Endometrial scratching in women undergoing IVF/ICSI: an individual participant data meta-analysis.

BACKGROUND: In IVF/ICSI treatment, the process of embryo implantation is the success rate-limiting step. Endometrial scratching has been suggested to improve this process, but it is unclear if this procedure increases the chance of implantation and live birth (LB) and, if so, for whom, and how the scratch should be performed. OBJECTIVE AND RATIONALE: This individual participant data meta-analysis (IPD-MA) aims to answer the question of whether endometrial scratching in women undergoing IVF/ICSI influences the chance of a LB, and whether this effect is different in specific subgroups of women. After its incidental discovery in 2000, endometrial scratching has been suggested to improve embryo implantation. Numerous randomized controlled trials (RCTs) have been conducted, showing contradicting results. Conventional meta-analyses were limited by high within- and between-study heterogeneity, small study samples, and a high risk of bias for many of the trials. Also, the data integrity of several trials have been questioned. Thus, despite numerous RCTs and a multitude of conventional meta-analyses, no conclusion on the clinical effectiveness of endometrial scratching could be drawn. An IPD-MA approach is able to overcome many of these problems because it allows for increased uniformity of outcome definitions, can filter out studies with data integrity concerns, enables a more precise estimation of the true treatment effect thanks to adjustment for participant characteristics and not having to make the assumptions necessary in conventional meta-analyses, and because it allows for subgroup analysis. SEARCH METHODS: A systematic literature search identified RCTs on endometrial scratching in women undergoing IVF/ICSI. Authors of eligible studies were invited to share original data for this IPD-MA. Studies were assessed for risk of bias (RoB) and integrity checks were performed. The primary outcome was LB, with a one-stage intention to treat (ITT) as the primary analysis. Secondary analyses included as treated (AT), and the subset of women that underwent an embryo transfer (AT+ET). Treatment-covariate interaction for specific participant characteristics was analyzed in AT+ET. OUTCOMES: Out of 37 published and 15 unpublished RCTs (7690 participants), 15 RCTs (14 published, one unpublished) shared data. After data integrity checks, we included 13 RCTs (12 published, one unpublished) representing 4112 participants. RoB was evaluated as 'low' for 10/13 RCTs. The one-stage ITT analysis for scratch versus no scratch/sham showed an improvement of LB rates (odds ratio (OR) 1.29 [95% CI 1.02-1.64]). AT, AT+ET, and low-RoB-sensitivity analyses yielded similar results (OR 1.22 [95% CI 0.96-1.54]; OR 1.25 [95% CI 0.99-1.57]; OR 1.26 [95% CI 1.03-1.55], respectively). Treatment-covariate interaction analysis showed no evidence of interaction with age, number of previous failed embryo transfers, treatment type, or infertility cause. WIDER IMPLICATIONS: This is the first meta-analysis based on IPD of more than 4000 participants, and it demonstrates that endometrial scratching may improve LB rates in women undergoing IVF/ICSI. Subgroup analysis for age, number of previous failed embryo transfers, treatment type, and infertility cause could not identify subgroups in which endometrial scratching performed better or worse. The timing of endometrial scratching may play a role in its effectiveness. The use of endometrial scratching in clinical practice should be considered with caution, meaning that patients should be properly counseled on the level of evidence and the uncertainties.

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.

BACKGROUND: 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. AIM: 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. SETTING: Tertiary assisted conception center. DESIGN: Randomized controlled study. MATERIALS AND METHODS: 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. OUTCOME MEASURE: The primary outcome measure was live birth rate. The secondary outcome measures were implantation and clinical pregnancy rates. RESULTS: 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). CONCLUSIONS: 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.

The degree of serum estradiol decline in early and midluteal phase had no adverse effect on IVF/ICSI outcome.

BACKGROUND: Estradiol levels fall rapidly in the luteal phase of ART cycles. So far, the effect of this estradiol decline on pregnancy outcome has remained controversial. AIM: To study the effect of early and midluteal estradiol decline on pregnancy and miscarriage rate. We also sought to determine whether estradiol fall was related to increased risk of bleeding per vagina in the first trimester among pregnancies which crossed 12 weeks. SETTING: Tertiary Assisted conception center. DESIGN: Retrospective study. MATERIALS AND METHODS: We analyzed data of 360 consecutive patients who underwent IVF-ET/ICSI cycles using one of the three protocols: Midluteal downregulation, short flare, and antagonist protocol. STATISTICAL METHODS: Statistical evaluation was performed with the Student's t test, Chi square, Fischer's exact test, analysis of variance, and Mann-Whitney tests were appropriate using SPSS for Windows, Standard version 11.0. RESULTS: The mean % EL-E2 and % ML-E2 declines were not significantly different in the pregnant and nonpregnant groups when analyzed separately in the three protocols. Also, the degree of midluteal estradiol decline did not correlate with pregnancy outcome. Moreover, the mean % early and midluteal estradiol decline did not differ significantly in patients with preclinical, clinical abortions, and ongoing pregnancy. The estradiol decline was not found to influence the risk of bleeding in the first trimester. CONCLUSIONS: Our results show that the degree of estradiol fall in the luteal phase of ART cycles does not influence pregnancy and first trimester miscarriage rate.