Effectiveness on fertility outcome of tubal flushing with different contrast media: systematic review and network meta-analysis

Objectives: To compare, in women with infertility, the effectiveness and safety of tubal flushing using oil-based contrast medium, water-based contrast medium or their combination, and no tubal flushing, and to evaluate the effectiveness of tubal flushing on fertility outcome over time. Methods: We performed a systematic review and network meta-analysis, searching the electronic databases MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials, and trial registries, up to 25 September 2018. We included randomized controlled trials (RCTs) comparing the following interventions with each other or with no intervention in women with infertility: tubal flushing using water-based contrast medium, tubal flushing using oil-based contrast medium or additional tubal flushing with oil-based medium following diagnostic tubal flushing with water-based medium. The outcomes included clinical pregnancy, live birth, ongoing pregnancy, miscarriage, ectopic pregnancy and adverse events. Results: Of the 283 studies identified through the search, 14 RCTs reporting on 3852 women with infertility were included. Network meta-analysis showed that tubal flushing using oil-based contrast medium was associated with higher odds of clinical pregnancy within 6 months after randomization and more subsequent live births compared with tubal flushing using water-based medium (odds ratio (OR), 1.67 (95% CI, 1.38–2.03), moderate certainty of evidence; and OR, 2.18 (95% CI, 1.30–3.65), low certainty of evidence, respectively) and compared with no intervention (OR, 2.28 (95% CI, 1.50–3.47), moderate certainty of evidence; and OR, 2.85 (95% CI, 1.41–5.74), low certainty of evidence, respectively). These results agreed with those of the pairwise meta-analysis. For clinical pregnancy within 6 months, there was insufficient evidence of a difference between tubal flushing with water-based contrast medium and no intervention (OR, 1.36 (95% CI, 0.91–2.04), low certainty of evidence). For fertility outcomes after 6 months, there was insufficient evidence of a difference in any comparison (low to very low certainty of evidence). Compared with tubal flushing using water-based contrast medium, the use of oil-based contrast medium was associated with higher odds of asymptomatic intravasation (OR, 5.06 (95% CI, 2.29–11.18), moderate certainty of evidence). Conclusions: In women with infertility undergoing fertility workup, tubal flushing using oil-based contrast medium probably increases clinical pregnancy rates within 6 months after randomization and may increase subsequent live-birth rates, compared with tubal flushing using water-based contrast medium and compared with no intervention. Evidence on fertility outcomes beyond 6 months is inadequate to draw firm conclusions.