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Benagiano G, Mancuso S, Guo SW, Di Renzo GC. Events Leading to the Establishment of Pregnancy and Placental Formation: The Need to Fine-Tune the Nomenclature on Pregnancy and Gestation. Int J Mol Sci 2023; 24:15420. [PMID: 37895099 PMCID: PMC10607313 DOI: 10.3390/ijms242015420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
Today, there is strong and diversified evidence that in humans at least 50% of early embryos do not proceed beyond the pre-implantation period. This evidence comes from clinical investigations, demography, epidemiology, embryology, immunology, and molecular biology. The purpose of this article is to highlight the steps leading to the establishment of pregnancy and placenta formation. These early events document the existence of a clear distinction between embryonic losses during the first two weeks after conception and those occurring during the subsequent months. This review attempts to highlight the nature of the maternal-embryonic dialogue and the major mechanisms active during the pre-implantation period aimed at "selecting" embryos with the ability to proceed to the formation of the placenta and therefore to the completion of pregnancy. This intense molecular cross-talk between the early embryo and the endometrium starts even before the blastocyst reaches the uterine cavity, substantially initiating and conditioning the process of implantation and the formation of the placenta. Today, several factors involved in this dialogue have been identified, although the best-known and overall, the most important, still remains Chorionic Gonadotrophin, indispensable during the first 8 to 10 weeks after fertilization. In addition, there are other substances acting during the first days following fertilization, the Early Pregnancy Factor, believed to be involved in the suppression of the maternal response, thereby allowing the continued viability of the early embryo. The Pre-Implantation Factor, secreted between 2 and 4 days after fertilization. This linear peptide molecule exhibits a self-protective and antitoxic action, is present in maternal blood as early as 7 days after conception, and is absent in the presence of non-viable embryos. The Embryo-Derived Platelet-activating Factor, produced and released by embryos of all mammalian species studied seems to have a role in the ligand-mediated trophic support of the early embryo. The implantation process is also guided by signals from cells in the decidualized endometrium. Various types of cells are involved, among them epithelial, stromal, and trophoblastic, producing a number of cellular molecules, such as cytokines, chemokines, growth factors, and adhesion molecules. Immune cells are also involved, mainly uterine natural killer cells, macrophages, and T cells. In conclusion, events taking place during the first two weeks after fertilization determine whether pregnancy can proceed and therefore whether placenta's formation can proceed. These events represent the scientific basis for a clear distinction between the first two weeks following fertilization and the rest of gestation. For this reason, we propose that a new nomenclature be adopted specifically separating the two periods. In other words, the period from fertilization and birth should be named "gestation", whereas that from the completion of the process of implantation leading to the formation of the placenta, and birth should be named "pregnancy".
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Affiliation(s)
- Giuseppe Benagiano
- Faculty of Medicine and Surgery, Sapienza University of Rome, 00185 Rome, Italy;
- Geneva Foundation for Medical Education and Research, 1206 Geneva, Switzerland
| | - Salvatore Mancuso
- Faculty of Medicine and Surgery, Catholic University of the Sacred Heart, 00168 Rome, Italy;
| | - Sun-Wei Guo
- Research Institute, Shanghai Obstetrics & Gynecology Hospital, Fudan University, Shanghai 200011, China;
| | - Gian Carlo Di Renzo
- Center for Perinatal and Reproductive Medicine, University of Perugia, 06156 Perugia, Italy
- Department of Obstetrics, Gynecology and Perinatology, I.M. Sechenov First Moscow State Medical University, 119146 Moscow, Russia
- Department of Obstetrics & Gynecology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Zhao J, Xuan Y, Zhang Y, Hong X, Zhang H, Zhang R, Yan T, Wang Y, Peng Z, Zhang Y, Jiao K, He T, Wang Q, Shen H, Zhang Y, Yan D, Wang B, Ma X. Assessment of Prior Infection With Hepatitis B Virus and Fecundability in Couples Planning Pregnancy. JAMA Netw Open 2023; 6:e2330870. [PMID: 37651142 PMCID: PMC10472190 DOI: 10.1001/jamanetworkopen.2023.30870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/19/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE The association of hepatitis B virus (HBV) infection with reduced fecundability among reproductive-aged couples lacks large-population, in-depth study evidence. OBJECTIVE To investigate the association of HBV infection with time to pregnancy in couples planning pregnancy, and to explore whether this association varied by gravidity, health statuses, or lifestyles. DESIGN, SETTING, AND PARTICIPANTS This is a population-based cohort study of Chinese couples participating in the National Free Preconception Check-up Projects during 2015 to 2017. They were planning pregnancy and were followed-up every 3 months until getting pregnant, as confirmed by gynecologic ultrasonography, or were followed-up for 1 year. Data were analyzed between March 1, 2022, and September 30, 2022. MAIN OUTCOMES AND MEASURES The main outcome was time to pregnancy, assessed using fecundability hazard ratios (HRs). The Cox proportional hazards regression models were used to estimate the association of HBV infection with fecundability. RESULTS Among 2 419 848 couples (mean [SD] age, 27.87 [5.20] years for women and 29.58 [5.50] years for men), 126 728 women (5.24%) and 156 572 men (6.47%) were infected with HBV. Compared with the HBV-negative group, the fecundability of both women and men in the HBV-positive group decreased by 5% (HR, 0.95; 95% CI, 0.94-0.95). Compared with couples in which both partners were HBV negative, the fecundability of those in which both partners were HBV positive declined by 6% (HR, 0.94; 95% CI, 0.93-0.96) among all couples, by 3% (HR, 0.97; 95% CI, 0.95-0.99) among nulligravidas couples, and by 7% (HR, 0.93; 95% CI, 0.91-0.95) among multigravidas couples. Both the female-male and couple models suggested that the association of HBV infection with decreased fecundability was more pronounced in couples with multigravidas. The negative association was greater in people with overweight and obesity and was inconsistent in certain subgroups; in particular, it was more pronounced in women with reproductive tract infections, normal fasting plasma glucose, and no alcohol intake and in men with normal blood pressure. CONCLUSIONS AND RELEVANCE In this population-based cohort study, HBV infection was associated with decreased fecundability in a general reproductive-aged population, especially in couples with multigravidas. For women and men with certain health statuses and lifestyles, a comprehensive consideration of this association is recommended to provide personalized fertility guidance.
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Affiliation(s)
- Jun Zhao
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Yan Xuan
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Yue Zhang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Xiang Hong
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Hongguang Zhang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Rong Zhang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Tao Yan
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Yuanyuan Wang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Zuoqi Peng
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Ya Zhang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Kailei Jiao
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Tianyu He
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
| | - Qiaomei Wang
- Department of Maternal and Child Health, National Health Commission of the People’s Republic of China, Beijing, China
| | - Haiping Shen
- Department of Maternal and Child Health, National Health Commission of the People’s Republic of China, Beijing, China
| | - Yiping Zhang
- Department of Maternal and Child Health, National Health Commission of the People’s Republic of China, Beijing, China
| | - Donghai Yan
- Department of Maternal and Child Health, National Health Commission of the People’s Republic of China, Beijing, China
| | - Bei Wang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Epidemiology and Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu, China
| | - Xu Ma
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Center, Beijing, China
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Loy SL, Ku CW, Tiong MMY, Ng CST, Cheung YB, Godfrey KM, Lim SX, Colega MT, Lai JS, Chong YS, Shek LPC, Tan KH, Chan SY, Chong MFF, Yap F, Chan JKY. Modifiable Risk Factor Score and Fecundability in a Preconception Cohort in Singapore. JAMA Netw Open 2023; 6:e2255001. [PMID: 36749588 PMCID: PMC10408273 DOI: 10.1001/jamanetworkopen.2022.55001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 12/15/2022] [Indexed: 02/08/2023] Open
Abstract
IMPORTANCE Although multiple modifiable risk factors have been identified for reduced fecundability (defined as lower probability of conception within a menstrual cycle), no scoring system has been established to systematically evaluate fecundability among females who are attempting to conceive. OBJECTIVE To examine the association of a risk score based on 6 modifiable factors with fecundability, and to estimate the percentage reduction in incidence of nonconception if all study participants achieved a minimal risk score level. DESIGN, SETTING, AND PARTICIPANTS This population-based cohort study obtained data from the S-PRESTO (Singapore Preconception Study of Long-Term Maternal and Child Outcomes) prospective cohort study. Females of reproductive age who were trying to conceive were enrolled from February 2015 to October 2017 and followed for 1 year, ending in November 2018. Data were analyzed from March to May 2022. EXPOSURES A reduced fecundability risk score was derived by giving participants 1 point for each of the following factors: unhealthy body mass index, unhealthy diet, smoking, alcohol intake, folic acid supplement nonuser, and older maternal age. Total scores ranged from 0 to 6 and were classified into 5 levels: level 1 (score of 0 or 1), level 2 (score of 2), level 3 (score of 3), level 4 (score of 4), and level 5 (score of 5 or 6). MAIN OUTCOMES AND MEASURES Fecundability, measured by time to conception in cycles, was analyzed using discrete-time proportional hazards models with confounder adjustment. RESULTS A total of 937 females (mean [SD] age, 30.8 [3.8] years) were included, among whom 401 (42.8%) spontaneously conceived within 1 year of attempting conception; the median (IQR) number of cycles before conception was 4 (2-7). Compared with participants with a level 1 risk score, those with level 2, 3, 4, and 5 risk scores had reductions in fecundability of 31% (adjusted fecundability ratio [FR], 0.69; 95% CI, 0.54-0.88), 41% (FR, 0.59; 95% CI, 0.45-0.78), 54% (FR, 0.46; 95% CI, 0.31-0.69) and 77% (FR, 0.23; 95% CI, 0.07-0.73), respectively. Assessment of the population attributable fraction showed that all participants achieving a minimal (level 1) risk level would be associated with a reduction of 34% (95% CI, 30%-39%) in nonconception within a year. CONCLUSIONS AND RELEVANCE Results of this study revealed the co-occurrence of multiple modifiable risk factors for lowered fecundability and a substantially higher conception rate among participants with no or minimal risk factors. The risk assessment scoring system proposed is a simple and potentially useful public health tool for mitigating risks and guiding those who are trying to conceive.
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Affiliation(s)
- See Ling Loy
- Department of Reproductive Medicine, KK Women’s and Children’s Hospital, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | - Chee Wai Ku
- Department of Reproductive Medicine, KK Women’s and Children’s Hospital, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | | | - Carissa Shi Tong Ng
- Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
| | - Yin Bun Cheung
- Program in Health Services and Systems Research and Center for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore
- Tampere Center for Child, Adolescent and Maternal Health Research, Tampere University, Tampere, Finland
| | - Keith M. Godfrey
- Medical Research Council Lifecourse Epidemiology Centre, University of Southampton, Southampton, United Kingdom
- National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom
| | - Shan Xuan Lim
- Saw Swee Hock School of Public Health, National University of Singapore, National University Health System, Singapore, Singapore
| | - Marjorelee T. Colega
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Jun Shi Lai
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Yap-Seng Chong
- Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Lynette Pei-Chi Shek
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
- Khoo Teck Puat-National University Children’s Medical Institute, National University Hospital, National University Health System, Singapore, Singapore
| | - Kok Hian Tan
- Duke-NUS Medical School, Singapore, Singapore
- Department of Maternal Fetal Medicine, KK Women’s and Children’s Hospital, Singapore, Singapore
| | - Shiao-Yng Chan
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
| | - Mary Foong-Fong Chong
- Saw Swee Hock School of Public Health, National University of Singapore, National University Health System, Singapore, Singapore
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Fabian Yap
- Duke-NUS Medical School, Singapore, Singapore
- Department of Paediatrics, KK Women’s and Children’s Hospital, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jerry Kok Yen Chan
- Department of Reproductive Medicine, KK Women’s and Children’s Hospital, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
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Konishi S, Mizuno Y. Pre-Conceptional Anti-Thyroid Antibodies and Thyroid Function in Association with Natural Conception Rates. Int J Environ Res Public Health 2022; 19:13177. [PMID: 36293757 PMCID: PMC9603695 DOI: 10.3390/ijerph192013177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Thyroid functioning is an integral part of the endocrine system that supports conception and pregnancy. Frequent consumption of seafood and iodine by Japanese people may adversely affect their thyroid function. Thus, in this study, we aimed to analyze the associations between iodine intake, thyroid hormones, autoimmunity, and natural conception rates in Japanese women trying to conceive their first child. A prospective study of 24 weeks targeted 80 women with no history of infertility, who did not plan to undergo fertility treatment. Concentrations of urinary iodine concentration and thyroid biomarkers in the serum at enrollment were measured. Thirty-five women naturally conceived during the follow-up. The median (inter-quartile range) urinary concentration of iodine was 297 (165, 500) μg/L. Free triiodothyronine (T3) and free thyroxin (T4) negatively correlated with urinary iodine concentrations. Women with anti-thyroid peroxidase (anti-TPO) ≥ 16 IU/mL had lower conception rates (hazard ratio: 0.28, 95% confidence interval, 0.08-0.92) compared with those with anti-TPO < 16 IU/mL, after adjusting for age and coital frequency. None of anti-thyroglobulin antibody, free T3, free T4, or thyroid-stimulating hormone showed significant associations with conception rate after adjusting for age and coital frequency. The negative association between thyroid autoimmunity and natural conception rates warrants further investigation.
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