In vitro fertilization outcome based on the detailed early luteal phase trajectory of hormones: a prospective cohort study.

BACKGROUND: Ovarian stimulation and the use of human chorionic gonadotropin (hCG) for triggering oocyte maturation in women undergoing in vitro fertilisation (IVF) introduces several differences in luteal phase hormone levels compared with natural cycles that may negatively impact on endometrial receptivity and pregnancy rates after fresh embryo transfer. Exogenous luteal phase support is given to overcome these issues. The suitability of a pragmatic approach to luteal phase support is not known due to a lack of data on early phase luteal hormone levels and their association with fertility outcomes during IVF with fresh embryo transfer. This study determined early luteal phase profiles of serum progesterone, 17-hydroxyprogesterone and hCG, and associations between hormone levels/hormone level profile after hCG trigger and the live birth rate in women undergoing IVF with fresh embryo transfer. METHODS: This prospective single center, cohort study was conducted in Vietnam from January 2021 to December 2022. Women aged 18-38 years with normal ovarian reserve and undergoing controlled ovarian stimulation using a gonadotropin-releasing hormone antagonist protocol were included. Serum hormone levels were determined before trigger, at 12, 24 and 36 h after hCG, and daily from 1 to 6 days after oocyte pick-up. Serum hormone level profiles were classified as lower or upper. The primary outcome was live birth rate based on early luteal phase hormone level profile. RESULTS: Ninety-five women were enrolled. Live birth occurred in 19/69 women (27.5%) with a lower progesterone profile and 13/22 (59.1%) with an upper progesterone profile (risk ratio [RR] 2.15; 95% confidence interval [CI] 1.28-3.60), and in 6/31 (19.4%) versus 26/60 (43.3%) with a lower versus upper serum 17-hydroxyprogesterone profile (RR 2.24; 95% CI 1.03-4.86). Nearly 20% of women had peak progesterone concentration on or before day 3 after oocyte pick-up, and this was associated with significantly lower chances of having a life birth. CONCLUSIONS: These data show the importance of proper corpus luteum function with sufficient progesterone/17-hydroxyprogesterone production for achievement of pregnancy and to maximize the chance of live birth during IVF. TRIAL REGISTRATION: NCT04693624 ( www. CLINICALTRIALS: gov ).

Assessment of a Decade of Change in U.S. Assisted Reproductive Technology Cumulative Live-Birth Rates: 2004-2009 Compared With 2014-2020.

OBJECTIVE: To assess the effects of demographic shifts, changes in contemporaneous clinical practices, and technologic innovation on assisted reproductive technology (ART) success rates by conducting an analysis of cumulative live-birth rates across different time periods, age groups, and infertility diagnoses. METHODS: We conducted a retrospective cohort study of autologous linked cycles comparing cumulative live-birth rates over successive cycles from patients undergoing their first retrieval between 2014 and 2019 in the SART CORS (Society for Assisted Reproductive Technology Clinic Outcome Reporting System) database. All cycles reported for these individuals up to 2020 were included for analysis. We compared cumulative live-birth rates stratified by age and infertility cause with published data from the 2004-2009 SART CORS database. RESULTS: From 2014 to 2019, 447,042 patients underwent their first autologous index retrieval, resulting in 1,007,374 cycles and 252,215 live births over the period of 2014 to 2020. In contrast, between 2004 and 2008, 246,740 patients underwent 471,208 cycles, resulting in 140,859 births by 2009. Noteworthy shifts in demographics were observed, with an increase in people of color seeking reproductive technology (57.9% vs 51.7%, P <.001). There was also an increase in patients with diminished ovarian reserve and ovulatory disorders and a decrease in endometriosis, tubal, and male factor infertility ( P <.001). Previously associated with decreased odds of live birth, frozen embryo transfer and preimplantation genetic testing showed increased odds in 2014-2020. Preimplantation genetic testing rose from 3.4% to 36.0% and was associated with a lower cumulative live-birth rate for those younger than age 35 years ( P <.001) but a higher cumulative live-birth rate for those aged 35 years or older ( P <.001). Comparing 2014-2020 with 2004-2009 shows that the overall cumulative live-birth rate improved for patients aged 35 years or older and for all infertility diagnoses except ovulatory disorders ( P <.001). CONCLUSION: This analysis provides insights into the changing landscape of ART treatments in the United States over the past two decades. The observed shifts in demographics, clinical practices, and technology highlight the dynamic nature of an evolving field of reproductive medicine. These findings may offer insight for clinicians to consider in counseling patients and to inform future research endeavors in the field of ART.

The impact of caesarean scar niche on fertility - a systematic review.

BACKGROUND: The trend of increasing caesarean section (CS) rates brings up questions related to subfertility. Research regarding the influence of CS on assisted reproduction techniques (ART) is conflicting. A potential mechanism behind CS-induced subfertility is intra uterine fluid resulting from a caesarean scar defect or niche. The vaginal microbiome has been repeatedly connected to negative ART outcomes, but it is unknown if the microbiome is changed in relation to a niche. METHODS: This systematic review describes literature investigating the effect of a niche on live birth rates after assisted reproduction. Furthermore, studies investigating a difference in microbial composition in subfertile persons with a niche compared to no niche are evaluated. Pubmed, Embase and Web of Science were searched on March 2023 for comparative studies on both study questions. Inclusion criteria were i.e., English language, human-only studies, availability of the full article and presence of comparative pregnancy data on a niche. The quality of the included studies and their risk of bias were assessed using the Newcastle-Ottawa scale for cohort studies. The results were graphically displayed in a forest plot. RESULTS: Six retrospective cohort studies could be included on fertility outcomes, with a total of 1083 persons with a niche and 3987 without a niche. The overall direction of effect shows a negative impact of a niche on the live birth rate (pooled aOR 0.58, 95% CI 0.48-0.69) with low-grade evidence. Three studies comparing the microbiome between persons with and without a CS could be identified. CONCLUSION: There is low-grade evidence to conclude that the presence of a niche reduces live birth rates when compared to persons without a niche. The theory that a caesarean has a negative impact on pregnancy outcomes because of dysbiosis promoted by the niche is interesting, but there is no sufficient literature about this.

The increasing number of caesarean deliveries has raised concerns about how it might affect a woman's ability to get pregnant afterwards. Some studies suggest that having a caesarean section (CS) could make it harder to conceive, particularly through in vitro fertilisation (IVF). The reason could be the scar or niche from a previous caesarean. This niche can cause fluid inside the uterus. We also know that the mix of bacteria in the vagina, called the vaginal microbiome, can affect a woman's chances of getting pregnant, especially with treatments like IVF. But we are not sure if having a caesarean affects the vaginal microbiome.To understand this better, van den Tweel's team looked at studies on whether having a niche from a caesarean affects a woman's chance of having a baby through IVF. They also looked at studies comparing the bacteria in the vagina of women who have had a caesarean with those who have not. They found that having a caesarean niche makes it harder for a woman to have a baby through IVF. However, the evidence from these studies is not very strong. We still do not know enough about whether having a caesarean niche affects the bacteria in the vagina.

Which factors affect the live birth outcome of the first single euploid frozen-thawed blastocyst transfer in couples with balanced chromosomal translocations?

Objective: The objective of this study is to investigate the factors that influence the live birth rate (LBR) of the first single euploid frozen-thawed blastocyst transfer (FBT) cycles after preimplantation genetic testing for structural rearrangements (PGT-SR) in couples with balanced chromosomal translocations (BCT). Design: Single center, retrospective and observational study. Methods: A total of 336 PGT-SR and the first single euploid FBT cycles between July 2016 and December 2022 were included in this study. The patients were divided into two groups according to the live birth outcomes. The parameters of the study population, controlled ovarian stimulation cycles, and FBT cycles were analyzed. Multivariable binary logistic regression was performed to find the factors that affected the LBR. Results: The percentage of blastocysts at developmental stage Day 5 compared to Day 6 (51.8% vs. 30.8%; P<0.001) and with morphology ≥BB compared to

Does growth hormone supplementation of in vitro fertilization/intracytoplasmic sperm injection improve cumulative live birth rates in women with poor embryonic development in the previous cycle?

BACKGROUND: Growth hormone (GH) has been proposed as an adjunct in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles, especially in women with poor ovarian response. However, it is unclear whether GH supplementation is effective in women with poor embryonic development in the previous IVF cycle. The aim of this study was to evaluate the effectiveness of GH supplementation in IVF/ICSI cycles in women with poor embryonic development in the previous cycle. METHODS: This is a retrospective cohort study from a public fertility center in China, in which we performed propensity score-matching (PSM) for female age and AFC in a ratio of 1:1. We compared the cumulative live birth rate per started cycle, as well as a series of secondary outcomes. We included 3,043 women with poor embryonic development in the previous IVF/ICSI cycle, of which 1,326 had GH as adjuvant therapy and 1,717 had not. After PSM, there were 694 women in each group. RESULTS: After PSM, multivariate analyses showed the cumulative live birth rate to be significantly higher in the GH group than the control group [N = 694, 34.7% vs. N = 694, 27.5%, risk ratio (RR): 1.4 (95%CI: 1.1-1.8)]. Endometrial thickness, number of oocytes retrieved, number of embryos available, and number of good-quality embryos were significantly higher in the GH group compared to controls. Pregnancy outcomes in terms of birth weight, gestational age, fetal sex, preterm birth rate, and type of delivery were comparable. When we evaluated the impact of GH on different categories of female age, the observed benefit in the GH group did not appear to be significant. When we assessed the effect of GH in different AFC categories, the effect of GH was strongest in women with an AFC5-6 (32.2% versus 19.5%; RR 2.0; 95% CI 1.2-3.3). CONCLUSIONS: Women with poor embryonic quality in the previous IVF/ICSI cycles have higher rates of cumulative live birth with GH supplementation.

Early GnRH-agonist therapy does not negatively impact the endometrial repair process or live birth rate.

Study objective: To investigate whether different timings of GnRH-a downregulation affected assisted reproductive outcomes in infertile women with moderate-to-severe intrauterine adhesions (IUAs) accompanied by adenomyosis. Design: A retrospective case series. Setting: An assisted reproductive technology center. Patients: The study reviewed 123 infertile women with moderate-to-severe IUAs accompanied by adenomyosis undergoing their first frozen-thawed embryo transfer (FET) cycles between January 2019 and December 2021. Measurements and main results: The majority of patients had moderate IUA (n=116, 94.31%). The average Basal uterine volume was 73.58 ± 36.50 cm3. The mean interval from operation to the first downregulation was 21.07 ± 18.02 days (range, 1-79 days). The mean duration of hormone replacement therapy (HRT) was 16.93 ± 6.29 days. The average endometrial thickness on the day before transfer was 10.83 ± 1.75 mm. A total of 70 women achieved clinical pregnancy (56.91%). Perinatal outcomes included live birth (n=47, 67.14%), early miscarriage (n=18, 25.71%), and late miscarriage (n=5, 7.14%). The time interval between uterine operation and the first downregulation was not a significant variable affecting live birth. Maternal age was the only risk factor associated with live birth (OR:0.89; 95% CI: 0.79-0.99, P=0.041). Conclusions: The earlier initiation of GnRH-a to suppress adenomyosis prior to endometrial preparation for frozen embryo transfer did not negatively impact repair of the endometrium after resection.

Maternal and obstetric outcomes following the transfer of embryos warmed with fatty acid-supplemented solutions.

BACKGROUND: Vitrification procedures decrease intracytoplasmic lipid content and impair developmental competence. Adding fatty acids (FAs) to the warming solution has been shown to recover the lipid content of the cytoplasm and improve developmental competence and pregnancy outcomes. However, the influence of the FA supplementation on live birth rates after embryo transfers and perinatal outcomes remains unknown. In the present study, we examined the influence of FA-supplemented warming solutions on live birth rates, pregnancy complications, and neonatal outcomes after single vitrified-warmed cleavage-stage embryo transfers (SVCTs). METHODS: The clinical records of 701 treatment cycles in 701 women who underwent SVCTs were retrospectively analyzed. Vitrified embryos were warmed using solutions (from April 2022 to June 2022, control group) or FA-supplemented solutions (from July 2022 to September 2022, FA group). The live birth rate, pregnancy complications, and perinatal outcomes were compared between the control and FA groups. RESULTS: The live birth rate per transfer was significantly higher in the FA group than in the control group. Multivariate logistic regression analysis further demonstrated a higher probability of live births in the FA group than in the control group. Miscarriage rates, the incidence and types of pregnancy complications, the cesarean section rate, gestational age, incidence of preterm delivery, birth length and weight, incidence of low birth weight, infant sex, and incidence of birth defects were all comparable between the control and FA groups. Multivariate logistic regression analysis further demonstrated no adverse effects of FA-supplemented warming solutions. CONCLUSIONS: FA-supplemented warming solutions improved live birth rates after SVCTs without exerting any adverse effects on maternal and obstetric outcomes. Therefore, FA-supplemented solutions can be considered safe and effective for improving clinical outcomes and reducing patient burden.

Effects of Community-Wide Teen Pregnancy Prevention Initiatives on Local Teen Birth Rates in the United States: A Synthetic Control Approach.

The impact of community-wide teen pregnancy prevention initiatives (CWIs) on local U.S. birth rates among adolescents aged 15 to 19 years was examined using synthetic control methodology within a quasi-experimental design. CWIs were implemented in 10 U.S. communities from 2010 to 2015. Each initiative implemented evidence-based teen pregnancy prevention interventions at local organizations and enhanced best practices in adolescent reproductive health care at local health centers, while engaging diverse community sectors. The synthetic control method was used to estimate the impact of each CWI on overall and race- and ethnicity-specific teen births relative to rates in synthetic control communities. Additionally, we estimated the overall effect of CWIs across communities by pooling results from the 10 synthetic control case studies using the mean percentile rank. Pooled data across all 10 communities indicated an estimated average of 6.6 fewer births per 1000 teens per year overall during the initiative relative to each community's synthetic control (p = .001). By race and ethnicity, there were an estimated average of 6.4 fewer births per 1000 teens per year among Black teens (p = .03), 10.7 fewer births among Hispanic teens (p = .03), and 4.2 fewer births (p = .10) among White teens. Results from individual communities indicated an intervention effect on overall and/or race/ethnicity-specific teen birth rates in five communities. This study demonstrates the value of synthetic control methods in evaluating community-level outcomes of programmatic efforts. Findings indicate the CWIs had a positive impact on teen birth rates and have the potential to address racial and ethnic disparities in those rates.

Long-term population projections: Scenarios of low or rebounding fertility.

The size of the human population is projected to peak in the 21st century. But quantitative projections past 2100 are rare, and none quantify the possibility of a rebound from low fertility to replacement-level fertility. Moreover, the most recent long-term deterministic projections were published a decade ago; since then there has been further global fertility decline. Here we provide updated long-term cohort-component population projections and extend the set of scenarios in the literature to include scenarios in which future fertility (a) stays below replacement or (b) recovers and increases. We also characterize old-age dependency ratios. We show that any stable, long-run size of the world population would persistently depend on when an increase towards replacement fertility begins. Without such an increase, the 400-year span when more than 2 billion people were alive would be a brief spike in history. Indeed, four-fifths of all births-past, present, and future-would have already happened.

When everyone's doing it: The relative effects of geographical context and social determinants of health on teen birth rates.

Geographic disparities in teen birth rates in the U.S. persist, despite overall reductions over the last two decades. Research suggests these disparities might be driven by spatial variations in social determinants of health (SDOH). An alternative view is that "place" or "geographical context" affects teen birth rates so that they would remain uneven across the U.S. even if all SDOH were constant. We use multiscale geographically weighted regression (MGWR) to quantify the relative effects of geographical context, independent of SDOH, on county-level teen birth rates across the U.S. Findings indicate that even if all counties had identical compositions with respect to SDOH, strong geographic disparities in teen birth rates would still persist. Additionally, local parameter estimates show the relationships between several components of SDOH and teen birth rates vary over space in both direction and magnitude, confirming that global regression techniques commonly employed to examine these relationships likely obscure meaningful contextual differences in these relationships. Findings from this analysis suggest that reducing geographic disparities in teen birth rates will require not only ameliorating differences in SDOH across counties but also combating community norms that contribute to high rates of teen birth, particularly in the southern U.S. Further, the results suggest that if geographical context is not incorporated into models of SDOH, the effects of such determinants may be interpreted incorrectly.

Midluteal serum estradiol levels are associated with live birth rates in hormone replacement therapy frozen embryo transfer cycles: a cohort study.

OBJECTIVE: To study whether midluteal serum estradiol (E2) levels are associated with the live birth rate in hormone replacement therapy frozen embryo transfer (HRT-FET) cycles in patients with optimal midluteal serum progesterone (P4) levels. DESIGN: Observational prospective cohort study. SETTING: Public fertility clinic. PATIENTS: A total of 412 women had an HRT-FET cycle single blastocyst transfer from January 2020 to November 2022. INTERVENTION: The HRT-FET cycle priming regimen included oral E2 (6mg/24 h) administered in the evening, followed by vaginal P4 (400mg/12 h). Serum E2 and P4 levels were measured using a standardized method, 2-4 hours after the latest P4 administration and 9-14 hours after E4 administration on the day of blastocyst transfer, day 6 of P4 administration. Patients with serum P4 levels (<11 ng/mL [35 nmol/L]) on the day of transfer received additional rectal P4 (400mg/12 h). No additional E2 dose was administered. MAIN OUTCOME MEASURES: The primary outcome was the live birth rate (LBR) in relation to E2 levels at blastocyst transfer day. RESULTS: The optimal serum E2 levels correlating with ongoing pregnancy were ≥292 pg/mL and <409 pg/mL (≥1,070 pmol/L and <1,500 pmol/L). The LBR was 59% (60/102) when E2 levels were within this range, whereas a significantly lower LBR of 39% (101/260) was seen in patients when E2 levels were <292 pg/mL (<1,070 pmol/L) and of 28% (14/50) when E2 levels were ≥409 pg/mL (≥1,500 pg/mL). In a logistic regression analysis, adjusting for serum P4 level ≥11 ng/mL or <11 ng/mL (≥35 nmol or <35 nmol/L) on the day of transfer, body mass index, age at oocyte retrieval, day 5 or 6 vitrified blastocysts, and blastocyst score, the adjusted risk difference of live birth was -0.21 (-0.32; -0.10) when the E2 level was <292 pg/mL (<1,070 pmol/L) and -0.31 (-0.45; -0.18) when the E2 level was ≥409 pg/mL (≥1,500 pmol/L) compared with E2 levels ≥292 pg/mL and <409 pg/mL (≥1,070 and <1,500 pmol/L). Importantly, only 25% of patents had optimal levels. CONCLUSION: The study shows a significant association between serum E2 levels and reproductive outcomes in an HRT-FET cohort in which optimal serum P4 levels were secured. Midluteal serum E2 levels are associated with the LBR in HRT-FET cycles, and E2 levels should neither be too high nor too low. CLINICAL TRIAL REGISTRATION NUMBER: EudraCT No.: 2019-001539-29.

Births: Final Data for 2022.

Objectives- This report presents 2022 data on U.S. births by selected characteristics. Trends in fertility patterns and maternal and infant characteristics are described. Methods-Descriptive tabulations based on birth certificates of the 3.67 million births registered in 2022 are shown by maternal age, live-birth order, race and Hispanic origin, marital status, tobacco use, prenatal care, source of payment for the delivery, method of delivery, gestational age, birthweight, and plurality. Selected data by mother's state of residence and birth rates also are shown. Trends for 2010 to 2022 are presented for selected items, and by race and Hispanic origin for 2016-2022. Results-A total of 3,667,758 births occurred in the United States in 2022, essentially unchanged from 2021. The general fertility rate declined 1% from 2021 to 56.0 births per 1,000 females ages 15-44 in 2022. The birth rate for females ages 15-19 declined 2% from 2021 to 2022; birth rates fell 7% for women ages 20-24, rose 1% to 5% for women ages 25-29 and 35-44, and rose 12% for women ages 45-49 (the first increase since 2016). The total fertility rate declined less than 1% to 1,656.5 births per 1,000 women in 2022. Birth rates declined for unmarried women but increased for married women from 2021 to 2022. Prenatal care beginning in the first trimester declined to 77.0% in 2022; the percentage of women who smoked during pregnancy declined to 3.7%. The cesarean delivery rate was unchanged in 2022 (32.1%); Medicaid was the source of payment for 41.3% of births. The preterm birth rate declined 1% to 10.38%; the low birthweight rate rose 1% to 8.60%. The twin birth rate was unchanged in 2022 (31.2 per 1,000 births); the 2% decrease in the triplet and higher-order multiple birth rate.

Impact of thyroid autoimmunity on the cumulative live birth rates after IVF/ICSI treatment cycles.

BACKGROUND: Cumulative live birth rate (CLBR) is considered as the most important endpoint for assessing the probability of having a baby in a complete in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment cycle. Many previous studies have focused on the association between thyroid autoimmunity (TAI) and live birth rate after first embryo transfer cycle, however, evidence on whether the presence of TAI affects the CLBR is lacking. The purpose of this study is to investigate the impact of TAI on the CLBR in a complete IVF/ICSI cycle. METHODS: This retrospective study included 12,796 women who underwent their first IVF/ICSI treatment between January 2019 and February 2021. Based on the levels of thyroid antibodies, 2,603 women were assigned to the TAI group, and 10,193 women were assigned to the control group. Subgroup analysis was performed according to the different causes of infertility (including male factor only, ovulation disorder, tubal factor, endometriosis and unexplained infertility) and different types and titres of thyroid antibodies. The primary outcome in this study was CLBR, which included live births from the fresh embryo transfer cycle and all subsequent frozen-thawed embryo transfer cycles performed before December 2021. RESULTS: There was no significant difference in the CLBR between the TAI and control groups, even after adjusting for relevant confounders including age, body mass index, cause of infertility, thyroid function, protocols of controlled ovarian stimulation, type of transfer (fresh vs. frozen), type of transferred embryo (cleavage-stage embryo vs. blastocyst), and fertilization method (IVF vs. ICSI) (cumulative live birth: 50.6% vs. 52.1%, OR 0.94, 95% CI 0.86-1.02, adjusted OR 0.97, 95%CI 0.89-1.06). Subgroup analysis showed that no significant difference was observed in CLBR between the TAI and control groups for all causes of infertility, except for infertility attributed to endometriosis. Among women with endometriosis, the CLBR was significantly lower in the TAI group than that in the control group; however, this difference was not significant after adjusting for potential confounders including age, body mass index, thyroid function, protocols of controlled ovarian stimulation, type of transfer (fresh vs. frozen), type of transferred embryo (cleavage-stage embryo vs. blastocyst), and fertilization method (IVF vs. ICSI) (cumulative live births: 43.1% vs. 51.0%, OR 0.73, 95% CI 0.53-0.99, adjusted OR 0.74, 95% CI 0.53-1.02). Another subgroup analysis demonstrated that the type and titre of thyroid antibody did not affect CLBR in women with TAI. CONCLUSIONS: In our study, there was no significant difference in the CLBR between women with TAI and those without TAI, which suggests that TAI did not affect the chances of having a baby in a complete IVF/ICSI treatment cycle.

Sociodemographic factors underlying lifetime fertility among ever-married Swazi women.

Fertility rates remain high in certain subgroups of the population, and there is limited research about the sociodemographic factors influencing fertility, particularly in Eswatini where women are often considered minors. This study aims to investigate the changes in lifetime fertility, and the associations between sociodemographic factors and lifetime fertility among ever-married women. The study used secondary cross-sectional data from the 2010 and 2014 Eswatini Multiple Indicator Cluster Surveys (MICS), with a sample size of 2,295 and 2,351 women, respectively. The data was analysed using descriptive statistics and multivariable Poisson regression. The results showed that fertility rates decreased from 3.47 to 3.21 children between 2010 and 2014. The study found that child loss and age (25+ years) were significant factors associated with higher fertility, while delayed age at marriage and sexual debut (20+ years), at least secondary education, and being rich were strong predictors of lower fertility rates. The study recommends creating awareness about and strengthening laws to abolish early sexual debut and marriage. It also suggests empowering women through education, encouraging the use of contraceptives, and providing maternal and child health services in rural areas where fertility rates tend to be higher.

Les taux de fécondité restent élevés dans certains sous-groupes de la population, et les recherches sur les facteurs sociodémographiques influençant la fécondité sont limitées, en particulier à Eswatini où les femmes sont souvent considérées comme mineures. Cette étude vise à étudier les changements dans la fécondité au cours de la vie et les associations entre les facteurs sociodémographiques et la fécondité au cours de la vie chez les femmes déjà mariées. L'étude a utilisé des données transversales secondaires des enquêtes par grappes à indicateurs multiples (MICS) d'Eswatini de 2010 et 2014, avec un échantillon de 2 295 et 2 351 femmes, respectivement. Les données ont été analysées à l'aide de statistiques descriptives et d'une régression de Poisson multivariée. Les résultats ont montré que les taux de fécondité ont diminué de 3,47 à 3,21 enfants entre 2010 et 2014. L'étude a révélé que la perte d'enfants et l'âge (25 ans et plus) étaient des facteurs importants associés à une fécondité plus élevée, tandis qu'un âge plus tardif au mariage et aux débuts sexuels (20 ans et plus) ), au moins une éducation secondaire, et le fait d'être riche étaient de puissants prédicteurs de taux de fécondité plus faibles. L'étude recommande de sensibiliser et de renforcer les lois visant à abolir les premiers rapports sexuels et le mariage précoces. Il suggère également d'autonomiser les femmes grâce à l'éducation, d'encourager l'utilisation de contraceptifs et de fournir des services de santé maternelle et infantile dans les zones rurales où les taux de fécondité ont tendance à être plus élevés.

Fertility and self-rated health of migrant women of childbearing age-an analysis of moderating effects based on socioeconomic status.

BACKGROUND: As fertility rates continue to decline and negative population growth emerges, China has sequentially introduced encouraging fertility policies to raise fertility levels. The impact of fertility on women's health remains inconclusive. It is essential to explore further the correlation between fertility and the health status of 113 million migrant women of childbearing age in China. OBJECTIVE: To investigate how fertility affects the health status of migrant women of childbearing age and determine if migrant women's socioeconomic status plays a moderating role in this process. METHODS: Using a nationally representative dataset from the 2018 China Migrants Dynamic Survey (CMDS), we examined the effects of fertility on the self-rated health of migrant women of childbearing age. An ordinary least squares regression model with moderating effects was used for the empirical study, and robustness tests were conducted based on the ordered probit model and propensity score matching to address endogeneity. RESULTS: The empirical results indicated that a rise in the number of children born significantly reduces the self-rated health of migrant women of childbearing age. An increase in years of schooling and household income can significantly mitigate the negative impact of childbearing on the health of migrant women. The robustness of the above results was validated through alternative models and propensity score matching (PSM) methods. The heterogeneity analysis revealed that fertility exerts a negative impact on the health status of migrant women with rural household registration and on the health status of inter-provincial and inter-city migrant women. Further investigation found that the occurrence of childbirth during migration and an increase in the number of girls significantly negatively impacted the health status of migrant women. In contrast, the increase in the number of boys did not show a significant effect. Improving the health of migrant women of childbearing age significantly positively impacted their future childbearing intentions. CONCLUSIONS: Migrant women of childbearing age bear the dual burden of migration and childbirth. Our findings showed the rise in the number of children born and the occurrence of childbirth during migration posed greater challenges to the health status of female migrants, particularly among those with lower socioeconomic status. Government and community efforts for enhancing health among migrant women of childbearing age are recommended.

Age-related increase in live-birth rates of first frozen thaw embryo versus first fresh transfer in initial assisted reproductive technology cycles without PGT.

BACKGROUND: The landscape of assisted reproductive technology (ART) has seen a significant shift towards frozen-thawed embryo transfers (FET) over fresh transfers, driven by technological advancements and clinical considerations. This study aimed to compare live birth outcomes between primary FET and fresh transfers, focusing on cycles without preimplantation genetic testing (PGT), using United States national data from the SART CORS database spanning from 2014 to 2020. METHODS: We performed a retrospective cohort study of autologous first ART cycles without PGT comparing primary embryo transfer (frozen thaw vs. fresh) success rates from the 2014-2020 SARTCORS database. Live-birth rates (LBR) and cumulative live-birth rates (CLBR) were compared between first FET versus first fresh embryo transfer from an index retrieval. Multivariate logistic regression (MLR) determined association between live birth outcomes and method of transfer. In a subsequent sub-analysis, we compared these two embryo transfer methods among patients with either diminished ovarian reserve (DOR) or male factor infertility. RESULTS: 228,171 first ART cycles resulted in primary embryo transfer. 62,100 initial FETs and 166,071 fresh transfers were compared. Initial FETs demonstrated higher LBR and CLBR compared to fresh transfers (LBR 48.3% vs. 39.8%, p < 0.001; CLBR 74.0% vs. 60.0%, p < 0.0001). MLR indicated greater chances of live birth with FET across all age groups, with adjusted odds ratio (aOR) of live-birth incrementally increasing with advancing age groups. For DOR cycles, LBR and CLBR were significantly higher for FET compared to fresh (33.9% vs. 26.0%, p < 0.001, 44.5% vs. 37.6%, p < 0.0001), respectively. MF cycles also demonstrated higher LBR and CLBR with FET (52.3% vs. 44.2%, p < 0.001, 81.2% vs. 68.9%, p < 0.0001), respectively. MLR demonstrated that in DOR cycles, initial FET was associated with greater chance of live birth in age groups ≥ 35yo (p < 0.01), with aOR of live birth increasingly considerably for those > 42yo (aOR 2.63, p < 0.0001). CONCLUSIONS: Overall LBR and CLBR were greater for first FET than fresh transfers with incremental increases in odds of live birth with advancing age, suggesting the presence of a more favorable age-related change in endometrial receptivity present in frozen-thawed cycles. For both DOR and MF cycles, LBR and CLBR after primary transfer were greater for first FET than fresh. However, this was particularly evident in older ages for DOR cycles. This suggests that supraphysiologic stimulation in older DOR cycles may be detrimental to endometrial receptivity, which is in part corrected for in FET cycles.

A reassessment of trends and rural-urban/regional differences in the total fertility rate in China, 2000-2020: analyses of the 2020 national census data.

The decline in the total fertility rate (TFR) is a key driver of population change and has important implications for population health and social development. However, China's TFR has been a considerable controversy due to a lack of high-quality data. Therefore, this study used the 2020 national population census of China (NPCC) data and reverse survival method to reassess temporal trends in the TFRs and to reexamine rural-urban differences and regional variations in TFRs from 2000 to 2020 in China. Overall, there were significant gaps between the estimated and reported TFRs before 2020, and the estimated TFRs based on the 2020 NPCC data remained higher than the reported TFRs from government statistics. Although TFRs rebounded shortly in the years after the two-child policy, they have shown a wavelike decline since 2010. Additionally, the estimated TFRs fluctuated below 1.5 children per woman in urban areas compared to above 1.8 in rural areas, but the rural-urban differences continued to decrease. Regarding geographic regional variations, the estimated TFRs in all regions displayed a declining trend during 2010-2020, especially in rural areas. Large decreases of over 25% in TFRs occurred in the north, east, central, and northwest regions. In addition to changing the birth policy, the government and society should adopt comprehensive strategies, including reducing the costs of marriage, childbearing, and child education, as well as promoting work-family balance, to encourage and increase fertility levels.

Comparison of pregnancy outcomes among patients of different ages who underwent frozen-thawed high-quality single blastocyst transfer.

OBJECTIVE: To investigate the feasibility of performing frozen-thawed high-quality single blastocyst transfer in women of different ages. METHODS: A total of 1,279 women were divided into four groups: a 38-40-year-old group (n = 147), 35-37-year-old group (n = 164), 30-34-year-old group (n = 483), and < 30-year-old group (n = 485). Intergroup comparisons of baseline characteristics and pregnancy and neonatal outcomes were made. RESULTS: The clinical pregnancy rate (47.6%), and live birth rate (34.0%) in the 38-40-year-old group were significantly lower than those in the 30-34-year-old group (64.4%, 50.9%, respectively; all P < 0.001) and < 30-year-old group (62.9%, 50.7%, respectively; all P < 0.001). However, the 35-37-year-old group did not differ from the other three groups in these two dimensions (all P > 0.05). Moreover, there were no differences in the rates of biochemical pregnancy, miscarriage, or obstetric or neonatal complications among the four groups (all P > 0.05). According to the multivariate logistic regression analysis, the 35-37-year-old group was not associated with non-live birth outcomes, adverse pregnancy outcomes, or obstetric or neonatal complications. However, being 38-40 years of age was a risk factor for non-live birth (OR = 2.121, 95% CI: 1.233-3.647) and adverse pregnancy outcomes (OR = 1.630, 95% CI: 1.010-2.633). Post hoc power analysis showed that the study was sufficiently powered to detect meaningful differences. CONCLUSION: Frozen-thawed high-quality single blastocyst transfer produces the same satisfactory pregnancy outcomes for women aged 35-37 years as younger patients. Future prospective randomized controlled studies with larger populations are needed to verify the feasibility and safety of this method.

Effect of Day 3 cell number on the live birth rate of vitrified-warmed Day 5 single blastocyst transfer in young women.

BACKGROUND: Previous studies have reported inconsistent results regarding blastocyst selection with a high day 3 (D3) cell number and the eventual pregnancy outcomes. Thus, in this study, the relationship between the D3 cell number and clinical outcomes of day 5 single blastocyst transfer (SBT) in vitrified-warmed transfer cycles was investigated. METHODS: Our retrospective study included 1144 day 5 SBT in vitrified-warmed cycles between February 2016 and February 2021. All cycles were the first vitrified-warmed cycles, and the female patients were less than 35 years of age. Based on the D3 cell number, the cycles were divided into four groups, as follows: group A (3-7 cells, n = 130); group B (8-9 cells, n = 621); group C (10-12 cells, n = 328); and group D (13-16 cells, n = 65). The differences in the live birth rate (LBR), clinical pregnancy rate, and miscarriage rate were examined among the four groups. RESULTS: The LBR and clinical pregnancy rate increased with the D3 cell number (P < 0.01). No significant difference was found in the miscarriage rate among the groups (P = 0.055). After adjusting for confounding factors, the LBR was significantly higher in groups C (odds ratio [OR] = 1.477, 95% confidence interval [CI]: 1.124-1.941, P = 0.005) and D (OR = 2.000, 95% CI: 1.166-3.429, P = 0.012) than in group B. CONCLUSIONS: A high D3 cell number (> 9 cells) was associated with a high LBR in the vitrified-warmed day 5 SBT cycles of patients < 35 years of age. The cell number of D3 embryos can be an important reference indicator for blastocyst selection. Among blastocysts with the same morphological score, those with > 9 cells on D3 can be preferentially selected for transplantation.