Effect of Endometrial Biopsy on in Vitro Fertilization Pregnancy Rates - a Multicenter Study

Overview

Animal and clinical studies have suggested that local tissue trauma can promote the process of an embryo implanting in the uterine cavity. The clinical studies have been performed in patients with a history of previously failed treatments using in vitro fertilization; a process of stimulating many eggs from a women and removing them from the body, to allow fertilisation with sperm to occur in a laboratory setting. The embryos are then replaced into the uterine cavity. This study questions whether endometrial biopsy (placing a small straw like catheter through the cervix and into the uterine cavity to take a sample of tissue via suction into the bore of the catheter), within 5-10 days of starting a cycle of in vitro fertilization, will improve pregnancy outcome for patients in the first or second cycle of treatment. The hypothesis is that endometrial biopsy will improve pregnancy outcome. The study is a randomized multicentre study involving 3 Canadian fertility centres.

Although the data are preliminary, there are studies suggesting that mild endometrial trauma in the cycle preceding IVF increases pregnancy rates, at least in women with recurrent implantation failure. Whether endometrial biopsy could promote implantation and improve pregnancy rates in the larger population of women undergoing IVF has yet to be explored. The present study will address this question and examine the impact of endometrial biopsies on IVF outcomes in the context of a randomized controlled trial. The optimal timing of the endometrial biopsy in the cycle preceding IVF has not been determined, but the majority of the studies have included a biopsy in the mid-luteal phase of the preceding cycle. In order to allow an adjuvant therapy to IVF that would be considered tolerable to a subject, and applicable to a large infertile women population, it was determined that a single endometrial biopsy, performed approximately 1 week prior to the start of controlled ovarian hyperstimulation (COH) in an IVF cycle, would be the simplest, most flexible, and generalizable intervention to study its effects on pregnancy rates. All other components of the IVF treatment will remain constant with approximately 8-12 days of ovarian stimulation, human chorionic gonadotrophin (HCG) trigger being administered in that time frame and oocyte retrieval occuring 36 hours later from trigger. The embryo transfer will take place either day 3 or day 5 after oocyte retrieval.