Implantation, the act of the embryo adhering to the lining of the uterus or endometrium, is an essential part of a normal pregnancy. Implantation failure remains a major factor limiting the success of in vitro fertilization (IVF) cycles. As implantation depends on the cross talk between the embryo and the endometrium considerable research has been dedicated to understanding and optimizing this exchange.
Local injury to the endometrium in the form of an endometrial biopsy or “scratch test” has been proposed to improve implantation and most importantly live birth rates. Initial studies in patients with recurrent miscarriage showed improvement in implantation rates after endometrial biopsies were performed at different time points of the menstrual cycle. After that, multiple studies have been performed on women with recurrent miscarriages and the majority have demonstrated significant improvement in live birth rates following an endometrial biopsy performed in the preceding cycle.
However, these studies did not use the same methods or patient populations and most recently a well designed clinical study from Hong Kong reported no benefit in live birth rate for women undergoing a “scratch test”. Thus controversy exists in our field as to what degree of endometrial injury is required for beneficial outcome, the number of injuries to be performed (one, two or more), at what day or phase of the menstrual cycle the procedure must be performed, or even which patients would most benefit from a scratch test.
Given the incongruity of the data, WUSM Fertility and Reproductive Medicine Center doctors and researchers are conducting the “Scratch Test Study” to clarify if endometrial mechanical stimulation in the form of an endometrial biopsy prior to embryo transfer increases clinical pregnancy and live birth rates in our patient population. This research will allow us to better serve our patients and contribute to the medical literature as a whole.
Women 18 years of age or older who are undergoing fresh and/or frozen embryo transfer with normal uterine cavity are eligible to participate. Participants will be randomized to receiving a timed endometrial biopsy or a “sham” endometrial biopsy according to their cycle. Participants and their physicians will be blinded to whether they received a biopsy to adhere to strict research protocol and cycle outcomes such as pregnancy rate will be determined. All patients are encouraged to participate and help us answer this exciting medical conundrum: does endometrial injury prior to IVF improve pregnancy outcome.
by Dr Maureen Schulte, MD