A meta-analysis of fertility and adverse outcomes in oil- and water-based contrast for hysterosalpingography

Infertility is the inability to conceive after one year of regular unprotected intercourse. There is a debate about the therapeutic effect of hysterosalpingography (HSG) and whether the selection of contrast materials makes a difference in the chance of subsequent conception. In this study, we aimed to compare the fertility-enhancing outcomes and adverse effects of oil and water-based contrasts in patients who underwent HSG. This systematic review and meta-analysis was conducted following the PRISMA guidelines. We searched the Web of Science, PubMed, and Scopus until September 2022. We included all primary randomized controlled trials evaluating the fertility-enhancing benefits of HSG in oil-based versus water-based contrast media in women of childbearing age with infertility. Eleven studies with 4,739 patients were selected. The pregnancy rate in the oil group was significantly higher than that in the water group [odds ratio (OR)=1.51 (1.23, 1.86), p<0.0001]. Our meta-analysis favored the oil group in abdominal pain and vaginal bleeding with the odd ratios of 0.73 (0.58, 0.91), (p=0.006) and 0.91 (0.46, 1.81), (p=0.79), respectively. Water-based contrast was associated with less intravasation [OR=2.09 (1.09-4.02), p=0.03]. There were no differences between the contrasts for miscarriage [OR=1.02 (0.71, 1.46), p=0.92], and ectopic pregnancy [OR=0.84 (0.27, 2.63), p=0.77]. HSG with oil-based contrast was related to a higher pregnancy rate, live birth rate, and intravasation rate. While HSG using a water-based contrast medium was associated with increased abdominal discomfort, vaginal bleeding, and the visual-analogue scale pain score.