Study on the optimal time limit of frozen embryo transfer and the effect of a long-term frozen embryo on pregnancy outcome.

In this retrospective study conducted at Sichuan Jinxin Xinan Women and Children's Hospital spanning January 2015 to December 2021, our objective was to investigate the impact of embryo cryopreservation duration on outcomes in frozen embryo transfer. Participants, totaling 47,006 cycles, were classified into 3 groups based on cryopreservation duration: ≤1 year (Group 1), 1 to 6 years (Group 2), and ≥6 years (Group 3). Employing various statistical analyses, including 1-way ANOVA, Kruskal-Wallis test, chi-square test, and a generalized estimating equation model, we rigorously adjusted for confounding factors. Primary outcomes encompassed clinical pregnancy rate and Live Birth Rate (LBR), while secondary outcomes included biochemical pregnancy rate, multiple pregnancy rate, ectopic pregnancy rate, early and late miscarriage rates, preterm birth rate, neonatal birth weight, weeks at birth, and newborn sex. Patient distribution across cryopreservation duration groups was as follows: Group 1 (40,461 cycles), Group 2 (6337 cycles), and Group 3 (208 cycles). Postcontrolling for confounding factors, Group 1 exhibited a decreased likelihood of achieving biochemical pregnancy rate, clinical pregnancy rate, and LBR (OR < 1, aOR < 1, P < .05). Furthermore, an elevated incidence of ectopic pregnancy was observed (OR > 1, aOR > 1), notably significant after 6 years of freezing time [aOR = 4.141, 95% confidence intervals (1.013-16.921), P = .05]. Cryopreservation exceeding 1 year was associated with an increased risk of early miscarriage and preterm birth (OR > 1, aOR > 1). No statistically significant differences were observed in birth weight or sex between groups. However, male infant birth rates were consistently higher than those of female infants across all groups. In conclusion, favorable pregnancy outcomes align with embryo cryopreservation durations within 1 year, while freezing for more than 1 year may diminish clinical pregnancy and LBRs, concurrently elevating the risk of ectopic pregnancy and preterm birth.

The association of post-embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study.

BACKGROUND: The influence of SARS-CoV-2 infection after embryo transfer on early pregnancy outcomes in in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies. OBJECTIVE: This study aimed to investigate the association between SARS-CoV-2 infection within 10 weeks after embryo transfer and early pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. STUDY DESIGN: This prospective cohort study was conducted at a single public in vitro fertilization center in China. Female patients aged 20 to 39 years, with a body mass index ranging from 18 to 30 kg/m2, undergoing in vitro fertilization/intracytoplasmic sperm injection treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks after embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study used single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes. RESULTS: A total of 857 female patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days after embryo transfer did not have a significant negative association with the biochemical pregnancy rate (adjusted odds ratio, 0.74; 95% confidence interval, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days after embryo transfer had no significant association with the implantation rate (36.6% in infected vs 44.0% in uninfected group; P=.181). No statistically significant association was found with the clinical pregnancy rate after adjusting for confounding factors (adjusted odds ratio, 0.69; 95% confidence interval, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks after embryo transfer had no significant association with the early miscarriage rate (adjusted odds ratio, 0.77; 95% confidence interval, 0.35-1.71). CONCLUSION: Our study suggests that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. It is important to note that these findings are specific to the target population of in vitro fertilization/intracytoplasmic sperm injection patients aged 20 to 39 years, without previous SARS-CoV-2 infection, and with a body mass index of 18 to 30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.

Young obese patients may benefit from GnRH-a long protocol contributing to higher implantation rate and live birth rate of fresh IVF-ET cycles.

Introduction: Obesity has detrimental influences on women reproductive health. There is little experience in optimizing controlled ovarian hyperstimulation (COH) protocols to treat Chinese obese patients who are undergoing in vitro fertilization and embryo transfer (IVF-ET) therapy. Methods: The clinical outcome differences were retrospectively analyzed among obese patients who received gonadotrophin-releasing hormone agonist (GnRH-a), GnRH antagonist (GnRH-ant), micro dose GnRH-a (mGnRH-a) and GnRH-a long protocol in IVF-ET cycle at Chengdu Jinjiang Hospital for Women's and Children's Health from January 2014 to December 2019. Results: The transplantation rate of the GnRH-a long protocol group (59.1%) was higher than that of the GnRH-ant (25.9%) and mGnRH-a (36.7%) groups. The total live birth rate of the GnRH-a long protocol group (46.2%) was higher than that of the GnRH-a group (25.9%) and GnRH-ant group (40.3%). The total number of frozen embryos in the GnRH-ant group was higher than in the other groups (P < 0.05). After adjusting for confounding factors, the logistic regression analysis showed that the GnRH-a long protocol group had higher probabilities of biochemical pregnancy, clinical pregnancy, and live birth than the GnRH-a protocol group. The Gn dose in the mGnRH-a group was higher than the other three groups. Whether single or twin, there were similar neonatal outcomes among the four groups including premature birth rate, Apgar score, newborn weight, and length. Conclusion: For young obese patients undergoing IVF-ET, the GnRH-a long protocol for COH gives better pregnancy outcomes.

Maternal Hepatitis B Virus Infection and Pregnancy Outcomes of Freeze-Thaw Embryo Transfer.

This cohort study assesses the association of maternal hepatitis B virus (HBV) serostatus with pregnancy outcomes in women undergoing freeze-thaw embryo transfer (FET).

Effect of serum progesterone on human chorionic gonadotropin trigger day / metaphase II oocyte ratio on pregnancy and neonatal outcomes in women undergoing ICSI cycle.

BACKGROUND: The serum progesterone on human chorionic gonadotropin trigger day / metaphase II oocyte (P/MII) ratio might be a more predictable indicator of pregnancy and neonatal outcomes as compare to P/estradiol (E2) or P alone. Hence, we conducted a larger population study to compare the pregnancy and neonatal outcomes in the low and high P/MII ratio. METHODS: A retrospective, single-center, larger population cohort study between January 2015 and August 2021. Calculate the threshold effect of P/MII ratio on clinical pregnancy rate according to the construct smooth curve fitting. Divide data into two groups by threshold for comparison. RESULTS: 3566 fresh ICSI-ET cycles were included, in which 929 singleton delivery and 676 twin deliveries. Compare to P/MII ≤ 0.367 group, it indicated that the P/MII > 0.367 group had a lower clinical pregnancy rate and live birth rate, furthermore, a significantly higher rate of LBW and SGA were observed in the singleton and twin deliveries. No deleterious impact of high P/MII ratio on embryo quality and undesirable pregnancy outcomes was shown. CONCLUSIONS: When P/MII is higher than 0.367, may have adverse impacts on pregnancy and neonatal outcomes for ICSI cycle.

Effects of sequential cleavage and blastocyst embryo transfer on pregnancy outcomes in patients with poor ovarian response.

The management of patients with poor ovarian response (POR) remains a major challenge for fertility specialists in in vitro fertilization-embryo transfer (IVF-ET). In this retrospective cohort study, we aimed to evaluate the clinical effect of sequential transfer on pregnancy outcomes in patients with POR. A total of 3579 POR patients who underwent the first frozen embryo transfer (FET) cycle were enrolled from January 2018 to April 2021. The patients were divided into three groups according to the embryo transfer (ET) strategy adopted: a study group that included POR patients in whom a cleavage-stage embryo (day 3) and a blastocyst (day 5/6) were transferred (sequential transfer group), and two control groups in whom two cleavage-stage embryos (D3-dET group) or two blastocysts (D5/6-dET group) were transferred. The study group was matched with the control groups at a ratio of 1:4 by propensity score matching (PSM). The main pregnancy outcomes measured were the live birth rate and multiple pregnancy rate. After PSM, the live birth rate in the sequential transfer group was significantly higher than that in the D3-dET group (44.2% vs. 34.3%, P = 0.019), and was similar to that in the D5/6-dET group (44.2% vs. 45.3%; P = 0.90). In addition, there was no increase in the risk of multiple pregnancy among POR patients undergoing sequential transfer compared with both D3-dET (26.7% vs. 25.6%, P = 0.85) and D5/6-dET (26.7% vs. 28.4%, P = 0.97) groups. These findings imply that sequential transfer is an effective option for POR patients and could be utilized after careful consideration.

An Individualized Recommendation for Controlled Ovary Stimulation Protocol in Women Who Received the GnRH Agonist Long-Acting Protocol or the GnRH Antagonist Protocol: A Retrospective Cohort Study.

Background: The GnRH agonist long-acting protocol and GnRH antagonist protocol are widely used in ovarian stimulation. Which protocol eliciting higher live birth rate for IVF/ICSI patients with different ages, different ovarian reserves and different body mass index (BMI) has not been studied. However, among these protocols, the one that elicits higher live birth in IVF/ICSI patients with different ages, ovarian reserves and body mass indexes (BMI) has not been identified. Methods: This was a retrospective cohort study about 8579 women who underwent the first IVF-ET from January, 2018 to August, 2021. Propensity Score Matching (PSM) was used to improve the comparability between two protocols. Results: After PSM, significant higher live birth rates were found in the GnRH agonist long-acting protocol compared to GnRH antagonist protocol (44.04% vs. 38.32%) (p<0.001). Stratified analysis showed that for those with AMH levels between 3 ng/ml and 6 ng/ml, with BMI ≥ 24 kg/m2 and were aged ≥ 30 years old, and for those women with BMI < 24kg/m2 and were aged ≥30 years whose AMH levels were ≤ 3ng/ml, the GnRH agonist long-acting protocol was more likely to elicit live births [OR (95%CI), 2.13(1.19,3.80)], [OR (95%CI), 1.41(1.05,1.91)]. However, among women with BMI ≥ 24kg/m2 and were aged ≥30 years whose AMH levels were ≤ 3ng/ml, the GnRH agonist long-acting protocol had a lower possibility of eliciting live births [OR (95%CI), 0.54(0.32,0.90)]. Also, among women with AMH levels between 3 ng/ml and 6 ng/ml, with BMI ≥ 24 kg/m2 and with age < 30 years and for those with AMH levels between 3 ng/ml and 6 ng/ml, regardless of age, and with BMI<24kg/m2,, the possibility of live births was similar between the two protocols [OR (95%CI), 1.06(0.60,1.89)], [OR (95%CI), 1.38(0.97,1.97)], [OR (95%CI), 0.99(0.72,1.37)]. Among the women with AMH levels ≤ 3 ng/ml and with were aged < 30years, regardless of BMI, the possibility of live birth was similar between the two protocols [OR (95%CI), 1.02(0.68,1.54)], [OR (95%CI), 1.43(0.68,2.98)]. Moreover, among women with AMH levels ≥ 6ng/ml, the possibility of live birth was similar between the two protocols [OR (95%CI),1.42(0.75,2.69)], [OR (95%CI),1.02(0.19,5.35)], [OR (95%CI), 1.68(0.81,3.51)], [OR (95%CI), 0.51(0.10,2.55)]. Conclusions: The suitability of the GnRH agonist long-acting protocol or GnRH antagonist protocol to infertility patients is dependent on specific biological characteristics of the patients.

Effect of artificial cycle with or without GnRH-a pretreatment on pregnancy and neonatal outcomes in women with PCOS after frozen embryo transfer: a propensity score matching study.

BACKGROUND: In frozen embryo transfer (FET), there is limited consensus on the best means of endometrial preparation in terms of the reproductive outcomes in women with polycystic ovary syndrome (PCOS). The present study aimed to compare the pregnancy and neonatal outcomes following artificial cycle FET (AC-FET) with or without gonadotropin-releasing hormone agonist (GnRH-a) pretreatment among women with PCOS. METHODS: A total of 4503 FET cycles that satisfied the inclusion criteria were enrolled in this retrospective cohort study between 2015 and 2020. The GnRH-a group received GnRH-a pretreatment while the AC-FET group did not. Propensity score matching (PSM) method and multivariate logistic regression analysis were performed to adjust for potential confounding factors. RESULTS: After PSM, women in the GnRH-a group suffered a significantly lower miscarriage rate (11.2% vs. 17.1%, P = 0.033) and a higher live birth rate (LBR) compared with those in the AC-FET group (63.1% vs. 56.8%, P = 0.043). No differences were observed in the rates of biochemical pregnancy, clinical pregnancy and ectopic pregnancy between the two groups. A higher mean gestational age at birth was observed in the GnRH-a group than in the AC-FET group (39.80 ± 2.01 vs. 38.17 ± 2.13, P = 0.009). The incidence of neonatal preterm birth (PTB) in the GnRH-a group was lower than that in the AC-FET group (7.4% vs. 14.9%, P = 0.009). Singleton newborns conceived after GnRH-a group were more likely to be small for gestational age (SGA) than those born after AC-FET group (16.4% vs. 6.8%, P = 0.009). However, no significant differences were found between the two groups in terms of mean birthweight, apgar score, the rates of macrosomia, large for gestational age and low birth weight. CONCLUSION(S): In women with PCOS who underwent AC-FET, GnRH-a pretreatment was significantly associated with a higher live birth rate and a reduced risk of neonatal PTB. However, there was a concomitant increase in the risk of developing SGA babies.

Baseline psychological stress and ovarian norepinephrine levels negatively affect the outcome of in vitro fertilisation.

OBJECTIVE: We determined the effect of baseline psychological stress and norepinephrine (NE) levels in the follicular fluid on the outcome of in vitro fertilisation (IVF). METHODS: One hundred seven women with tubal factor infertility were evaluated before and during their first IVF treatment. On the first day of down-regulation, their psychological state was measured using the Zung Self-rating Anxiety (SAS) and Depression Scales (SDS), and defined as baseline psychological stress. On oocyte retrieval day, NE levels in the follicular fluid and peripheral plasma were measured by high-performance liquid chromatography. RESULTS: On the first day of down-regulation, nearly 10% of the women with tubal factor infertility reported that they were experiencing both anxiety and depression. This baseline psychological stress was lower in pregnant (3.7%) than in non-pregnant women (15.7%, p<0.05). On oocyte retrieval day, the NE levels in follicular fluid were almost twice the amount seen in peripheral plasma, but did not differ in pregnant and non-pregnant women (p>0.05). NE levels in follicular fluid were negatively associated with the percentage of good quality embryos (r= -0.62, p<0.05). CONCLUSIONS: Baseline psychological stress (both anxiety and depression) may negatively influence the clinical pregnancy rate of IVF treatment in women with tubal factor infertility. Furthermore, follicular NE levels are negatively associated with the percentage of good quality embryos.