Periconceptional Folic Acid Supplementation And The Incidence And Perinatal Outcome Of Twin Pregnancy: A Meta-analysis

Objective To assess quantitatively the association betweenpericonceptional folic acid supplementation and the incidence and perinataloutcome of twin pregnancy by Meta-analysis.Methods Literatures associated with periconceptional folic acidsupplementation and twin pregnancy between1966and2012were collectedsystematically from PubMed, MEDLINE, Embase, Ovid, Cochrane CentralRegister of Clinical Trials，Google Scholarism，China National KnowledgeInternet (CNKI), VIP, Wanfang databases, then were screened strictlyaccording to the pre-established inclusion standards and exclusion standards.Quality was evaluated strictly. Data were extracted according to thepre-established table, and then were meta-analyzed by RevMan5.2software.Results Eventually four randomized controlled trial (RCT) studieswere eligible. Results of Meta-analysis showed: according to the differentinterventions of periconceprional supplementation, such as folic acid, folic acid with multivitamins, folic acid with or without multivitamins,multivitamins, placebo-like trace-element, et al., and the different courses ofsupplementation, such as full, partial, et al., there were no statisticallysignificant differences of the incidences of twin pregnancy between casegroup and control group (P>0.05). There were also no statisticallysignificant differences of the types of zygosity，the basic informations or theadverse perinatal outcomes of twin pregnancy between two groups (P>0.05).Conclusion There were no evidences for significant associationsbetween periconceptional folic acid supplementation and the incidence oftwin pregnancy or the zygosity of twin pregnancy. We found no influenceson the incidences of fetal death, neonatal mortality, congenital abnormalitiesor minor anomalies of twin births from periconceptional folic acidsupplementation in our analysis.