A propensity-matched study of the association between optimal folic acid supplementation and birth defects in Shaanxi province, Northwestern China

Pengfei Qu,Danmeng Liu,Fangliang Lei,Duolao Wang,Shanshan Li,Lingxia Zeng,Shaonong Dang,Wenhao Shi,Hong Yan,Juanzi Shi

doi:10.1038/s41598-019-41584-5

Abstract

The association between folic acid supplementation and birth defects other than neural tube defects remains unclear. We utilized data from a large population-based survey to examine the association between folic acid supplementation and birth defects in Northwestern China. A total of 29,204 women with infants born between 2010 and 2013 were surveyed in Shaanxi province, Northwestern China, using a stratified multistage sampling method. Propensity scores were used to match 9,293 women with optimal folic acid supplementation with 9,293 women with nonoptimal folic acid supplementation, and the effects of optimal folic acid supplementation on birth defects were assessed by a conditional logistic regression model. After propensity score matching, the overall birth defect rate, cardiovascular system defect rate and nervous system defect rate for the women with optimal folic acid supplementation were lower than those for the women with nonoptimal folic acid supplementation (overall birth defects: OR = 0.71, 95% CI = 0.57–0.89, P = 0.003; cardiovascular system defects: OR = 0.65, 95% CI = 0.44–0.96, P = 0.032; nervous system defects: OR = 0.13, 95% CI = 0.02–0.99, P = 0.049). Optimal folic acid supplementation was associated with a decreased prevalence of birth defects, especially in the cardiovascular system and nervous system. Our findings have important implications for birth defect intervention with folic acid supplementation for countries with a high prevalence of birth defects, such as China.

Highlights

“Birth defect” is a general term for functional or structural abnormalities in a developing fetus
Among the birth defects surveyed, we identified 192.44 cases of overall birth defects before propensity score (PS) matching, including 6.85 cases of nervous system defects; 23.97 cases of eye, ear, face and neck defects;, 63.35 cases of cardiovascular system defects; 3.77 cases of respiratory system defects; 11.64 cases of oral clefts; 8.56 cases of digestive system defects; 5.82 cases of genital organ defects; 2.05 cases of urinary system defects; 34.58 cases of musculoskeletal system defects; 0.68 cases of chromosomal abnormalities; and 31.16 cases of other defects (Table 1)
This study investigated the association between folic acid supplementation and the birth defect spectrum, and our findings demonstrated that optimal folic acid supplementation was associated with a decreased risk of overall birth defects in Northwest China, especially nervous system and cardiovascular system defects

Summary

Introduction

“Birth defect” is a general term for functional or structural abnormalities in a developing fetus. There are approximately 0.25 million births with major defects every year in China, which leads to a substantial disease burden[2]. Both randomized controlled studies and observational studies have confirmed that periconceptional folic acid supplementation can reduce the prevalence of neural tube defects[3,4,5,6]. The relationships between periconceptional folic acid supplementation and other birth defects, such as cardiovascular system defects, oral clefts, and urinary system defects, remain inconclusive. The objective of this study was to investigate the association between periconceptional folic acid supplementation and birth defects using PS methods in Shaanxi province, Northwest China

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Conclusion