Effects of phloroglucinol on embryo transfer: a systematic review and meta-analysis

Introduction: Phloroglucinol may be able to improve embryo transfer outcomes. We aimed to systematically evaluate the effects of phloroglucinol on embryo transfer outcomes. Methods: The databases searched were PubMed, Ovid MEDLINE, Web of Science, Wanfang, CQVIP, China National Knowledge Infrastructure, and <ext-link ext-link-type="uri" xlink:href="http://ClinicalTrials.gov" xmlns:xlink="http://www.w3.org/1999/xlink">ClinicalTrials.gov</ext-link>. The last search was on February 7, 2023. The included studies were written in English or Chinese. Randomized controlled trials and cohort studies aiming to assess the effect of phloroglucinol on embryo transfer outcomes were included. The studies reported at least one of the primary outcomes (biochemical pregnancy rate, clinical pregnancy rate, and live birth rate). The odds ratio (OR) and 95% confidence interval (CI) were calculated. A random-effects or fixed model was used where applicable to estimate the results. Results: Seventeen articles reporting 5,953 cycles were included. Biochemical pregnancy rate (OR = 1.58, 95% CI = 1.20–2.08, I2 = 71%), clinical pregnancy rate (OR = 1.69, 95% CI = 1.35–2.10, I2 = 64%), and live birth rate (OR = 1.45, 95% CI = 1.23–1.71, I2 = 36%) were improved by phloroglucinol. Less miscarriage (OR = 0.46, 95% CI = 0.35–0.60, I2 = 0%), less ectopic pregnancy (OR = 0.45, 95% CI = 0.28–0.72, I2 = 0%), higher implantation rate (OR = 1.45, 95% CI = 1.24–1.71, I2 = 62%) but more multiple pregnancy rate (OR = 1.48, 95% CI = 1.13–1.94, I2 = 0%) were induced by phloroglucinol. Endometrial peristaltic waves were improved by phloroglucinol (OR = 22.87, 95% CI = 5.52–94.74, I2 = 72%). Conclusion: Phloroglucinol may improve the outcomes of embryo transfer, including biochemical pregnancy, clinical pregnancy, and live birth rates. Further studies are warranted.