Follicle flushing does not improve live birth and increases procedure time: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To determine whether follicle flushing during oocyte retrieval improves live birth or secondary outcomes in assisted reproductive technology (ART). DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Women undergoing ART using autologous gametes. INTERVENTION(S): A systematic search of PubMed, EMBASE, Cochrane Database, and Web of Science for randomized controlled trials comparing follicle flushing to direct aspiration during oocyte retrieval published in English between 1989 to 2020. MAIN OUTCOME MEASURE(S): Live birth as primary outcome, and clinical and ongoing pregnancy, total and mature metaphase II (MII) oocytes retrieved, and operating time as secondary outcomes. RESULT(S): Eleven studies were included totaling 1,178 cases. No difference in live birth was demonstrated between follicle flushing and direct aspiration. Clinical pregnancy and ongoing pregnancy were not improved with flushing. Total oocyte and MII yield were lower with flushing compared with direct aspiration. Procedure time was increased with flushing by 2 minutes in poor responders and 9 minutes in normal responders. Other sensitivity analyses did not demonstrate any changes, except the difference in MII yield was no longer statistically significant. CONCLUSION(S): Follicle flushing during oocyte retrieval increases procedure time and does not improve live birth or secondary ART outcomes. Randomized data do not support the use of follicle flushing as an intervention in ART.