The different effects of prenatal nutrient supplementation on neonatal birth weights between urban and rural areas of northwest China: a cross-sectional study

摘要

BACKGROUND AND OBJECTIVES: The results of prenatal nutrient supplementation on birth weight are inconsistent in different areas. This study aimed to investigate whether the effects of prenatal iron plus folic acid and folic acid supplementation on neonatal birth weights differed between urban and rural areas of Northwest China. METHODS AND STUDY DESIGN: A stratified multistage random sampling method was used to recruit women between the ages of 15 and 49 and their offspring born between 2010 and 2013 from 10 urban areas and 20 rural areas of the Shaanxi Province of Northwest China. Information regarding socio-demographics and prenatal nutrient supplementation status was collected using a standardized questionnaire, and the neonatal birth weights were obtained from the birth certificates. Multilevel models were established separately for the urban and rural areas to assess the effects of prenatal nutrient supplementation on neonatal birth weights. RESULTS: The association between prenatal nutrient supplementation and neonatal birth weight was not statistically significant in urban areas. However, in rural areas, prenatal iron plus folic acid and folic acid supplementation increased the mean birth weights by 45.3 g (9.4 to 81.1 g, p=0.014) and 30.9 g (15.6 to 46.1 g, p<0.001), respectively. CONCLUSIONS: The effects of prenatal nutrient supplementation on neonatal birth weights differ between urban and rural areas of Northwest China. The different effects may be due to the different nutritional status of the urban and rural pregnant women. Prenatal nutrient supplementation may be a helpful way for improving neonatal birth weight in rural areas.