Abstract

Background: In-Vitro Fertilization (IVF) treatment involves synchronization of multiple time-sensitive events, most of which are rate-limiting too. Controlled ovarian stimulation (COS) is one such event. The reproductive outcomes based on the duration of COS (d-COS) in a fresh, IVF embryo transfer (ET) are not well established and therefore, remains largely uncertain.

Objective: To evaluate the association between d-COS and live birth rate (LBR) in women undergoing a fresh IVF-ET using autologous oocytes.

Methods: A retrospective cohort study was conducted using a US nationwide IVF register – SARTCORS (Society for Assisted Reproductive Technology Clinic Outcomes Reporting System). From a total of 93,889 cycles, we included 56,666 fresh, autologous, IVF - ET treatment cycles from January 2014 through December 2015, with follow-up until October 2016. Adjusted odds and risk ratio with 95% confidence intervals were estimated while controlling for multiple demographic factors and other potential confounders.

Variables and outcomes: The primary exposure variable was d-COS defined as the difference in days between gonadotrophin administration and oocyte retrieval. The primary outcome measure was live birth following a fresh IVF-ET. Secondary outcome measures included biochemical pregnancy rate, miscarriage rate, implantation rate and clinical pregnancy rate.

Results: A total of 56,666 treatment cycles (mean [SD] age of 33.9 [4.47], BMI of 26.1 [6.02], AMH value of 2.19 [3.37]), and a baseline FSH value of 7.62 [3.49]) underwent a fresh IVF-ET. The LBR after a combined analysis for all ages and all protocols was 44.2 % (n = 25043). In the combined analysis, there was a statistically significant decrease in the live birth rate with LBR with d-COS beyond 10 days. The adjusted OR (95% CI) of LBR for a woman who had 11, 12, 13 and ≥14 days of COS, compared to optimal duration of 10 days was 0.97 (0.87-0.99), 0.94 (0.8-1), 0.83 (0.77-0.89) and 0.73 (0.68-0.79) respectively. The AOR (95% CI) of miscarriage rates for a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 1.12 (1-1.26), 0.99 (0.87-1.12), 1.03 (0.90 -1.17) and 1.04 (0.90 - 1.2) respectively. With increasing d-COS, the implantation rate (IR) and clinical pregnancy rate (CPR) also showed a decreasing trend, as with other reproductive outcomes. The RR (95% CI) for implantation rate in a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 0.97 (0.93-1), 0.97 (0.93-1.01), 0.91 (0.87-0.95) and 0.86 (0.82-0.9). The adjusted OR (95% CI) of CPR for a woman who had 11, 12, 13 and ≥14 days of COS, compared to referent was 0.95 (0.89-1.01), 0.93 (0.87-0.99), 0.8 (0.75-0.86) and 0.7 (0.65-0.75) respectively.

Conclusions and Relevance: In this nationwide cohort study of women undergoing fresh IVF-ET using autologous oocytes, controlled ovarian stimulation lasting approximately 10-days was associated with an optimal live birth rate.

Keywords: In Vitro Fertilization, embryo transfer, duration of controlled ovarian stimulation, SART CORS

How to Cite: Eapen A, Summers K, Matteson C, Raff MR, Ten Eyck P, Sparks AET, Duran EH.Association between duration of controlled ovarian stimulation and live birth rate in women undergoing In Vitro Fertilization: a SART CORS analysis. Proc Obstet Gynecol. 2022;11(2): Article 3 [ 26 p.]. Available from: https://pubs.lib.uiowa.edu Free full text article.