Local injury to the endometrium on the day of oocyte retrieval has a negative impact on implantation in assisted reproductive cycles: a randomized controlled trial. Does local endometrial injury in the nontransfer cycle improve the IVF-ET outcome in the subsequent cycle in patients with previous unsuccessful IVF? A randomized controlled pilot study. A prospective randomized study: day 2 versus day 5 embryo transfer.
To evaluate the effect of local injury to the endometrium on the day of oocyte retrieval on implantation and pregnancy rates in assisted reproductive cycles.
                In a prospective controlled trial, a total of 156 patients, <38 years old, in their first in vitro fertilization (IVF) cycle were randomized. In 77 patients, two small endometrial samples from anterior and posterior walls of uterus were obtained with a Novak curette on the day of oocyte retrieval and in 79 patients no intervention was performed.
                The experimental and control patients were matched regarding women's age, body mass index, basal FSH, duration and etiology of infertility, treatment protocol, number of retrieved oocyte, endometrial thickness, percentage of intracytoplasmic sperm injection performance, fertilization rate, the percentage of patients with good and top quality embryos, and the number of embryos transferred. The implantation rate (7.9 vs. 22.9%), clinical (12.3 vs. 32.9%; odds ratio = 0.25; 95% confidence interval = 0.12-0.66; p < 0.05) and ongoing pregnancy (9.6 vs. 29.1%; odds ratio = 0.25; 95% confidence interval = 0.10-0.64; p < 0.05) rates were significantly lower in experimental group, compared with 79 controls.
                According to the results of this study, local injury to the endometrium on the day of oocyte retrieval disrupts the receptive endometrium and has a negative impact on implantation and IVF outcomes. Management of repeated implantation failure despite transfer of good-quality embryos still remains a dilemma for ART specialists. Scrapping of endometrium in the nontransfer cycle has been shown to improve the pregnancy rate in the subsequent IVF/ET cycle in recent studies.
                The objective of this randomized controlled trial (RCT) was to determine whether endometrial injury caused by Pipelle sampling in the nontransfer cycle could improve the probability of pregnancy in the subsequent IVF cycle in patients who had previous failed IVF outcome.
                Tertiary assisted conception center.
                Randomized controlled study.
                100 eligible patients with previous failed IVF despite transfer of good-quality embryos were randomly allocated to the intervention group and control groups. In the intervention group, Pipelle endometrial sampling was done twice: One in the follicular phase and again in the luteal phase in the cycle preceding the embryo transfer cycle.
                The primary outcome measure was live birth rate. The secondary outcome measures were implantation and clinical pregnancy rates.
                The live birth rate was significantly higher in the intervention group compared to control group (22.4% and 9.8% P = 0.04). The clinical pregnancy rate in the intervention group was 32.7%, while that in the control group was 13.7%, which was also statistically significant (P = 0.01). The implantation rate was significantly higher in the intervention group as compared to controls (13.07% vs 7.1% P = 0.04).
                Endometrial injury in nontransfer cycle improves the live birth rate, clinical pregnancy and implantation rates in the subsequent IVF-ET cycle in patients with previous unsuccessful IVF cycles. This randomized controlled study was performed in an unselected IVF/ICSI population to test the hypothesis that blastocyst transfers result in higher clinical pregnancy rates (CPR) per oocyte retrieval when compared with day 2 transfers.
                Blind randomization for transfer on day 2 (group 1) or day 5/6 (group 2) was performed before stimulation. Oocytes and embryos were cultured in sequential media in 5.5% CO(2), 5% O(2), 89.5% N(2) and 90% humidity. A maximum of two embryos was transferred.
                The two groups were similar for age, IVF indication, number of treatment cycles, rate of ICSI/IVF, number of fertilized oocytes and number of embryos transferred. The CPR/oocyte retrieval was comparable in group 1 (32%) and in group 2 (44%), while the CPR/embryo transfer was significantly higher (P < 0.01) in group 2 (60%) than in group 1 (35%). Similarly, the implantation rate per embryo transferred was significantly higher (P < 0.03) in group 2 (46%) than in group 1 (29%). The cryo-augmented delivery rate/oocyte retrieval was comparable in group 2 (36.3%) and in group 1 (28.6%).
                This randomized study in an unselected population showed a significantly higher CPR/embryo transfer and a tendency toward a higher CPR/oocyte retrieval in patients receiving blastocysts when compared with day 2 transfers.
Endometrial injury performed prior to the embryo transfer cycle improves clinical pregnancy and live birth rates in women undergoing ART. It is advisable not to perform endometrial injury on the day of oocyte retrieval because it appears to significantly reduce clinical and ongoing pregnancy rates. There is insufficient evidence regarding the effect of endometrial injury on multiple pregnancy or miscarriage and none on adverse events such as pain and bleeding.