Can the physical act of sexual intercourse before frozen embryo transfer improve IVF treatment outcome? A Randomized Clinical Trial

Abstract Background Exposure of the female reproductive tract to either seminal plasma or fluid component of the ejaculate is beneficial to achieving successful embryo implantation and normal embryo development. But whether the "physical" component of of sexual intercourse during the peri-transfer period have any influence on FET pregnancy outcome is not clear. Methods We conducted a randomized trial that included 223 patients undergoing IVF treatment at a University-affiliated reproductive center from 19 July 2018 to 24 February 2019. Enrolled patients undergoing IVF treatment were randomized either to engage sexual intercourse using the barrier contraception (Group A, n = 116) or to abstain (Group B, n = 107) one night before FET. The follow-up parameters included biochemical losses rate, clinical pregnancy, early abortion and implantation rate. Results Patients having intercourse had higher clinical pregnancy rate (51.72% vs. 37.07%, P = 0.045) and implantation rate (38.31% vs. 24.77%, P  = 0.005) compared to those did not engage intercourse. However, there was no significant difference of the spontaneous abortion rate between two groups (11.67% 33 vs. 14.63%, P  = 0.662). Conclusions Sexual intercourse before the day of embryo transfer may improve the clinical pregnancy and implantation rates during the frozen- thawed embryo transfer (FET) cycle. However, it should be noted that patients choose only one time for sexual intercourse, that is, the night before embryo transfer. TRIAL REGISTRATION NUMBER: This study was registered at the China Clinical Trial Registration Center, with the registration number ChiCTR1800017209.