Comparison of fresh versus frozen embryo transfer in women with polycystic ovary syndrome

Abstract

Introduction: Transfer of fresh embryos is a usual practice but in women at risk of ovarian hyperstimulation due to excess follicle development, elective cryopreservation of all embryos followed by transfer in subsequent cycle is preferred. Fresh cycles have supraphysiological steroid levels which may alter the endometrial receptivity and probably affect placentation adversely whereas frozen embryo transfer is performed to the uterus after a programmed physiologic cycle of hormone replacement to prepare the endometrium. Objective: To find out whether frozen embryo transfer in subsequent cycle is better than that in fresh transfer in women with polycystic ovary syndrome (PCOS) when human chorionic gonadotropin (hCG) is used as a trigger in antagonist cycles. Study Design, Size, Duration: It is a prospective cohort study. Infertile women Participants/Materials, Setting, Methods: Women (N = 126) with terminal estradiol levels below 2500 pg/ml were triggered with recombinant hCG, and based on the number of retrieved oocytes, they were divided into two groups: Group A 15 oocytes were retrieved, but all embryos were frozen on day 3 and transferred in subsequent cycle. Primary outcomes were clinical pregnancy rates and live birth rates. Secondary outcomes were fertilization, implantation and miscarriage rates. Results: Group A had 73 fresh transfer, and Group B had 53 frozen embryo transfer. Both groups were comparable regarding age, body mass index, basal follicular stimulating hormone, antimullerian hormone and antral follicle count. Categorical data were represented as frequency and percentages, differences in these measures between the groups were compared using chi-square tests, and quantitative data were analyzed by using student t test. Clinical pregnancy rates (Group A: 38.4% versus Group B: 41.5%, P = 0.88) and live birth rate (Group A: 26.0% versus Group B: 33.9%, P = 0.25) were slightly higher in Group B though not statistically significant. The miscarriage rate in both the groups was comparable (Group A: 15.1% and Group B: 15.1%, P = 0.8).