Endometrial thickness and pregnancy rates after IVF: a systematic review and meta-analysis

Thin endometrium on ultrasound in the course of ovarian hyperstimulation has been thought to be associated with poor success rates after IVF, even in the absence of prior intrauterine surgery or infection. To assess the clinical significance of endometrial thickness (EMT) for IVF outcome, we performed a systematic review and meta-analysis.

The electronic databases Pubmed, Cochrane and Embase were searched up to October 2013 for articles that studied the association between EMT and IVF outcome. The articles had to be written in the English or Dutch language. Studies were included if two-by-two tables for EMT and pregnancy rates could be constructed. Study quality was scored using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. Summary receiver operating characteristic (sROC) curves were estimated to assess the accuracy of EMT in the prediction of pregnancy. In addition, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a Mantel-Haenszel random effect model expressing the association between EMT and pregnancy chances. Meta-regression was performed to determine if female age and number of oocytes at retrieval interacted in the estimated effect of EMT on IVF outcome.