RESUMEN
BACKGROUND: The diagnostic criteria and phenotypes in polycystic ovary syndrome are heterogeneous. Currently, it is unclear how to assess a patient's prognosis based on the onset time of menstruation disturbance. Evidence on this topic is scarce and has mainly focused on menstrual patterns. OBJECTIVE: This study aimed to assess the association between the onset time of menstrual disturbance and clinical features and in vitro fertilization pregnancy outcomes in patients with polycystic ovary syndrome. STUDY DESIGN: Our study was a secondary analysis of data collected as part of a randomized controlled trial conducted to compare live birth rates between fresh embryo transfer and frozen embryo transfer in 1508 individuals with polycystic ovary syndrome. Here, 1500 participants were classified into 2 groups according to the onset time of menstrual disturbance: immediately after menarche (early group) and after at least 1 year of regular menstruation (late group). We compared the prepregnancy clinical features, variables of ovarian stimulation, pregnancy outcomes after the initial cycle of embryo transfer, and perinatal and neonatal complications in the 2 groups. RESULTS: Compared with the late group, the early group had more antral follicles (32.00 [range, 27.25-39.50] vs 28.00 [range, 24.00-36.00]; P<.001), an elevated level of antimüllerian hormone (7.02 ng/mL [range, 3.60-11.47] vs 5.66 ng/mL [range, 3.65-8.92]; P=.024), a higher level of baseline luteinizing hormone (10.01±5.93 vs 8.51±5.53 IU/l; P<.001) and luteinizing hormone-to-follicle-stimulating hormone ratio (1.51 [range, 1.00-2.32] vs 1.45 [range, 0.92-2.13]; P<.001), lower levels of fasting glucose (5.47 mmol/L [range, 5.11-5.73] vs 5.50 mmol/L [range, 5.17-5.76]; P<.001), and insulin at 2 hours after 75-g oral glucose tolerance test (56.85 µU/mL [range, 34.63-94.54] vs 59.82 µU/mL [range, 33.56-94.67]; P=.027), a higher level of high-density lipoprotein (1.26 mmol/L [range, 1.04-1.37] vs 1.21 mmol/L [range, 1.07-1.45]; P=.006). During in vitro fertilization, the early group had a higher level of peak estradiol (4596.50 pg/mL [range, 2639.25-6321.00] vs 3954.00 pg/mL [range, 2378.75-6113.50]; P=.013), and luteinizing hormone (2.52 IU/L [range, 1.40-4.21] vs 1.93 IU/L [range, 0.91-3.32]; P=.010) on the day of human chorionic gonadotropin trigger. There was no statistically significant difference observed in the number of oocytes and embryos, the rates of pregnancy and live birth, and the risks of obstetrical and neonatal between the 2 groups. CONCLUSION: An early onset of menstrual disturbance in patients with polycystic ovary syndrome may be associated with slightly more severe reproductive features and slightly milder metabolic features. Nonetheless, the outcomes of in vitro fertilization and the initial cycle of embryo transfer were comparable between the 2 groups.
RESUMEN
BACKGROUND: Frozen embryo transfer resulted in a higher birthweight and an increased risk of macrosomia than fresh embryo transfer. However, the mechanism was still unclear. When the impact of frozen embryo transfer on fetal growth began was unknown. Crown-rump length at 11-13 weeks had been regarded as a good indicator of fetal growth in the first trimester and had been used for gestational age calculation in women with uncertain last menstrual periods. OBJECTIVE: To evaluate the association between frozen embryo transfer and early fetal growth, particularly the crown-rump length, then fresh embryo transfer. The secondary objective was to investigate the potential correlation between crown-rump length and birthweight. STUDY DESIGN: This was a retrospective cohort study conducted at the Reproductive Medical Center of Shandong University. A total of 4949 patients who obtained singleton pregnancy after frozen embryo transfer and 1793 patients who got singleton pregnancy after fresh embryo transfer between January 1, 2017 and December 31, 2022 were included. The primary outcome was the crown-rump length measured via ultrasound at 11-13 weeks gestation. The secondary outcomes were perinatal outcomes, including birthweight and the risk of large for gestational age, small for gestational age, macrosomia, low birthweight, and premature delivery. Multivariable linear regression models were used to adjust for potential confounders of crown-rump length. RESULTS: A total of 6742 live singleton births after frozen embryo transfer or fresh embryo transfer were included in this study. In the univariable analysis, the frozen embryo transfer group had a larger crown-rump length (5.75±0.53 cm vs 5.57±0.48 cm, P<.001) and an increased risk of larger-than-expected crown-rump length (13.5% vs11.2%, P=.013) than the fresh embryo transfer group. After adjusting for confounders in multivariable linear regression models, frozen embryo transfer was still associated with a larger crown-rump length (regression coefficient, 3.809 [95% confidence intervals, 3.621-3.997], P<.001). When subgrouped by fetal gender, the crown-rump length of the frozen embryo transfer group was larger than the fresh embryo transfer group in both male and female fetuses. In addition, the crown-rump length was consistently larger in the frozen embryo transfer group than the fresh embryo transfer group in subgroups of the peak estradiol levels. The comparisons among different crown-rump length groups showed that smaller-than-expected crown-rump length was associated with increased risks of small for gestational age (6.3% vs 3.0%, P<.001) and preterm delivery (9.6% vs 6.7%, P=.004) than normal crown-rump length. CONCLUSION: Frozen embryo transfer was associated with a larger crown-rump length than fresh embryo transfer, suggesting that the effect of frozen embryo transfer on fetal growth may begin in the early trimester. Suboptimal fetal growth in the first trimester may be associated with low birthweight and premature delivery.
RESUMEN
Importance: The optimal interpregnancy interval (IPI) after a clinical pregnancy loss (CPL) remains controversial. Few studies have addressed the role of the IPI after a preceding CPL during in vitro fertilization (IVF) treatment. Objective: To evaluate the association between different IPI lengths after a preceding CPL and pregnancy outcomes of the next frozen embryo transfer (FET). Design, Setting, and Participants: This retrospective cohort study was conducted using data from the Center for Reproductive Medicine of Shandong University in China. The study included women who underwent frozen-thawed blastocyst transfer between July 1, 2017, and June 30, 2022, within 1 year after a preceding CPL during IVF treatment. Follow-up for pregnancy outcomes was completed for all participants on March 31, 2023. Data analysis was performed from April to May 2023. Exposures: Interpregnancy interval length was classified as less than 3 months, 3 to less than 6 months, or 6 to 12 months. Main Outcomes and Measures: Outcomes included live birth, conception, clinical pregnancy, pregnancy loss, preterm birth, small or large for gestational age, and low birth weight. Multivariable logistic regression analysis was conducted to evaluate the association between IPI and pregnancy outcomes by adjusted odds ratios (AORs). Results: This study included 2433 women (mean [SD] age, 31.8 [4.6] years) who received IVF treatment. There were 338 women (13.9%) with an IPI of less than 3 months, 1347 (55.4%) with an IPI of 3 to less than 6 months, and 748 (30.7%) with an IPI of 6 to 12 months. The median (IQR) IPI lengths for the 3 groups were 77 (65-85), 128 (109-152), and 234 (202-288) days, respectively. Compared with an IPI of 6 to 12 months, shorter IPIs (<3 and 3 to <6 months) were associated with decreased odds of clinical pregnancy (AOR, 0.70 [95% CI, 0.53-0.92] and 0.79 [0.65-0.95]), live birth (AOR, 0.64 [95% CI, 0.48-0.85] and 0.74 [0.61-0.90]), and healthy live birth (AOR, 0.63 [95% CI, 0.46-0.87] and 0.79 [0.64-0.98]). Compared with women with an IPI of 6 to 12 months, women with shorter IPIs (<3 and 3 to <6 months) had a higher risk of total pregnancy loss (AOR, 1.87 [95% CI, 1.31-2.67] and 1.29 [1.00-1.66], respectively). Conclusions and Relevance: The results of this study suggest that delaying the next FET for at least 6 months after a preceding CPL was associated with beneficial pregnancy outcomes, considering that a decreased likelihood of achieving clinical pregnancy and live birth was observed among women with shorter IPIs. Further prospective studies are needed to confirm these findings.
