Continued Metformin Therapy During Pregnancy For Women With Polycystic Ovary Syndrome: A Meta Analysis

Objective:To conduct a systematic review and meta-analysis of pregnancy outcomes in women with PCOS who conceived while on metformin treatment and continued the medication for at least the first trimester during pregnancy.Materials and method:A systematic review was conducted with all pertinent studies that were found in PUBMED,CBM that examined Polycystic ovary syndrome and metformin and gestational diabetes mellitus. Literature references were checked at the same time. Languages was restricted to Chinese and English. The study group consisted of women with PCOS who conceived while on metformin treatment and continued the medication for at least the first trimester during pregnancy. The control groups consisted of disease-matched women who were not treated with metformin.Meta-analysis was conducted using Review Manager 4.2 software (Review Manager [RevMan] [computer program]. Version 4.2 for Windows. Oxford, England:The Cochrane Collaboration,2002). Data including gestational diabetes incidence, the incidence of spontaneous abortion,hypertensive disorders and fetal growth restriction incidence, and the incidence of fetal abnormalities respectively. Using the index of relative risk to express the result for the categorical variable.Results:There are six trials including 641 patients were included, including two randomized clinical trials,4 the controlled clinical trial. None of the CCT described randomization or usage of double blinded. Results showed that continued metformin during pregnancy vesus and disable metformin groups:(1) continued metformin can significantly reduce the diabetes polycystic oary syndrome pregnant gestational diabetes risk, relative risk RR to 0.33, (95% CI:0.023-0.48, p<0.00001).(2) Continued metformin, can significantly reduce spontaneous abortion, RR=0.28, (95%CI:0.18-0.43, p<0.00001). (3)Use metformin throughout pregnancy, the incidence of hypertensive disorders is 13.9% vesus 38.4%, its differences is statistically significant (p=0.002); fetal growth restriction rates is 2.3%compared to 19.2%. (4)metformin use throughput pregnancy can significantly reduce the incidence of fetal growth restriction(p=0.026). (5)There is no evidence of an increased risk for major malformations when metformin is taken during the first trimester of pregnancy.Conclusion:Continued application of metformin could significantly reduce non-diabetic PCOS women risk of gestational diabetes mellitus. Continued metformin use could significantly reduce spontaneous abortion rate. Use metformin throughout pregnancy period can significantly reduce hypertensive disorders and fetal growth restriction rates. No evidence of an increased risk for major malformations when metformin is taken during the first trimester of pregnancy.More RCT are needed to corroborate these preliminary results.