The chromosomal normality of unfertilized oocytes from patients with polycystic ovarian syndrome

Correlation of self-reported racial background to euploidy status and live birth rates in assisted reproductive technology cycles

PURPOSE

To determine whether the embryonic euploidy rate and live birth outcomes following single, euploid embryo transfer (SEET) differ among women of self-reported racial and ethnic backgrounds.

METHODS

This retrospective cohort study included all infertile patients of different self-reported racial backgrounds who underwent In vitro fertilization (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) and an autologous single euploid embryo transfer (SEET) from December 2015 to December 2019 at a single private and academic assisted reproduction technology center. Primary outcome measures included ploidy rates among different racial groups. Secondary outcomes included clinical pregnancy, clinical pregnancy loss, and live birth rates.

RESULTS

Five thousand five hundred sixty-two patients who underwent an IVF cycle with ICSI-PGT-A were included. A total of 24,491 blastocysts were analyzed. White participants had on average more euploid embryos and higher euploidy rates when compared to their counterparts (p ≤ 0.0001). However, after controlling for confounding factors, there was no association between race and the odds of having  a higher euploidy rate (aOR 1.31; 95% CI 0.63-2.17, p = 0.42). A total of 4949 patients underwent SEET. Pregnancy outcomes did not differ among patients of varying self-reported races.

CONCLUSIONS

Euploidy rates and pregnancy outcomes were comparable among patients of different racial backgrounds who underwent a SEET.

Association between maternal polycystic ovarian syndrome undergoing assisted reproductive technology and pregnancy complications and neonatal outcomes: a systematic review and meta-analysis

BACKGROUND

Polycystic ovarian syndrome (PCOS) is recognized as the most prevalent endocrine disorder among women of reproductive age. While the utilization of assisted reproductive technology (ART) has resulted in favorable outcomes for infertility treatment in PCOS patients, the inherent pathophysiological features of the condition give rise to complications and consequences during pregnancy and delivery for both the mother and offspring. This study was to assess the correlation between maternal PCOS and various pregnancy complications and neonatal outcomes undergone ART.

METHODS

A systematic search was conducted on PubMed, EmBase, and the Cochrane Library to identify observational studies that investigated the association between PCOS and the risk of various pregnancy complications and neonatal outcomes, including gestational diabetes mellitus (GDM), hypertension in pregnancy (PIH), preeclampsia (PE), preterm birth, abortion, congenital malformations (CA), small for gestational age (SGA), large for gestational age (LGA), low birth weight (LBW), macrosomia, neonatal intensive care unit (NICU) admission and birth weight. Eligible studies were selected based on predetermined inclusion and exclusion criteria. The meta-analysis was conducted using Review Manager and Stata software, with odds ratios (ORs) or mean difference (MD), confidence intervals (CIs), and heterogeneity (I2) being calculated. The search was conducted up to March 2023.

RESULTS

A total of 33 studies with a combined sample size of 92,810 participants were identified. The findings indicate that PCOS is significantly associated with an increased risk of GDM (OR 1.51, 95% CI:1.17-1.94), PIH (OR 1.72, 95% CI:1.25-2.39), PE (OR 2.12, 95% CI:1.49-3.02), preterm birth (OR 1.29, 95% CI:1.21-1.39), and LBW (OR 1.29, 95% CI:1.14-1.47). In subgroup analyses, the risks of GDM (OR 1.80, 95% CI:1.23-2.62) and abortion (OR 1.41, 95% CI:1.08-1.84) were elevated in fresh embryo transferred (ET) subgroup, whereas elevated risk of PE (OR 1.82, 95% CI:1.17-2.83) and preterm birth (OR 1.31, 95% CI:1.21-1.42) was identified in frozen ET subgroup. Whatever with or without hyperandrogenism, patients with PCOS had a higher risk in preterm birth (OR 1.69, 95% CI: 1.31-2.18; OR 1.24, 95% CI:1.02-1.50) and abortion (OR 1.38, 95% CI:1.12-1.71; OR 1.23, 95% CI:1.06-1.43).

CONCLUSION

Our findings suggest that individuals with PCOS undergone ART are at a notably elevated risk for experiencing pregnancy complications and unfavorable neonatal outcomes. Nevertheless, to establish a definitive association between PCOS and pregnancy-related outcomes, it is necessary to conduct extensive prospective, blinded cohort studies and effectively control for confounding variables.

Evaluation of pregnancy and neonatal outcomes according to the phenotypic types of polycystic ovary syndrome: A prospective study

OBJECTIVE

We aimed to compare pregnancy and neonatal outcomes in the phenotypic subtypes of patients with polycystic ovary syndrome (PCOS).

METHODS

This prospective cohort included the patients with PCOS (n = 121) diagnosed according to the presence of androgen excess, ovulatory dysfunction, and/or polycystic ovary morphology and healthy controls (n = 125). We stratified PCOS as phenotype A (n = 45), phenotype B (n = 8), phenotype C (n = 32) and phenotype D (n = 35) and followed throughout pregnancy, comparing their outcomes.

RESULTS

The study population had a mean age of 28.7 ± 4.9 years and a mean BMI of 31.6 kg/m2 with no difference between the groups. Primary cesarean deliveries were significantly more common in PCOS patients (23.3%) than in the control group (17.6%, P = 0.021). The phenotype A group had significantly higher rates of gestational diabetes mellitus (GDM) (42.2%, P < 0.001) and fetal macrosomia (14.6%, P = 0.002) compared with the control group (4.8% and 0.8%m respectively). We detected a significantly lower rate of normal risk score on the double screening test in the PCOS group (59.0%) than in the control group (75.4%) and in the other groups (P = 0.001).

CONCLUSION

The rates of GDM, fetal macrosomia, and cesarean section were higher in the PCOS group, depending on the phenotype. We observed changes in risk calculation according to phenotypic types at aneuploidy screening.

Sperm and Oocyte Chromosomal Abnormalities

Gametogenesis, the process of producing gametes, differs significantly between oocytes and sperm. Most oocytes have chromosomal aneuploidies, indicating that chromosomal aberrations in miscarried and newborn infants are of oocyte origin. Conversely, most structural anomalies are of sperm origin. A prolonged meiotic period caused by increasing female age is responsible for an increased number of chromosomal aberrations. Sperm chromosomes are difficult to analyze because they cannot be evaluated using somatic cell chromosome analysis methods. Nevertheless, researchers have developed methods for chromosome analysis of sperm using the fluorescence in situ hybridization method, hamster eggs, and mouse eggs, allowing for the cytogenetic evaluation of individual sperm. Reproductive medicine has allowed men with severe spermatogenic defects or chromosomal abnormalities to have children. However, using these techniques to achieve successful pregnancies results in higher rates of miscarriages and embryos with chromosomal abnormalities. This raises questions regarding which cases should undergo sperm chromosome analysis and how the results should be interpreted. Here, we reviewed clinical trials that have been reported on oocyte and sperm chromosome analyses. Examination of chromosomal abnormalities in gametes is critical in assisted reproductive technology. Therefore, it is necessary to continue to study the mechanism underlying gametic chromosomal abnormalities.

Gonadotropins as pharmacological agents in assisted reproductive technology and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy associated with subfertility/infertility and pregnancy complications. Most PCOS women opt for assisted reproductive technologies (ART) for successful conception; however, optimization of the relative doses of the gonadotropins [follicle-stimulating hormone (FSH), luteinizing hormone (LH)/human chorionic gonadotropin (hCG)] for appropriate steroidogenesis, without causing ovarian hyperstimulatory syndrome (OHSS), is challenging. Embryonic factors probably do not contribute to pregnancy loss in PCOS women, albeit hormonal imbalance impairs the metabolic microenvironment critical for oocyte maturation and endometrial receptivity. Certain clinical studies have confirmed the role of metabolic corrections in increasing the rate of pregnancy in PCOS women. This review focuses on the impact of untimely high LHCGR and/or LH levels on oocyte/embryo quality, pregnancy outcomes in ART, and exploring LHCGR as a potential drug target in PCOS women.

Does the risk of embryo abnormality increase in PCOS women? A secondary analysis of a multi-center randomized controlled trial

CONTEXT

Some studies reported the early miscarriage rate was higher in PCOS women. However, whether the risk of embryo abnormalities increases in PCOS women is lack of evidence.

OBJECTIVE

To evaluate the association between polycystic ovarian syndrome (PCOS) and embryo ploidy.

DESIGN

A secondary analysis of multi-center randomized controlled trial which was conducted from July 2017 to June 2018. The original intent was to identify whether preimplantation genetic test for aneuploidy (PGT-A) improves the live birth rate as compared with in-vitro fertilization (IVF).

SETTING

14 reproductive centers.

PATIENTS

190 patients diagnosed with PCOS and 1:1 age-matched non-PCOS patients were chosen from PGT-A group. A total of 380 patients with 1118 embryos were included in our study.

INTERVENTIONS

Women diagnosed with PCOS.

MAIN OUTCOME MEASURES

Embryonic aneuploidy and embryonic mosaic.

RESULTS

After adjusted for potential confounders, the rate of embryonic aneuploidy and embryonic mosaic in PCOS group were comparable with control group [embryonic aneuploid rate PCOS group: 14.0% vs control group: 18.3%, adjusted OR (95%CI): 0.78(0.54,1.12), P = 0.19; embryonic mosaic rate 10.9% vs 10.1%, adjusted OR (95%CI): 0.91(0.59,1.40), P = 0.66]. We further stratified PCOS women into four groups according to phenotype. The rate of aneuploid and mosaic embryos was comparable between each of PCOS phenotype and control group. There was still no significant difference of embryonic aneuploid and embryo mosaic rates within four phenotypes.

CONCLUSIONS

The risk of aneuploid and mosaic embryos was not increased in PCOS women. Thus, we suggests that the miscarriage rate arising from abnormal embryonic chromosomes could be similar between PCOS and non-PCOS women.

Among high responders, is oocyte development potential different in Rotterdam consensus PCOS vs non-PCOS patients undergoing IVF?

PURPOSE

To evaluate the oocyte potential to develop to blastocyst in Rotterdam consensus PCOS in women with hyper-responses requiring freeze-all embryos.

METHODS

Retrospective, single-academic center, cohort study of 205 patients who underwent freeze-all antagonist IVF cycles for OHSS risk between 2013 and 2019. Women in the PCOS group (n = 88) were diagnosed per the 2003 Rotterdam criteria. Control patients (n = 122) had no evidence of hyperandrogenism or menstrual disturbance. Data was compared by t-tests, chi-squared tests, or multivariate logistic regression (SPSS). Frozen blastocysts were Gardner's grade BB or better.

RESULTS

There was no difference in terms of number of oocytes collected (PCOS vs non-PCOS 27.7 ± 9.4 vs 25.9 ± 8.2, p = 0.157), number of MII (20.7 ± 8.0 vs 19.1 ± 6.6, p = 0.130), number of 2PN fertilized (15.6 ± 7.4 vs 14.4 ± 5.9, p = 0.220), and number of frozen blastocysts (7.8 ± 4.9 vs 7.1 ± 3.8, p = 0.272). In addition, fertilization rates (74 ± 17% vs 75 ± 17%, p = 0.730), blastulation rates per 2PN (51 ± 25% vs 51 ± 25%, p = 0.869), and blastulation rates per mature oocytes (37 ± 18% vs 37 ± 15%, p = 0.984) were all comparable between PCOS and controls, respectively. Moreover, there was no difference when comparing PCOS and controls in pregnancy rates (45/81 vs 77/122, p = 0.28) and clinical pregnancy rates (34/81 vs 54/122, p = 0.75), respectively. Multivariate logistic regression controlling for confounders failed to alter these results.

CONCLUSION

PCOS subjects do not seem to have altered oocyte potential as measured by number of MII oocytes collected, fertilization, and blastulation rates when compared to high-responder controls, with similar magnitude of stimulation.

Polycystic ovary syndrome phenotype does not have impact on oocyte morphology

PURPOSE

The primary objective of the present study of women participating in an ICSI program was to determine whether the morphologic quality of oocytes was related to the polycystic ovary syndrome (PCOS) phenotype.

METHODS

We performed a retrospective cohort study in the IVF unit at the Lille University Medical Center (Lille, France) between 2006 and 2015. Oocyte morphology (fragmented first polar body, abnormal zona pellucida, large perivitelline space, material in perivitelline space, abnormal shape of oocyte, granular cytoplasm and intracytoplasmic vacuoles) was evaluated in PCOS women and according to different subgroup (depending on the presence or absence of the cardinal features polycystic ovarian morphology (PCOM), hyperandrogenism (HA), and oligo-anovulation (OA)).

RESULTS

A total of 1496 metaphase II oocytes (n = 602 for phenotype A combining PCOM + HA + OA, n = 462 oocytes for phenotype C: PCOM + HA, and n = 432 for phenotype D: PCOM + OA) were assessed. The phenotypes A, C and D did not differ significantly with regard to the proportion of normal oocytes (adjusted percentages (95%CI): 35.2% (31.5 to 39.1%), 25.8% (21.9 to 29.9%) and 34.0% (29.7 to 38.6%), respectively: adjusted p = 0.13). Likewise, there were no significant intergroup differences in oocyte morphology. The ICSI outcome was not significantly associated with the PCOS phenotype.

CONCLUSION

The present study is the first to show that the PCOS phenotype (notably the presence vs. absence of OA and/or HA) is not significantly associated with the morphological quality of oocytes.

Molecular Features of Polycystic Ovary Syndrome Revealed by Transcriptome Analysis of Oocytes and Cumulus Cells

Polycystic ovary syndrome (PCOS) is typically characterized by a polycystic ovarian morphology, hyperandrogenism, ovulatory dysfunction, and infertility. Furthermore, PCOS patients undergoing ovarian stimulation have more oocytes; however, the poor quality of oocytes leads to lower fertilization and implantation rates, decreased pregnancy rates, and increased miscarriage rates. The complex molecular mechanisms underlying PCOS and the poor quality of oocytes remain to be elucidated. We obtained matched oocytes and cumulus cells (CCs) from PCOS patients, compared them with age-matched controls, and performed RNA sequencing analysis to explore the transcriptional characteristics of their oocytes and CCs. Moreover, we validated our newly confirmed candidate genes for PCOS by immunofluorescence. Unsupervised clustering analysis showed that the overall global gene expression patterns and transposable element (TE) expression profiles of PCOS patients tightly clustered together, clearly distinct from those of controls. Abnormalities in functionally important pathways are found in PCOS oocytes. Notably, genes involved in microtubule processes, TUBB8 and TUBA1C, are overexpressed in PCOS oocytes. The metabolic and oxidative phosphorylation pathways are also dysregulated in both oocytes and CCs from PCOS patients. Moreover, in oocytes, differentially expressed TEs are not uniformly dispersed in human chromosomes. Endogenous retrovirus 1 (ERV1) elements located on chromosomes 2, 3, 4, and 5 are rather highly upregulated. Interestingly, these correlate with the most highly expressed protein-coding genes, including tubulin-associated genes TUBA1C, TUBB8P8, and TUBB8, linking the ERV1 elements to the occurrence of PCOS. Our comprehensive analysis of gene expression in oocytes and CCs, including TE expression, revealed the specific molecular features of PCOS. The aberrantly elevated expression of TUBB8 and TUBA1C and ERV1 provides additional markers for PCOS and may contribute to the compromised oocyte developmental competence in PCOS patients. Our findings may also have implications for treatment strategies to improve oocyte maturation and the pregnancy outcomes for women with PCOS.

Is Intracytoplasmic Sperm Injection the Solution for all in Unexplained Infertility?

Intracytoplasmic sperm injection (ICSI) was first introduced as a supplemental method to conventional in vitro fertilization (c-IVF) for couples with severe male factor infertility to overcome the poor fertilization rate, while its indications expanded in current clinical practice and gained worldwide popularity. However, ICSI is invasive and crosses all natural barriers, raising several unresolved concerns regarding procedure-dependent and procedure-independent risks, as well as the characteristic of being labor-intensive and more expensive than c-IVF. This review is aimed to draw readers' attention, to the widespread use of ICSI worldwide, with its effectiveness in different indications of infertility, especially in those with unexplained infertility, as well as the cost-effectiveness of the ICSI-for-all strategy. Also, we covered current evidence on the short- and long-term safety of children born thanks to ICSI-aided conception. Further well-designed, adequately powered, and randomized controlled clinical trials are absolutely needed to arrive at a consensus on the use of ICSI over c-IVF in different populations.

MiRNA-155 regulates cumulus cells function, oocyte maturation, and blastocyst formation

Numerous oocytes are retrieved during in vitro fertilization from patients with polycystic ovary syndrome (PCOS). The poor quality of these oocytes leads to lower fertilization and decreases in cleavage and implantation. MiR-155 is one of the microRNA (miRNA) that is increased in serum and granulosa cells of PCOS patients. In this study, we investigate the effects of miR-155 expression and its target genes on oocyte maturation and embryo development. We used the calcium phosphate protocol to transfect vectors that contained miR-155 or miR-off 155 and alone eGFP into cumulus oophorus complex (COCs) of B6D2F1 female mice for in vitro maturation. Cumulus expansion, nuclear, and cytoplasmic maturation, as well as cleavage rates were determined in groups transfected and compared with the control groups. Quantitative real-time polymerase chain reaction was performed to analyze expression levels of miR-155 and the target genes in the cumulus cells, oocytes, and blastocysts. MiR-155 overexpression in COCs suppressed cumulus expansion, oocyte maturation, and inhibition of endogenous miR-155 by miR-off 155 improved cumulus expansion and oocyte maturation by downregulation and expression increase of the Smad2 and Bcl2 genes. On the other hand, overexpression and downregulation of miR-155 in the COCs led to increase and decrease in cleavage rates by changes in expressions of the Mecp2, Jarid2, and Notch1 genes, respectively (P &lt; 0.05). These results suggested that miR-155 overexpression in granulosa cells of PCOS patients can negatively affect nuclear and cytoplasmic maturation, but this miRNA expression has a positive impact on embryo development.

Homocysteine impairs porcine oocyte quality via deregulation of one-carbon metabolism and hypermethylation of mitochondrial DNA†

Homocysteine (Hcy) is an intermediate in the one-carbon metabolism that donates methyl groups for methylation processes involved in epigenetic gene regulation. Although poor oocyte quality in polycystic ovarian syndrome (PCOS) patients is associated with elevated Hcy concentration in serum and follicular fluid, whether Hcy directly affects oocyte quality and its mechanisms are poorly understood. Here we show that Hcy treatment impaired oocyte quality and developmental competence, indicated by significantly reduced survival rate, polar body extrusion rate, and cleavage rate. Hcy treatment resulted in mitochondrial dysfunction, with increased production of mitochondrial ROS, reduced mtDNA copy number, and the expression of 7 out of 13 mtDNA-encoded genes and 2 ribosome RNA genes, 12S rRNA and 16S rRNA. Upon Hcy treatment, the expression of one-carbon metabolic enzymes and DNMT1 was enhanced. Interestingly, DNA methyltransferase inhibitor 5'AZA rescued Hcy-induced mitochondrial dysfunction, impaired oocyte quality and developmental competence. Concurrently, expression of one-carbon metabolic enzymes and methylation status of mtDNA coding sequences were also normalized, at least partially, by 5'AZA treatment. Our findings not only extend the understanding about how Hcy induces poor oocyte quality, but also contribute to a novel angle of identifying targets for enhancing the quality of oocyte from PCOS patients.

Reproductive Outcomes of Women with Polycystic Ovarian Syndrome Following In-Vitro Fertilization — A Meta-Analysis and Systematic Review

Background: Polycystic ovarian syndrome (PCOS) is a common cause of infertility in women. In-vitro fertilization (IVF) is required in 20–30% of women with PCOS trying to conceive. This is associated with increased risk of multiple gestation and ovarian hyperstimulation syndrome. Improvements in IVF techniques, safety standards, and the increased use of frozen embryos in recent years have lead to improved outcomes for women with PCOS. We performed a systematic review and meta-analysis to compare these outcomes with women without PCOS.

Search Methods: A search of PubMed, EMBASE, the Cochrane Central Register of clinical trials, and Scopus databases for all articles published until November 16th, 2017 identified 21 studies comparing IVF outcomes in PCOS and non-PCOS women. Inclusion criteria were Rotterdam criteria PCOS, comparable IVF regimes, immediate IVF outcomes, and pregnancy outcomes. Studies were excluded if the control group included any PCOS criteria, donor oocytes, or in-vitro maturation.

Outcomes: No difference was observed in live birth rate per cycle in women with vs. without PCOS (RR [Formula: see text] 1.01 [0.89, 1.16]; [Formula: see text] 82%), but the live birth rate per first cycle in PCOS cycles (RR [Formula: see text] 0.93 [0.88, 0.99]) was slightly lower. There was also no difference in the clinical pregnancy rate (RR 1.02 [0.89, 1.17]) or biochemical pregnancy rate (RR 1.03 [0.99, 1.08]) observed between the two groups. PCOS was associated with a significantly higher number of oocytes retrieved (mean difference [Formula: see text] 3.6; 95% CI [2.8, 4.4]), risk of miscarriage (RR 2.90 [2.09, 4.02]), and risk of ovarian hyperstimulation syndrome (RR 3.42 [2.28, 5.13]) per cycle.

Conclusion: Despite a widespread perception of poor reproductive potential, women with PCOS experience IVF outcomes similar to those without PCOS. Although there is a slightly lower live birth rate during their first stimulation cycle, success rates are similar after multiple cycles. PCOS is associated with a higher risk of ovarian hyperstimulation syndrome. Further studies are required to mitigate this risk.

[Polycystic ovary syndrome does not affect blastulation nor cumulative live birth rates]

OBJECTIVES

Polycystic ovarian syndrome (PCOS) brings complications in the management of the assisted reproductive technology (ART) because of an oocyte quality probably impaired due to modifications of intra- and extra-ovarian factors. Our study aimed to investigate the extended culture in PCOS patients and its influence on the cumulative live birth rates.

METHODS

Fifty-nine PCOS patients (as defined by the Rotterdam criteria) and 114 normo-ovulatory patients (i.e. with tubal, male or idiopathic infertility, regular cycles and AMH>2ng/mL) aged<37years old who underwent a 1st or 2nd ART attempt with extended culture to day 6 were included from October 2015 to December 2017. The blastulation and cumulative live birth rates were compared between the two groups.

RESULTS

The PCOS and control patients were 32.22 and 32.91years old respectively (P=0.05). The median number of oocytes retrieved was significantly higher in the PCOS group and the median oocyte maturity rate significantly lower compared with controls. The blastulation rates were similar between the PCOS and the control groups, respectively 57.8% vs. 58.6%, P=0.88. Because of the risks of hyperstimulation syndrome, a freeze all strategy was achieved for 38.9% of PCOS patients vs. 14.0% of the control patients (P<0.01). The cumulative live birth rates were not statistically different: 31.7% in the PCOS group vs. 37.2% in the control group, P=0.50.

CONCLUSIONS

PCOS was not observed to affect the extended culture nor the cumulative live birth rates in comparison to normo-ovulatory patients, supporting the blastocyst transfer strategy as a suitable option to PCOS patients.

A meta-analysis of pregnancy-related outcomes and complications in women with polycystic ovary syndrome undergoing IVF

This meta-analysis aimed to study whether pregnancy-related outcomes and complications differed between patients with polycystic ovary syndrome (PCOS) and those with other causes of infertility who had undergone IVF. A systematic search of PubMed, Embase, the Cochrane Library and Chinese databases was carried out to identify relevant studies published before July 2018. Outcomes were expressed as odds ratios (OR) and 95% confidence intervals (CI). Subgroup analyses and sensitivity analyses were also conducted. Twenty-nine studies were identified for inclusion. Women with PCOS had higher risks of miscarriage (OR 1.41, 95% CI 1.04-1.91), ovarian hyperstimulation syndrome (OR 4.96, 95% CI 3.73-6.60), gestational diabetes mellitus (OR 2.67, 95% CI 1.43-4.98), pregnancy-induced hypertension (OR 2.06, 95% CI 1.45-2.91), preterm birth (OR 1.60, 95% CI 1.25-2.04) and large-for-gestational-age babies (OR 2.10, 95% CI 1.01-4.37). Women with PCOS showed similar rates of clinical pregnancy, multiple pregnancy, ectopic pregnancy, small for gestational age and congenital malformations, and a higher live birth rate, compared with women without PCOS. This study provides an update on and comprehensive evidence to support the observation that despite the fact that PCOS patients achieve a better live birth rate, physicians should continue to consider them to be at high risk of adverse pregnancy-related outcomes.

A Hyperandrogenic Environment Causes Intrinsic Defects That Are Detrimental to Follicular Dynamics in a PCOS Mouse Model

Polycystic ovary syndrome (PCOS) is a common cause of female infertility. Hyperandrogenism is both a major symptom and key diagnostic trait of PCOS; however, the direct impact of this androgen excess on ovarian dynamics is unclear. By combining a DHT-induced PCOS mouse model with an ex vivo follicle culture system, we investigated the impact of hyperandrogenism on ovarian function. Ovaries from PCOS mice exhibited the characteristic polycystic ovary morphology with numerous large cystic follicles and no corpora lutea present. Isolation and individual culture of preantral and antral follicles from PCOS mice resulted in slower growth rates during 5 days compared with the follicles isolated from control mice (P < 0.01). In contrast, preovulatory follicles from PCOS mice exhibited a significant increase in growth rate compared with controls (P < 0.01). Preantral follicles from PCOS ovaries maintained comparable follicular health as control follicles, but antral and preovulatory PCOS follicles exhibited reduced follicle health (P < 0.01) and survival rates (P < 0.01). Compared with controls, PCOS females also exhibited a poorer response to hyperstimulation (P < 0.01), impaired oocyte function evident by increased levels of reactive oxygen species (P < 0.01), and a reduction in on-time embryo development (P < 0.01). These results demonstrate that prolonged exposure to androgen excess leads to aberrant follicle development, which persists even after removal from the hyperandrogenic environment, causing perturbed follicular developmental trajectories. These findings indicate that an in vivo hyperandrogenic environment in patients with PCOS may intrinsically induce detrimental effects on follicles and oocytes.

Effects of propylene glycol or elevated luteinizing hormone during follicle development on ovulation, fertilization, and early embryo development

Seventeen nonlactating Holstein cows were superovulated in a Latin-square designed experiment to determine the effects of increased propylene glycol (PROP) and luteinizing hormone (LH) during antral follicle development on ovarian function, fertilization, and early embryo quality. PROP was orally drenched every 4 h for 7 days to induce hyperinsulinemia and associated metabolic changes. LH concentrations were altered by increasing LH (3-fold) during last 2 days of superovulation. Treatment groups were as follows: (1) control-oral drenching with water plus low-LH preparation; (2) high LH(HLH)-water plus HLH preparation; (3) PROP-drenching with PROP plus low LH; (4) PROP/HLH-PROP plus HLH. PROP increased glucose (P < 0.05) and insulin (P < 0.02) concentrations at all time points analyzed. Neither PROP nor LH affected numbers of follicles > 9 mm at time of gonadotropin-releasing hormone-induced LH surge, although percentage of these follicles that ovulated was decreased by both PROP (P = 0.002) and LH (P = 0.048). In addition, PROP tended (P = 0.056) to decrease total number of ovulations. PROP reduced (P = 0.028) fertilization rate, while LH tended (P = 0.092) to increase fertilization rate. There was no effect of either PROP or LH on any measure of embryo quality including percentage of embryos that were degenerate, quality 1, or quality 1 and 2 of total structures collected or fertilized structures. These results indicate that acute elevation in insulin during the preovulatory follicular wave can decrease percentage of large follicles that ovulate, particularly when combined with increased LH, and reduce fertilization of ovulated oocytes.

The high responder: a review of pathophysiology and outcomes during IVF treatment

This review attempts to summarize the known literature on high responders to ovarian stimulation during assisted reproductive techniques (ART). Response to gonadotrophins is subject to significant interindividual and intercycle variation, thus carrying a risk of high response or poor response to ovarian stimulation regimens. The main risk for high responders is the development of ovarian hyperstimulation syndrome (OHSS) which is associated with significant morbidity. Hence, the definition of high responders in the literature has primarily focussed on risk factors for OHSS. Strategies to reduce OHSS including tailoring of the ovarian stimulation regimens and adjusting gonadotrophin doses according to patient characteristics and findings during the cycle of stimulation. In addition, modifying the type of ovulation trigger used and adjuvant therapies, such as metformin, intravenous colloids and vascular endothelial growth factor blockers, have also been studied as options to reduce OHSS. Apart from the risk of OHSS, high response also appears to have an adverse impact on the oocyte and endometrium, though there is a paucity of data regarding the extent and mechanisms behind this impact.

Low aneuploidy rate in early pregnancy loss abortuses from patients with polycystic ovary syndrome

A prospective cohort study was conducted to determine whether chromosome aneuploidy increases the risk of early spontaneous abortions in patients with polycystic ovary syndrome (PCOS). A total of 1461 patients who conceived after IVF and embryo transfer were followed; 100 patients who had experienced clinical spontaneous abortion were recruited, 32 with PCOS and 68 without PCOS. Before 2013, genetic analysis comprised conventional cultured villus chromosome karyotyping and a multiplex ligation-dependent probe amplification subtelomere assay combined with fluorescence in-situ hybridization; since 2013, array-based comparative genomic hybridization technique combined with chromosome karyotyping has been used. Age, BMI, pregnancy history, gestational age and total gonadotrophin dosage did not differ significantly between the PCOS and non-PCOS groups. In the PCOS group, 28.1% of abortuses demonstrated aneuploidy, which was significantly lower (P = 0.001) than in the non-PCOS group (72.1%). Further statistical analyses controlling for maternal age demonstrated that abortuses of women with PCOS were significantly less (P = 0.001) likely to have chromosome aneuploidy. Embryonic aneuploidy does not play a vital role in early spontaneous abortion in women with PCOS. Maternal factors resulting in endometrial disorders are more likely to be responsible for the increased risk of early spontaneous abortion in patients with PCOS.

Abnormally activated one-carbon metabolic pathway is associated with mtDNA hypermethylation and mitochondrial malfunction in the oocytes of polycystic gilt ovaries

Polycystic ovarian syndrome (PCOS) is associated with hyperhomocysteinemia and polycystic ovaries (PCO) usually produce oocytes of poor quality. However, the intracellular mechanism linking hyperhomocysteinemia and oocyte quality remains elusive. In this study, the quality of the oocytes isolated from healthy and polycystic gilt ovaries was evaluated in vitro in association with one-carbon metabolism, mitochondrial DNA (mtDNA) methylation, and mitochondrial function. PCO oocytes demonstrated impaired polar body extrusion, and significantly decreased cleavage and blastocyst rates. The mitochondrial distribution was disrupted in PCO oocytes, together with decreased mitochondrial membrane potential and deformed mitochondrial structure. The mtDNA copy number and the expression of mtDNA-encoded genes were significantly lower in PCO oocytes. Homocysteine concentration in follicular fluid was significantly higher in PCO group, which was associated with significantly up-regulated one-carbon metabolic enzymes betaine homocysteine methyltransferase (BHMT), glycine N-methyltransferase (GNMT) and the DNA methyltransferase DNMT1. Moreover, mtDNA sequences coding for 12S, 16S rRNA and ND4, as well as the D-loop region were significantly hypermethylated in PCO oocytes. These results indicate that an abnormal activation of one-carbon metabolism and hypermethylation of mtDNA may contribute, largely, to the mitochondrial malfunction and decreased quality of PCO-derived oocytes in gilts.

Scientific Statement on the Diagnostic Criteria, Epidemiology, Pathophysiology, and Molecular Genetics of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous and complex disorder that has both adverse reproductive and metabolic implications for affected women. However, there is generally poor understanding of its etiology. Varying expert-based diagnostic criteria utilize some combination of oligo-ovulation, hyperandrogenism, and the presence of polycystic ovaries. Criteria that require hyperandrogenism tend to identify a more severe reproductive and metabolic phenotype. The phenotype can vary by race and ethnicity, is difficult to define in the perimenarchal and perimenopausal period, and is exacerbated by obesity. The pathophysiology involves abnormal gonadotropin secretion from a reduced hypothalamic feedback response to circulating sex steroids, altered ovarian morphology and functional changes, and disordered insulin action in a variety of target tissues. PCOS clusters in families and both female and male relatives can show stigmata of the syndrome, including metabolic abnormalities. Genome-wide association studies have identified a number of candidate regions, although their role in contributing to PCOS is still largely unknown.

Unaltered timing of embryo development in women with polycystic ovarian syndrome (PCOS): a time-lapse study

PURPOSE

Polycystic ovarian syndrome (PCOS) is a common cause of female infertility. Factors other than anovulation, such as low embryo quality have been suggested to contribute to the infertility in these women. This 2-year retrospective study used timelapse technology to investigate the PCOS-influence on timing of development in the pre-implantation embryo (primary endpoint). The secondary outcome measure was live birth rates after elective single-embryo transfer.

METHODS

In total, 313 embryos from 43 PCOS women, and 1075 embryos from 174 non-PCOS women undergoing assisted reproduction were included. All embryos were monitored until day 6. Differences in embryo kinetics were tested in a covariance regression model to account for potential confounding variables: female age, BMI, fertilization method and male infertility.

RESULTS

Time to initiate compaction and reach the morula stage as well as the duration of the 4th cleavage division was significantly shorter in PCOS embryos compared with non-PCOS embryos. No other kinetic differences were found at any time-points annotated. The proportion of multi-nucleated cells at the 2-cell stage was significantly higher in PCOS embryos compared with non-PCOS embryos. The live birth rates were comparable between the two groups.

CONCLUSION

The findings suggest that the causative factor for subfertility in PCOS is not related to timing of development in the pre-implantation embryo.

Impaired oocyte quality induced by dehydroepiandrosterone is partially rescued by metformin treatment

The present study evaluated the influence of hyperandrogenism on oocyte quality using a murine PCOS model induced by dehydroepiandrosterone (DHEA) and further explored the effect of metformin treatment. Female BALB/c mice were treated with a vehicle control or DHEA (6 mg /100 g body weight) or DHEA plus metformin (50 mg /100 g body weight) for 20 consecutive days. DHEA-induced mice resembled some characters of human PCOS, such as irregular sexual cycles and polycystic ovaries. After the model validation was completed, metaphase II (MII) oocytes were retrieved and subsequent analyses of oocyte quality were performed. DHEA-treated mice yielded fewer MII oocytes, which displayed decreased mtDNA copy number, ATP content, inner mitochondrial membrane potential, excessive oxidative stress and impaired embryo development competence compared with those in control mice. Metformin treatment partially attenuated those damages, as evidenced by the increased fertilization and blastocyst rate, ATP content, GSH concentration and GSH/GSSG ratio, and decreased reactive oxygen species levels. No significant difference in normal spindle assembly was observed among the three groups. During in vitro maturation (IVM), the periods of germinal vesicle breakdown (GVBD) and the first polar body (PB1) extrusion were extended and the maturation rate of GVBD oocytes was decreased in DHEA mice compared with controls. Metformin treatment decreased the time elapsed of GVBD while had no effect on PB1 extrusion. These results indicated that excessive androgen is detrimental to oocyte quality while metformin treatment is, directly or indirectly, beneficial for oocyte quality improvement.

Ontogeny of the ovary in polycystic ovary syndrome

Activation of primordial follicles into the growing pool, selection of the dominant follicle, and its eventual ovulation require complex endocrine and metabolic interactions as well as intraovarian paracrine signals to coordinate granulosa cell proliferation, theca cell differentiation, and oocyte maturation. Early preantral follicle development relies mostly upon mesenchymal-epithelial cell interactions, intraovarian paracrine signals, and oocyte-secreted factors, whereas development of the antral follicle depends on circulating gonadotropins as well as locally derived regulators. In women with polycystic ovary syndrome (PCOS), ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and altered intrafollicular paracrine signaling perturb the activation, survival, growth, and selection of follicles, causing accumulation of small antral follicles within the periphery of the ovary, giving it a polycystic morphology. Altered adipocyte-ovarian interactions further compound these adverse events on follicle development and also can harm the oocyte, particularly in the presence of increased adiposity. Finally, endocrine antecedents of PCOS occur in female infants born to mothers with PCOS, which suggests that interactions between genes and the maternal-fetal hormonal environment may program ovarian function after birth.

[Impact of polycystic ovary syndrome on oocyte and embryo quality]

This review analyzes the literature concerning oocyte and embryo quality, in case of in vitro fertilization (IVF) for women with polycystic ovary syndrome (PCOS). Alterations in oocyte quality, and consequently in embryo quality, may be due to endocrine and intra-ovarian paracrine changes. However, most of publications find similar biological and clinical results after IVF, with or without microinjection, for women with PCOS compared to those obtained in control populations. Subgroups of more pejorative outcome probably exist within PCOS population. Finally, obesity, which is frequent in PCOS, is clearly deleterious, and multidisciplinary care, including lifestyle modifications, is then needed.

Reproductive traits of polycystic ovary syndrome in female rhesus monkeys

The objective of this study was to set up a rhesus monkey model of polycystic ovary syndrome (PCOS), which is globally prevalent among reproductive-aged human women, and to understand the reproductive traits of PCOS female monkeys. Six adult female rhesus monkeys aged 6-10 a, were divided into a PCOS group and a control group. The PCOS group were given two cycles of subcutaneous injections of propionic acid testosterone (PAT), 3.5 mg/kg body weight, on day 1, day 3, and day 5 of the menstrual cycle, respectively, and then given muscle injections of human chorionic gonadotropin (HCG), 350 IU/kg body weight, on day 7, day 9, and day 11, respectively. Results showed that high levels of serum LH and T [(5.35±0.17) IU/L and (7.58±0.14) ng/mL, respectively], and a high ratio value of LH/FSH (5.35/1.30=4.12) were observed in the PCOS group. No significant differences were found in serum FSH, E2, and P in the PCOS group compared with those of the control. Polycystic ovaries in the PCOS monkeys were recorded by live ultrasound. The blastocysts rates of the PCOS vs. the control were 23.53% vs. 66.67%, and there was a significant difference between the two groups. This study shows that PAT coupled with HCG can induce PCOS in rhesus monkeys in the short term. The reproductive features of PCOS monkeys were similar to those of PCOS patients.

Achieving a successful pregnancy in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a disease of complex and still poorly understood cause and of variable phenotypes. It is characterized by anovulation, hyperandrogenism, and polycystic ovaries. Infertility is commonly present. A variety of methods has been used successfully to achieve pregnancy in women with PCOS. Maintenance of pregnancy is complicated by a higher rate of premature spontaneous abortions and high risk of gestational diabetes, hypertension, and preeclampsia. However, with careful monitoring and treatment, the outcome of pregnancy in most women with PCOS is excellent.

The impact of obesity on egg quality

Obesity in women is a concern in many countries. This causes numerous health issues; however, this review focuses on the impact of obesity on women's reproduction, and in particular the oocyte. Data from infertility clinics and experimental animal models that address the effects of obesity are presented. Bidirectional communication and metabolic support from the surrounding cumulus cells are critical for oocyte development, and the impact of obesity on these cells is also addressed. Both oocyte maturation and metabolism are impaired due to obesity, negatively impacting further development. In addition to reproductive hormones, obesity induced elevations in insulin, glucose, or free fatty acids, and changes in adipokines appear to impact the developmental competence of the oocyte. The data indicate that any one of these hormones or metabolites can impair oocyte developmental competence in vivo, and the combination of all of these factors and their interactions are the subject of ongoing investigations.

Polycystic ovary syndrome: etiology, pathogenesis and diagnosis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age, with a prevalence of up to 10%. Various diagnostic criteria have been proposed, generally centered around the features of hyperandrogenism and/or hyperandrogenemia, oligo-ovulation and polycystic ovarian morphology. Insulin resistance is present in a majority of cases, with compensatory hyperinsulinemia contributing to hyperandrogenism via stimulation of ovarian androgen secretion and inhibition of hepatic sex hormone-binding globulin production. Adipose tissue dysfunction has been implicated as a contributor to the insulin resistance observed in PCOS. Environmental and genetic factors also have a role in the development of PCOS. The syndrome is associated with numerous morbidities, including infertility, obstetrical complications, type 2 diabetes mellitus, cardiovascular disease, and mood and eating disorders. Despite these morbidities, PCOS may be common in our society owing to evolutionary advantages of the syndrome in ancient times, including smaller family sizes, reduced exposure to childbirth-related mortality, increased muscle mass and greater capacity to store energy. The diagnosis of PCOS hinges on establishing key features while ruling out other hyperandrogenic or oligo-ovulatory disorders. Treatment is focused on the goals of ameliorating hyperandrogenic symptoms, inducing ovulation and preventing cardiometabolic complications.

Extra- and intra-ovarian factors in polycystic ovary syndrome: impact on oocyte maturation and embryo developmental competence

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common metabolic dysfunction and heterogeneous endocrine disorder in women of reproductive age. Although patients with PCOS are typically characterized by increased numbers of oocytes retrieved during IVF, they are often of poor quality, leading to lower fertilization, cleavage and implantation rates, and a higher miscarriage rate.

METHODS

For this review, we searched the database MEDLINE (1950 to January 2010) and Google for all full texts and/or abstract articles published in English with content related to oocyte maturation and embryo developmental competence.

RESULTS

The search showed that alteration of many factors may directly or indirectly impair the competence of maturating oocytes through endocrine and local paracrine/autocrine actions, resulting in a lower pregnancy rate in patients with PCOS. The extra-ovarian factors identified included gonadotrophins, hyperandrogenemia and hyperinsulinemia, although intra-ovarian factors included members of the epidermal, fibroblast, insulin-like and neurotrophin families of growth factors, as well as the cytokines.

CONCLUSIONS

Any abnormality in the extra- and/or intra-ovarian factors may negatively affect the granulosa cell-oocyte interaction, oocyte maturation and potential embryonic developmental competence, contributing to unsuccessful outcomes for patients with PCOS who are undergoing assisted reproduction.

[Assisted reproductive technologies place]

There are three kinds of infertility treatment: medical treatment, surgical treatment and assisted reproductive technology (ART). ART includes intra uterine insemination (IUI), in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). ART technologies made a lot of progress last years and their field of applications extended. Through literature reviews, IUI is recommended for unexplained infertility and discussed for male or cervical infertility. IVF is recommended for tubal and unexplained infertility. Limits between IVF and ICSI in case of male infertility remains unclear. In non mal infertility ICSI is not recommended.

Metabolism and karyotype analysis of oocytes from patients with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with metabolic disturbances which include impaired insulin signalling and glucose metabolism in ovarian follicles. The oocyte is metabolically dependent upon its follicle environment during development, but it is unclear whether PCOS or polycystic ovarian (PCO) morphology alone affect oocyte metabolism and energy-demanding processes such as meiosis.

METHODS

Immature human oocytes were donated by PCOS (n = 14), PCO (n = 14) and control (n = 46) patients attending the assisted conception programme at Leeds Teaching Hospitals NHS Trust. Oocytes were cultured individually and carbohydrate metabolism was assessed during overnight in vitro maturation (IVM). Meiotic status was assessed and oocyte intracellular nicotinamide adenine dinucleotide phosphate (NAD(P)H) content and mitochondria activity were measured prior to karyotype analysis by multifluor in situ hybridization.

RESULTS

Patient aetiology had no significant effect on oocyte maturation potential or incidence of numerical chromosome abnormalities (44%), although PCOS and PCO oocytes were more likely to suffer predivision. Group G chromosomes were most likely to be involved in non-disjunction and predivision. PCOS was associated with increased glucose consumption (2.06 +/- 0.43 and 0.54 +/- 0.12 pmol/h for PCOS and control oocytes, respectively) and increased pyruvate consumption (18.4 +/- 1.2 and 13.9 +/- 0.9 pmol/h for PCOS and control oocytes, respectively) during IVM. Prior prescription of metformin significantly attenuated pyruvate consumption by maturing oocytes (8.5 +/- 1.8 pmol/h) from PCOS patients. Oocytes from PCO patients had intermediate metabolism profiles. Higher pyruvate turnover was associated with abnormal oocyte karyotypes (13.4 +/- 1.9 and 19.9 +/- 2.1 pmol/h for normal versus abnormal oocytes, respectively). Similarly, oocyte NAD(P)H content was 1.35-fold higher in abnormal oocytes.

CONCLUSIONS

The chromosomal constitution of in vitro matured oocytes from PCOS is similar to that of controls, but aspects of oocyte metabolism are perturbed by PCOS. Elevated pyruvate consumption was associated with abnormal oocyte karyotype.

Downregulation of both gene expression and activity of Hsp27 improved maturation of mouse oocyte in vitro

BACKGROUND

Heat shock protein 27 (Hsp27), a member of the small heat shock protein family, is an apoptosis regulator. Our previous proteomic study showed that Hsp27 mainly expressed in human oocyte, and that Hsp27 expression was downregulated in the ovaries derived from women with the polycystic ovary syndrome (PCOS), a well known endocrinal disorder with abnormal apoptotic activity and folliculogenesis. However, the exact effects of Hsp27 downregulation on oocyte development have not yet been clarified.

METHODS

The expression of Hsp27 gene was downregulated in the mouse oocytes cultured in vitro using siRNA adenovirus infection, while the activity of Hsp27 was decreased by microinjection of polyclonal Hsp27 antibody into the cytoplasm of germinal vesicle (GV) oocytes. Oocyte maturation rate was evaluated by morphological observation. Early stage of apoptosis was determined using Annexin-V staining analysis and some critical apoptotic factors and cytokines were also monitored at both mRNA level by real time RT-PCR and protein expression level by immunofluorescence and western blot.

RESULTS

Hsp27 expressed at high level in maturing oocytes. Infection with AdshHsp27, and microinjection of Hsp27 antibody into GV oocytes, resulted in the improved oocyte development and maturation. Germinal vesicle breakdown (GVBD) rates were significantly increased in two AdshHsp27-treated groups (88.7%, 86.0%) and Hsp27 antibody-injected group (77.0%) when compared with control (76.2% in AdGFP, 64.4% in IgG-injected), respectively. In addition, the rates of metaphase II (MII) development in two AdshHsp27-treated groups (73.8%, 76.4%) and Hsp27 antibody-injected group (67.3%) were higher than that in the controls (59.6% in AdGFP, 55.1% in IgG-injected). We also found that the rates of early stage of apoptosis in Hsp27 downregulated groups (46.5% and 45.6%) were higher than that in control group (34.1%) after 8 h of IVM. Similarly, downregulation of Hsp27 caused a significantly enhanced the expression of apoptotic factors (caspase 8, caspase 3) and cytokines (bmp 15 and gdf 9).

CONCLUSIONS

Downregulation of Hsp27 improved the maturation of mouse oocytes, while increased early stage of apoptosis in oocytes by inducing the activation of extrinsic, caspase 8-mediated pathway.

Vacuolated oocytes: fertilization and embryonic arrest following intra-cytoplasmic sperm injection in a patient exhibiting persistent oocyte macro vacuolization--case report

PURPOSE

To describe a case of homogeneous macro vacuolar formation in oocytes from a patient undergoing IVF/ICSI over 3 cycles and implications thereof.

METHODS

Case report and analysis of cycle outcomes including spindle visualization to determine severity of internal disruption caused.

RESULTS

Characteristic macro vacuoles (>25 microm diameter) were identified in the vast majority of oocytes. Spindle visualization identified that macro vacuoles were not associated with spindle displacement. IVF resulted in failed fertilization. Low numbers of fertilized oocytes were obtained through ICSI. The vast majority of embryos exhibited maturation arrest on day 2.

CONCLUSIONS

It is likely that persistent Oocyte Macro Vacuolization is the cause of infertility in this patient. It probably has a biological basis and possibly a genetic cause, resulting in either uncontrollable endocytosis or poor exocytosis and consequent vacuolar formation.

Implications of polycystic ovary syndrome on oocyte development

Human follicle development requires the recruitment of primordial follicles into a cohort of growing follicles from which one follicle is selected to ovulate a mature oocyte. During this developmental process, complex endocrine and intraovarian paracrine signals create a changing intrafollicular hormonal milieu. With this microenvironment, appropriate cumulus cell-oocyte signaling governs oocyte developmental competence, defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. Many of these mechanisms are perturbed in polycystic ovary syndrome (PCOS), a heterogeneous syndrome characterized by ovarian hyperandrogenism, hyperinsulinemia from insulin resistance, and reduced fecundity. In addition to these endocrinopathies, PCOS also is characterized by paracrine dysregulation of follicle development by intraovarian proteins of the transforming growth factor-beta family. Consequently, PCOS patients undergoing ovarian stimulation for in vitro fertilization are at increased risks of impaired oocyte developmental competence, implantation failure, and pregnancy loss. Recent data demonstrate links between endocrine/paracrine factors and oocyte gene expression in PCOS and suggest that new clinical strategies to optimize developmental competence of PCOS oocytes should target correction of the entire follicle growth and oocyte development process.

Polycystic ovary syndrome and oocyte developmental competence

Folliculogenesis is a complex process, in which multiple endocrine and intraovarian paracrine interactions create a changing intrafollicular microenvironment for appropriate oocyte development. Within this microenvironment, bidirectional cumulus cell-oocyte signaling governs the gradual acquisition of developmental competence by the oocyte, defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. These regulatory mechanisms of follicle growth, controlled in part by the oocyte itself, are susceptible to derangement in polycystic ovary syndrome (PCOS), a heterogeneous syndrome characterized by ovarian hyperandrogenism, insulin resistance, and paracrine dysregulation of follicle development. Consequently, only a subset of PCOS patients experience reduced pregnancy outcome after ovarian stimulation for in vitro fertilization. Recent data implicate functional associations between endocrine/paracrine abnormalities, metabolic dysfunction, and altered oocyte gene expression with impaired oocyte developmental competence in women with PCOS. Therefore, an understanding of how developmentally relevant endocrine/paracrine factors interact to promote optimal oocyte developmental is crucial to identify those PCOS patients who might benefit from long-term correction of follicle growth to improve fertility, optimize follicular responsiveness to gonadotropin therapy, and enhance pregnancy outcome by in vitro fertilization.

Genome instability is increased in lymphocytes of women with polycystic ovary syndrome and is correlated with insulin resistance

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with insulin resistance and reproductive and metabolic abnormalities. The potential genetic contributors to PCOS are unclear. We tested the hypothesis that genomic instability (chromosome malsegregation and DNA damage) is increased in PCOS.

METHODS

Overweight age, weight and BMI-matched women with (n=14) and without (n=16) PCOS (age 34.2+/-6.0 years, weight 90.7+/-14.5 kg, BMI 34.0+/-5.6 kg/m(2), mean+/-S.D.) were assessed for chromosome malsegregation (assessed by X chromosome chromogenic in situ hybridisation) and micronucleus frequency (assessed by the cytokinesis block micronucleus index) in lymphocytes.

RESULTS

Women with PCOS had significantly elevated genomic instability as demonstrated by a significantly higher number of binucleated lymphocytes containing micronuclei, total number of micronuclei, a higher proportion of aneuploid X chromosome signals (2:1 X and 3:1 X) and a lower proportion of normal X chromosome segregation signals (2:2 X) in binucleated lymphocytes than women without PCOS. Surrogate measures of insulin resistance positively correlated with the proportion of aneuploid cells (2:1; 3:1 X chromosome signals) and inversely with the proportion of normal cells (2:2 X chromosome signals).

CONCLUSION

Women with PCOS display increased genomic instability (higher micronuclei and chromosome malsegregation) compared to women without PCOS and this increase may be related to the insulin resistance phenotype.

Lack of association between polycystic ovary syndrome and embryonic aneuploidy

OBJECTIVE

To determine whether women with polycystic ovary syndrome (PCOS) are at increased risk for embryonic aneuploidy.

DESIGN

Retrospective cohort study.

SETTING

Academic teaching department, privately owned preimplantation genetics laboratory, and academically affiliated, private infertility center.

PATIENT(S)

The study included 174 women, ages 27-45 years, who underwent a single cycle of controlled ovarian hyperstimulation with gonadotropins for in vitro fertilization. Amongst those, 74 were proven patients with PCOS, and 100 were control women with proven absence of PCOS.

INTERVENTION(S)

Preimplantation genetic diagnosis for chromosomes X, Y, 13, 15, 16, 17, 18, 21, and 22.

MAIN OUTCOME MEASURE(S)

Embryonic morphology, in vitro fertilization cycle outcome parameters, and euploidy and aneuploidy rates.

RESULT(S)

Women with PCOS demonstrated similar overall percentages of euploid embryos (49.1% +/- 28.1) when compared with control women (51.8% +/- 30.1). However, a statistically significantly higher oocyte yield in patients with PCOS (22.8 +/- 9.8 vs. 16.5 +/- 7.6) resulted in statistically significantly higher absolute numbers of euploid embryos (3.3 +/- 2.1 vs. 2.4 +/- 2.0). When stratified for age (<38 y and >or=38 y) and egg numbers (10-20 and >20), euploidy rates still did not vary between study and control patients. High-responder patients with PCOS showed, however, statistically significantly reduced clinical- (42.9% vs. 69.0%) and ongoing-pregnancy rates (40.5% vs. 65.5%) compared with high-responder control women.

CONCLUSION(S)

Women with PCOS are not at increased risk for embryonic aneuploidy in the course of in vitro fertilization treatment. Indeed, because of their larger oocyte numbers, they produce more euploid embryos but have lower pregnancy rates after high oocyte yields. This lower pregnancy rate is, thus, not genetically caused and requires further investigation.

Polycystic ovary syndrome and its developmental origins

The prenatal testosterone (T)-treated adult female rhesus monkey is one animal model of polycystic ovary syndrome (PCOS) in women, with early prenatal T excess programming a permanent PCOS-like phenotype characterized by luteinizing hormone (LH) hypersecretion from reduced hypothalamic sensitivity to steroid negative feedback and relative insulin excess from increased abdominal adiposity. These combined reproductive and metabolic abnormalities are associated with ovarian hyperandrogenism and follicular arrest in adulthood, as well as premature follicle differentiation and impaired embryo development during gonadotropin therapy for in vitro fertilization (IVF). A second animal model for PCOS, the prenatal T-treated sheep also is characterized by LH hypersecretion from reduced hypothalamic sensitivity to steroid negative feedback, persistent follicles and insulin resistance, but also is associated with intrauterine growth retardation and compensatory growth after birth. The ability of prenatal T excess in both species to alter the developmental trajectory of multiple organ systems in utero provides evidence that the hormonal environment of intrauterine life programs target tissue differentiation, raising the possibility that T excess in human fetal development promotes PCOS in adulthood. Such a hypothesis must include data from clinical studies of PCOS women to clarify the homology between these PCOS-like animal models and PCOS per se in reproductive and metabolic function. Future studies should develop new clinical strategies that improve pregnancy outcome and minimize pregnancy loss in women with disorders of insulin action, including PCOS, obesity and diabetes mellitus as well as minimize transgenerational susceptibility to adult PCOS and its metabolic derangements in male close relatives.

Gender effects on the incidence of aneuploidy in mammalian germ cells

Aneuploidy occurs in 0.3% of newborns, 4% of stillbirths, and more than 35% of all human spontaneous abortions. Human gametogenesis is uniquely and gender-specific susceptible to errors in chromosome segregation. Overall, between 1% and 4% of sperm and as many as 20% of human oocytes have been estimated by molecular cytogenetic analysis to be aneuploid. Maternal age remains the paramount aetiological factor associated with human aneuploidy. The majority of extra chromosomes in trisomic offspring appears to be of maternal origin resulting from nondisjunction of homologous chromosomes during the first meiotic division. Differences in the recombination patterns between male and female meiosis may partly account for the striking gender- and chromosome-specific differences in the genesis of human aneuploidy, especially in aged oocytes. Nondisjunction of entire chromosomes during meiosis I as well as premature separation of sister chromatids or homologues prior to meiotic anaphase can contribute to aneuploidy. During meiosis, checkpoints at meiotic prophase and the spindle checkpoint at M-phase can induce meiotic arrest and/or cell death in case of disturbances in pairing/recombination or spindle attachment of chromosomes. It has been suggested that gender differences in aneuploidy may result from more permissive checkpoints in females than males. Furthermore, age-related loss of chromosome cohesion in oocytes as a cause of aneuploidy may be female-specific. Comparative data about the susceptibility of human male and female germ cells to aneuploidy-causing chemicals is lacking. Increases of aneuploidy frequency in sperm have been shown after exposure to therapeutic drugs, occupational agents and lifestyle factors. Conversely, data on oocyte aneuploidy caused by exogenous agents is limited because of the small numbers of oocytes available for analysis combined with potential maternal age effects. The vast majority of animal studies on aneuploidy induction in germ cells represent cause and effect data. Specific studies designed to evaluate possible gender differences in induction of germ cell aneuploidy have not been found. However, the comparison of rodent data available from different laboratories suggests that oocytes are more sensitive than male germ cells when exposed to chemicals that effect the meiotic spindle. Only recently, in vitro experiments, analyses of transgenic animals and knockdown of expression of meiotic genes have started to address the molecular mechanisms underlying chromosome missegregation in mammalian germ cells whereby striking differences between genders could be shown. Such information is needed to clarify the extent and the mechanisms of gender effects, including possible differential susceptibility to environmental agents.

The occurrence of aneuploidy in human: lessons from the cytogenetic studies of human oocytes

During the last 4 decades, the cytogenetic investigation of human oocytes has never stopped to progress, according to the advents of new technologies. Both karyotyping and molecular cytogenetic studies have been reported to date, providing a large body of data on the incidence and the distribution of chromosomal abnormalities in human female gametes. However, these studies display a great variability in results, which may be essentially attributable to the limitations of these techniques when applied to human oocytes. The most relevant analysis have led to the estimate that 15-20% of human oocytes present chromosome abnormalities, and they have emphasized the implication of both whole chromosome nondisjunction and chromatid separation in the occurrence of aneuploidy in human oocytes. The effect of advanced maternal age on the incidence of aneuploidies in human oocytes has also been clearly evidenced by recent reports based on large sample of oocytes or polar bodies, whereas most of initial studies have failed to confirm any relationship between maternal age and aneuploidy in human oocytes.

A meta-analysis of outcomes of conventional IVF in women with polycystic ovary syndrome

This meta-analysis was conducted to compare outcomes of conventional IVF in women presenting with polycystic ovary syndrome (PCOS) and non-PCOS patients. Studies in which PCOS patients undergoing IVF were compared with a matched--no male factor--control group were considered for this review. A definition consistent with the Rotterdam consensus criteria of PCOS was required, and all patients within a given study had to be treated with the same ovarian stimulation protocol. Information regarding patient characteristics and pregnancy outcome was also required. Nine out of 290 identified studies reporting data on 458 PCOS patients (793 cycles) and 694 matched controls (1116 cycles) fulfilled these inclusion criteria. PCOS patients demonstrated a significantly reduced chance of oocyte retrieval per started cycle, odds ratio (OR) = 0.5 [95% confidence interval (CI) = 0.2-1.0]. However, no difference was observed in chance of embryo transfer per oocyte retrieval between the groups (OR = 0.7, 95% CI = 0.4-1.3). Significantly more oocytes per retrieval were obtained in PCOS patients compared with controls [random effects estimate 3.4 [95% (CI) = 1.7-5.1)]. The number of oocytes fertilized did not differ significantly between PCOS patients and controls, weighted mean difference (WMD) 0.1 oocytes (95% CI = 21.4-1.6). No significant difference was observed in the clinical pregnancy rates per started cycle, OR = 1.0 (95% CI = 0.8-1.3). The incidence of ovarian hyperstimulation syndrome (OHSS) after oocyte retrieval was rarely reported. This meta-analysis demonstrates an increased cancellation rate, but more oocytes retrieved per retrieval and a lower fertilization rate in PCOS undergoing IVF. Overall, PCOS and control patients achieved similar pregnancy and live birth rates per cycle.

IVF versus ICSI in sibling oocytes from patients with polycystic ovarian syndrome: a randomized controlled trial

BACKGROUND

This study compares the fertilization rate and embryonic development of oocytes randomly inseminated by conventional IVF or ICSI in patients with polycystic ovarian syndrome (PCOS) and normozoospermic semen during IVF cycles.

METHODS

Sibling oocytes were randomized to be inseminated either by ICSI or IVF. Fertilization rate (two pronuclei/COC), day 2 embryonic morphology and rate of development were assessed.

RESULTS

A total of 1089 cumulus-oocyte complexes (COC) were collected in 60 cycles (mean+/-SD, 18.2 +/- 7.2). Totals of 541 and 548 COC were inseminated by IVF and ICSI respectively, with a significantly higher fertilization rate in the ICSI group (ICSI versus IVF, 72.3 +/- 15.5 versus 44.8 +/- 25.1%). No fertilization failure occurred in the group of oocytes inseminated by ICSI, whereas the COC in nine patients (15%) inseminated by IVF had complete fertilization failure. The day 2 embryonic morphology and rate of development were not different regardless of the insemination method.

CONCLUSIONS

Our results suggested that another randomized controlled study, randomizing patients instead of sibling oocytes, should be undertaken to compare the pregnancy rate per started cycle and to see whether ICSI should be performed on all, or at least on a portion of, oocytes for patients with PCOS undergoing IVF cycles.

The chromosomal analysis of human oocytes. An overview of established procedures

The cytogenetic survey of mature human oocytes has been and remains a subject of great interest because of the prevalence of aneuploidy of maternal origin in abnormal human conceptuses, and the lack of understanding about the non-disjunction processes in human meiosis. The first attempts to analyse the chromosomal content of human female gametes were made in the early 1970s, and led to limited data because of the paucity of materials and the inadequacy of the procedure used. The years to follow brought a resurgence of interest in this field, because of the development of human IVF techniques which made oocytes unfertilized in vitro available for cytogenetic analysis. Numerous studies have since been performed. However, the difficulties in obtaining good chromosome preparations and of performing accurate chromosome identification have reduced the viability of these studies, resulting in large variations in the reported incidences of chromosomal abnormalities. The further introduction of new procedures for oocyte fixation and the screening of large oocyte samples have allowed more reliable data to be obtained and to identify premature chromatid separation as a major mechanism in aneuploidy occurrence. The last decade has been privileged to witness the adaptation of molecular cytogenetic techniques to human oocytes, and thus various powerful procedures have been tried not only on female gametes, but also on polar bodies, involving sequential and multicolour fluorescent in situ hybridization (FISH) labelling, comparative genomic hybridization (CGH), spectral karyotyping and alternative methods such as primed in situ labelling (PRINS) and peptide nucleic acid (PNA) techniques. A large body of data has been obtained, but these studies also display a great variability in the frequency of abnormalities, which may be essentially attributable to the technical limitations of these in situ methods when applied to human oocytes. However, molecular cytogenetic approaches have also evidenced the co-existence of both whole chromosome non-disjunction and chromatid separation in maternal aneuploidy. In addition, the extension of these techniques to oocyte polar body materials has provided additional data on the mechanism of meiotic malsegregation. Improvements of some of these techniques have already been reported. The further development of new approaches for the in situ analysis of human meiosis will increase the impact of cytogenetic investigation of human oocytes in the understanding of aneuploidy processes in humans.

The incidence of aneuploidy in human oocytes assessed by conventional cytogenetic analysis

Human oocytes failing to fertilize during assisted reproduction are an important source of information for assessing incidence and causal mechanisms of maternal aneuploidy. This review describes the techniques of conventional oocyte chromosome analysis and evaluates the results of 59 studies comprising a total of>10,000 female gametes. The mean rate of aneuploidy (hypohaploidy + hyperhaploidy) amounts to approximately 20%, but this incidence is reduced as soon as possible artifacts introduced by the fixation technique are taken into consideration. It is therefore concluded that a realistic value for numerical abnormalities arising during first meiotic division lies between 12 and 15%. All chromosome groups are affected by aneuploidy but the actually observed frequencies exceed the expected frequencies in groups D, E, and G. Two aneuploidy-causing mechanisms have been identified in human oocytes: nondisjunction, resulting in the loss or gain of whole chromosomes, and predivision, resulting in the loss or gain of single chromatids. A brief analysis including only aneuploid complements with one extra or missing chromosome/chromatid shows a slight increase in predivision (52.9%) compared with nondisjunction (47.1%). Finally, suggestions for future studies are given since, for instance, the presentation of results and the use of cytogenetic nomenclature have not been uniform.

Assisted reproduction in the treatment of polycystic ovarian syndrome

Treatment of patients with polycystic ovary syndrome (PCOS) with assisted reproductive techniques is a great challenge for the infertility specialist. Patients with PCOS demonstrate many problems, such as excessive body weight and hyperinsulinaemia, that render management more complex. Prior to treatment with IVF, the PCOS patient should be thoroughly evaluated for disclosure of endometrial neoplasia, hyperinsulinaemia, and other general health related problems. Ovarian stimulation for IVF carries the risks of overstimulation and severe hyperstimulation, which should be avoidable in most cases with preventive measures. The outcome in terms of pregnancy and implantation rates is similar for patients with PCOS when compared with patients undergoing IVF for other indications. There are some questions regarding oocyte and embryo quality in women with PCOS. This manifests itself in lower fertilization rate and decreased embryo quality in some studies. However, increased numbers of oocytes available for insemination or ICSI compensate for decreased fertilization rates and embryo quality. More recent studies suggest higher cumulative conception rates in women with PCOS when compared with controls. In-vitro maturation (IVM) of oocytes retrieved from non-stimulated or minimally stimulated cycles represents a viable option that should be considered seriously when assisted conception is attempted. Results of IVM, however, should be improved further and generalized before the technique can be advocated as the initial treatment approach in these patients.