example, compared to mothers of controls, mothers of infants with trisomy 21 due to MI nondisjunction were 8.5 times more likely to be >or=40 years old than 20-24 years old at the birth of the index case (95% CI=5.6-12.9). Where nondisjunction occurred in MII, mothers were 15.1 times more likely to be >or=40 years (95% CI = 8.4-27.3). Third, the ratio of MI to MII errors differed by maternal age. The ratio was lower among women <19 years of age and those >or=40 years (2.1, 2.3, respectively) and higher in the middle age group (3.6). Lastly, we found no effect of grand-maternal age on the risk for maternal nondisjunction. This study emphasizes the complex association between advanced maternal age and nondisjunction of chromosome 21 during oogenesis.
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Evolution of "determinants" in sex-determination: a novel hypothesis for the origin of environmental contingencies in avian sex-bias. Semin Cell Dev Biol 2008; 20:304-12. [PMID: 19073270 DOI: 10.1016/j.semcdb.2008.11.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 11/18/2008] [Accepted: 11/19/2008] [Indexed: 11/23/2022]
Abstract
Sex-determination is commonly categorized as either "genetic" or "environmental"-a classification that obscures the origin of this dichotomy and the evolution of sex-determining factors. The current focus on static outcomes of sex-determination provides little insight into the dynamic developmental processes by which some mechanisms acquire the role of sex determinants. Systems that combine "genetic" pathways of sex-determination (i.e., sex chromosomes) with "environmental" pathways (e.g., epigenetically induced segregation distortion) provide an opportunity to examine the evolutionary relationships between the two classes of processes and, ultimately, illuminate the evolution of sex-determining systems. Taxa with sex chromosomes typically undergo an evolutionary reduction in size of one of the sex chromosomes due to suppressed recombination, resulting in pronounced dimorphism of the sex chromosomes, and setting the stage for emergence of epigenetic compensatory mechanisms regulating meiotic segregation of heteromorphic sex chromosomes. Here we propose that these dispersed and redundant regulatory mechanisms enable environmental contingency in genetic sex-determination in birds and account for frequently documented context-dependence in avian sex-determination. We examine the evolution of directionality in such sex-determination as a result of exposure of epigenetic regulators of meiosis to natural selection and identify a central role of hormones in integrating female reproductive homeostasis, resource allocation to oocytes, and offspring sex. This approach clarifies the evolutionary relationship between sex-specific molecular genetic mechanisms of sex-determination and non-sex-specific epigenetic regulators of meiosis and demonstrates that both can determine sex. Our perspective shows how non-sex-specific mechanisms can acquire sex-determining function and, by establishing the explicit link between physiological integration of oogenesis and sex-determination, opens new avenues to the studies of adaptive sex-bias and sex-specific resource allocation in species with genetic sex-determination.
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Lan C, Xiao W, Xiaohui D, Hongling Y. Developmental competence and chromosomal aneuploidy of preimplantation embryos derived from rabbit oocytes grown in ovarian mesometrial grafts. Fertil Steril 2008; 91:1578-82. [PMID: 18996515 DOI: 10.1016/j.fertnstert.2008.09.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 09/15/2008] [Accepted: 09/29/2008] [Indexed: 11/16/2022]
Abstract
The quality of oocytes derived from rabbit ovarian grafts after cryopreservation and mesometrial autotransplantation was assessed according to the capacity to develop into offspring and the incidence of chromosome abnormalities of blastocyst embryos after fertilization. Ovarian cryopreservation and mesometrial transplantation do not affect the chromosome complement of blastocysts derived from oocytes grown in ovarian grafts, and oocytes retrieved from mesometrial grafts produce live offspring after fertilization.
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Affiliation(s)
- Chao Lan
- Infertility Center, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
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Verpoest W, Fauser B, Papanikolaou E, Staessen C, Van Landuyt L, Donoso P, Tournaye H, Liebaers I, Devroey P. Chromosomal aneuploidy in embryos conceived with unstimulated cycle IVF. Hum Reprod 2008; 23:2369-71. [DOI: 10.1093/humrep/den269] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Rutkowska J, Badyaev AV. Review. Meiotic drive and sex determination: molecular and cytological mechanisms of sex ratio adjustment in birds. Philos Trans R Soc Lond B Biol Sci 2008; 363:1675-86. [PMID: 18048292 PMCID: PMC2606724 DOI: 10.1098/rstb.2007.0006] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Differences in relative fitness of male and female offspring across ecological and social environments should favour the evolution of sex-determining mechanisms that enable adjustment of brood sex ratio to the context of breeding. Despite the expectation that genetic sex determination should not produce consistent bias in primary sex ratios, extensive and adaptive modifications of offspring sex ratio in relation to social and physiological conditions during reproduction are often documented. Such discordance emphasizes the need for empirical investigation of the proximate mechanisms for modifying primary sex ratios, and suggests epigenetic effects on sex-determining mechanisms as the most likely candidates. Birds, in particular, are thought to have an unusually direct opportunity to modify offspring sex ratio because avian females are heterogametic and because the sex-determining division in avian meiosis occurs prior to ovulation and fertilization. However, despite evidence of strong epigenetic effects on sex determination in pre-ovulatory avian oocytes, the mechanisms behind such effects remain elusive. Our review of molecular and cytological mechanisms of avian meiosis uncovers a multitude of potential targets for selection on biased segregation of sex chromosomes, which may reflect the diversity of mechanisms and levels on which such selection operates in birds. Our findings indicate that pronounced differences between sex chromosomes in size, shape, size of protein bodies, alignment at the meiotic plate, microtubule attachment and epigenetic markings should commonly produce biased segregation of sex chromosomes as the default state, with secondary evolution of compensatory mechanisms necessary to maintain unbiased meiosis. We suggest that it is the epigenetic effects that modify such compensatory mechanisms that enable context-dependent and precise adjustment of primary sex ratio in birds. Furthermore, we highlight the features of avian meiosis that can be influenced by maternal hormones in response to environmental stimuli and may account for the precise and adaptive patterns of offspring sex ratio adjustment observed in some species.
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Affiliation(s)
| | - Alexander V Badyaev
- Department of Ecology and Evolutionary Biology, University of ArizonaTucson, AZ 85721, USA
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