[Pregnancy complications among women with polycystic ovary syndrome in China: a Meta-analysis].

OBJECTIVE: To estimate the status of pregnancy complications among women with polycystic ovary syndrome (PCOS) through a systematic review of published literatures.
 Methods: Systematic literature searches were conducted in PubMed, Web of Science, Medline, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, Weipu and China Biology Medicine disc (CBMdisc), as well as the relevant articles published from inception to April 1st 2017, which reported the prevalence of pregnancy complications among women with PCOS. Random effective models were used to calculate pooled prevalence and 95% confidence intervals. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of those included studies. Subgroup analyses were used to evaluate the influence of overweight/obesity and insulin resistance before pregnancy on the estimates of pregnancy complications among women with PCOS.
 Results: Fifty-nine studies involving 13 378 PCOS women and 49 395 non-PCOS women were included. Among women with PCOS, pooled estimates were 20.26% for gestational diabetes mellitus, 13.94% for hypertensive disorder of pregnancy, 64.16% for caesarean section, 13.35% for preterm birth, 9.84% for macrosomia, 5.88% for low birth weight, 5.25% for early gestational age, 8.45% for late gestational age, 1.93% for neonatal malformations, 0.88% for perinatal mortality and 3.71% for neonatal asphyxia. And the estimates of gestational diabetes mellitus, hypertensive disorder of pregnancy, caesarean section, preterm birth, macrosomia and neonatal asphyxia among women with PCOS were significantly higher than those in women without PCOS (all P<0.05). Subgroup analysis showed the estimates of gestational diabetes mellitus, macrosomia and late gestational age among PCOS women who were overweight/obesity before pregnancy were significant higher than those among PCOS women with normal BMI (all P<0.05); and compared to PCOS women without insulin resistance prior to pregnancy, PCOS women with pre-pregnancy insulin resistance were at an increased risk for gestational diabetes mellitus, preterm birth and macrosomia (all P<0.05).
 Conclusion: PCOS in pregnancy is associated with high rates of pregnancy complications. It is an important risk factor for pregnancy complications.