The Effects of Periconceptional Risk Factor Exposure and Micronutrient Supplementation on Birth Defects in Shaanxi Province in Western China

OBJECTIVES 1) To understand the current prevalence and main types of birth defects, 2) assess the periconceptional exposure of factors associated with birth defects in Shaanxi Province, and 3) provide scientific evidence for local governments to formulate services for the primary prevention of birth defects. METHODS We sampled 16,541 households from 128 townships in 16 counties/districts in Shaanxi province using a multi-stage random sampling method. Among them, 10,544 women who had live born or stillborn infants with gestational age ≥ 28 weeks between 2008 and 2009 were interviewed using a structured questionnaire designed to collect information about periconceptional risk factor exposure, health care service utilization, and micronutrient supplements. Logistic regression was performed to assess the risk factors associated with birth defects and adjustments were made for imbalanced social-demographic characteristics between case and control groups. RESULTS The prevalence of congenital birth defect in Shaanxi province was 14.3/1000 births. The environment risk factors associated with birth defects include unhealthy lifestyle (Alcohol, odds ratio (OR): 3.60, 95% confidence interval (CI) 1.64-7.91; Smoking, OR: 1.32, 95% CI: 0.99-1.75; Drink strong tea, OR: 1.81, 95% CI: 1.27-2.59), exposure to heavy pollution (OR: 1.53, 95% CI: 1.01-2.30), maternal diseases (OR: 1.77, 95% CI: 1.35-2.33), drug use (OR: 2.11, 95% CI: 1.51-2.95), maternal chemical pesticide exposure (OR: 2.30, 95% CI: 1.16-4.57), and adverse pregnancy history (OR: 10.10, 95% CI: 7.55-13.53). Periconceptional folic acid or multiple micronutrients including folic acid supplementation, was associated with a reduced rate of birth defects (OR: 0.54, 95% CI: 0.29-0.998). CONCLUSIONS Health care service utilization, unhealthy lifestyle factors, and environment risk factors seem to be associated with birth defects in Shaanxi province. Governmental agencies should focus on effective primary preventative methods, such as the delivery of periconceptional health education for minimizing potential risk factor exposures, periconceptional folic acid or micronutrient supplementation, environment monitoring, and assessment of factories with high levels of pollution.