Oil-based versus water-based contrast for hysterosalpingography in infertile women: a systematic review and meta-analysis of randomized controlled trials

Objective: To determine the effect of the using oil-soluble contrast material (OSCM) vs. water-soluble contrast material (WSCM) for hysterosalpingography on pregnancy rates in infertile women. Design: Systematic review and meta-analysis. Setting: Not applicable. Patient(s): Infertile women. Intervention(s): We included randomized controlled trials comparing pregnancy outcomes in women with infertility undergoing hysterosalpingography using OSCM and WSCM. Paired reviewers independently screened citations, assessed risk of bias of included studies, and extracted data. A random-effects model was used to report all outcomes. The Grading of Recommendations Assessment, Development, Evaluation(GRADE) system was used to quantify absolute effects and quality of evidence. Main Outcome Measure(s): The primary outcome was ongoing pregnancy per randomized women. Result(s): Six trials with a total of 2,562 patients were selected. Our meta-analysis showed OSCM was associated with significantly higher rates of ongoing pregnancy compared with WSCM (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.12-1.93; I-2 = 44%, moderate-quality evidence). Three trials reported live birth, but they were not pooled owing to extreme statistical heterogeneity (I-2 = 86%). There was no difference in incidence of miscarriage (OR 0.83, 95% CI 0.56-1.24) or ectopic pregnancy (OR 0.65, 95% CI 0.18-2.36) between OSCM and WSCM groups. Three trials were rated as low risk of bias, whereas three were considered unclear. Conclusion(s): Women who previously underwent hysterosalpingography using oil contrast had higher rates of ongoing pregnancy compared with women who underwent this procedure using water contrast. There is not enough evidence to either support or oppose the difference between groups concerning miscarriage and ectopic pregnancy. (C) 2018 by American Society for Reproductive Medicine.