IntroductionThe choice of trigger drug for the controlled ovarian hyperstimulation (COH) protocol correlates with the outcome of in vitro fertilization/intracytoplasmic sperm injection embryo transfer (IVF/ICSI-ET). The co-administration of gonadotropin releasing hormone agonist (GnRH-a) and human chorionic gonadotropin (hCG), i.e., dual trigger, for final oocyte maturation, has received much attention in recent years. This trial was designed to determine whether a dual trigger approach by lengthening the time between trigger and ovum pick-up (OPU) improves the quantity and quality of mature oocytes/top-quality embryos and pregnancy outcomes in expected normal responders with a high immature oocyte rate.Methods and AnalysisWe propose a study at the Affiliated Hospital of Shandong University of Chinese Medicine. A total of 90 individuals undergoing COH use a fixed GnRH antagonist protocol. They will be assigned randomly into two groups according to the trigger method and timing: recombinant hCG (6500 IU) will be injected only 36 hours before OPU for final oocyte maturation (hCG-only trigger); co-administration of GnRH-a and hCG for final oocyte maturation, 40 and 34 hours prior to OPU, respectively (Dual trigger). The primary outcome is metaphase-II (MII) oocytes rate. Secondary outcomes are number of oocytes retrieved, fertilization rate, top-quality embryos rate, blastula formation rate, embryo implantation rate, clinical pregnancy rate, miscarriage rate, live birth rate, cumulative pregnancy/live birth rates, and ovarian hyperstimulation syndrome (OHSS) rate.Ethics and DisseminationThe reproductive ethics committee of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine certified this study (Identifier: SDUTCM/2021.7.26) as ethical. All individuals will sign written informed consent. All data and biological samples will be protected according to law. The results of this study will be disseminated in a peer-reviewed scientific journal.Clinical Trial Registration[chictr.gov.cn], identifier [ChiCTR2100049292].

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 sexual intercourse during the peri-transfer period have any influence on frozen-thawed embryo transfer (FET) pregnancy outcomes is not clear. Methods: We conducted a randomized trial that included 223 patients undergoing in vitro fertilization (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 primary outcome was clinical pregnancy 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 embryo transfer may improve the clinical pregnancy and implantation rates during FET cycles. However, it should be noted that patients choose only one time for sexual intercourse, that is, the night before embryo transfer. Trial registration: The present study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/, ChiCTR1800017209).

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 sexual intercourse during the peri-transfer period have any influence on frozen-thawed embryo transfer (FET) pregnancy outcomes is not clear. Methods We conducted a randomized trial that included 223 patients undergoing in vitro fertilization (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 primary outcome was clinical pregnancy 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 embryo transfer may improve the clinical pregnancy and implantation rates during FET cycles. However, it should be noted that patients choose only one time for sexual intercourse, that is, the night before embryo transfer. Trial registration The present study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/, ChiCTR1800017209).