Comparison of fertility outcomes between oil‑based and water‑based contrast media during hysterosalpingography: A meta‑analysis

Water-based and oil-based contrast media are both widely used in clinical practice for patients receiving hysterosalpingography (HSG). However, minor controversy exists about whether the oil-based contrast medium has a superior fertility-enhancing effect during HSG. The present meta-analysis intended to comprehensively compare the fertility outcomes of patients receiving either an oil-based or a water-based contrast medium during HSG. Web of Science, PubMed, Excerpta Medica Database, Cochrane, China National Knowledge Infrastructure, Wanfang Data and China Science and Technology Journal Database were examined for literature comparing the fertility enhancement between oil-based and water-based contrast media during HSG up to November 10, 2022 and there was no cut off for studies published earlier than any given year. Data for clinical pregnancy, ongoing pregnancy, live birth, miscarriage and ectopic pregnancy were extracted and analyzed. A total of 11 studies with 2,462 patients receiving oil-based contrast medium and 2,830 patients receiving water-based contrast medium during HSG were included. Relative risks (RRs) and 95% confidence intervals (CIs) were presented for outcome assessment, and the random effects model was utilized for all analyses. Publication bias was analyzed using Egger's and Begg's tests. The results indicated that the rate of clinical pregnancy was increased using oil-based contrast medium compared with water-based contrast medium [relative risk (RR) (95% CI), 1.29 (1.07, 1.54); P=0.006]. In addition, the rate of ongoing pregnancy [RR (95% CI), 1.39 (1.22, 1.59); P#x003C;0.001] and live birth [RR (95% CI), 1.41 (1.07, 1.87); P=0.016] were also increased using oil-based contrast medium compared with water-based contrast medium. However, miscarriage [RR (95% CI), 1.06 (0.61, 1.86); P=0.833] and ectopic pregnancy [RR (95% CI), 0.66 (0.18, 2.36); P=0.518] were not affected by using oil-based or water-based contrast medium. Begg's test and Egger's test suggested that no publication bias of clinical pregnancy, ongoing pregnancy, live birth, miscarriage and ectopic pregnancy existed (all P>0.05), which indicated the stability of the present meta-analysis. In conclusion, the oil-based contrast medium enhances fertility outcomes compared with the water-based contrast medium in patients receiving HSG.