The Effect of Delivery Method on Subsequent Frozen Embryo Transfer Success [ID 1368]

INTRODUCTION: The increasing prevalence of cesarean deliveries (CDs) has raised questions regarding their implications for future fertility for those undergoing frozen embryo transfers (FETs). This study investigates the correlation between mode of delivery and subsequent FET. METHODS: This retrospective study included 316 FET cycles of patients with a prior successful FET pregnancy who had returned for a subsequent transfer of a single euploid embryo. Patients were divided into two groups based on their previous mode of delivery, CD (n=144) versus spontaneous vaginal delivery (SVD) (n=172). Independent t-tests were used to compare patient characteristics. Chemical pregnancy rates, clinical intrauterine gestation (CIG), and fetal cardiac activity (FCA) were analyzed using chi-squared analysis. Z-proportional tests were employed to evaluate biochemical loss rates. A significance level of P <.05 was established for statistical significance. RESULTS: The average age at the time of subsequent FET was similar between groups (CD: 35.14±3.93 years; SVD: 34.74±3.88 years; P =.364); however, body mass index was significantly higher in the CD group compared to the SVD group (29.01±6.75 versus 26.61±6.05, P <.001). The rate of chemical pregnancies (71% versus 77%, P =.188), FCA (56% versus 59%, P =.571), CIG (59% versus 63%, P =.43), and biochemical losses (17% versus 24%, P =.78) were not statistically different. CONCLUSIONS/IMPLICATIONS: Future pregnancy outcomes did not significantly differ between women who delivered via CD compared to SVD, suggesting prior mode of delivery does not adversely affect subsequent FET success.