Menstrual abnormalities effects on clinical features and in vitro fertilization pregnancy outcomes in women with polycystic ovarian syndrome

The diagnostic criteria and phenotypes in polycystic ovary syndrome (PCOS) 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. To assess the association between the onset time of menstrual disturbance and clinical features and in-vitro fertilization (IVF) pregnancy outcomes in patients with polycystic ovary syndrome. Our study was a secondary analysis of data collected as part of a randomized controlled trial conducted to compare live birth rates between fresh and frozen embryo transfer in 1508 individuals with PCOS. In this study, 1,500 participants were classified into two groups according to the onset time of menstrual disturbance: immediately after menarche (Group Early) and after at least one year of regular menstruation (Group Late). We compared the pre-pregnancy clinical features, variables of ovarian stimulation, pregnancy outcomes after the initial cycle of embryo transfer, and perinatal and neonatal complications in the two groups. Compared with the Group Late, the Group Early had more antral follicles (32 [27.25,39.5] vs. 28 [24,36], P<0.001), an elevated level of anti-Müllerian hormone (7.02 [3.60,11.47] vs. 5.66 [3.65,8.92]ng/ml, P=0.024), a higher level of baseline luteinizing hormone (LH, 10.01 ± 5.93 vs. 8.51 ± 5.53 IU/l, P<0.001) and LH/follicle-stimulating hormone ratio (1.51 [1.00,2.32] vs. 1.45 [0.92,2.13], P<0.001), lower levels of fasting glucose (5.47 [5.11,5.73] vs. 5.50 [5.17,5.76] mmol/l, P<0.001) and insulin at 2 hours after 75 g oral glucose tolerance test (56.85 [34.63,94.54] vs. 59.82 [33.56,94.67] µU/ml, P=0.027), a higher level of high-density lipoprotein (1.26 [1.04,1.37] vs. 1.21 [1.07,1.45] mmol/l, P=0.006). During IVF, the Group Early had a higher level of peak estradiol (4596.5 [2639.25,6321] vs. 3954 [2378.75, 6113.5] pg/ml, P=0.013) and LH (2.52 [1.40,4.21] vs. 1.93 [0.91, 3.32] IU/L, P=0.010) on the day of human chorionic gonadotropin (hCG) trigger. No statistically significant differences in the number of oocytes and embryos, the rates of pregnancy and live birth, and the risks of obstetric and neonatal complications were observed between the two groups. An early onset of menstrual disturbance in patients with polycystic ovary syndrome may be associated with slightly severer reproductive features and slightly milder metabolic features. Nonetheless, the outcomes of IVF and the initial cycle of embryo transfer were comparable between the two groups.