[Effect of folic acid supplementation in childbearing aged women during pregnancy on neonate birth weight in Shaanxi province].

OBJECTIVE: To investigate the effect of folic acid supplementation in childbearing aged women during pregnancy on the birth weight of newborns in Shaanxi province. METHODS: A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013, all of these childbearing aged women were in pregnancy or had definite pregnancy outcomes. The birth weight of newborns and folic acid supplementation during pregnancy were used as the dependent variables and independent variables respectively in multiple linear regression model and quantile regression model and confounding factors were controlled. RESULTS: Multiple linear regression analysis showed that the birth weight of newborns whose mothers had folic acid supplementation during pregnancy were significantly higher than those whose mothers had no folic acid supplementation during pregnancy, an average increase of 29.56 g(B=29.56, t=4.69 and P<0.01). Quantile regression analysis showed from very low to higher percentiles(q=0-0.55, q=0.65, q=0.75-0.80), the birth weights of newborns whose mothers supplemented folic acid were higher than those whose mother did not supplement folic acid, the difference was significant, but the increase varied. As the increase of the percentiles of birth weight, the body weight increase declined gradually in those whose mothers had folic acid supplementation compared with those whose mothers had no folic acid supplementation. CONCLUSION: Folic acid supplementation during pregnancy can increase the birth weight of newborns, the influence was greater in newborns with lower body weight than in newborns with higher body weight.