Objective  To explore direct and indirect effect of social environment factors on adverse birth outcomes.

  Methods  The data on the women of childbearing age and their children were obtained through a survey on the status of birth defects and their risk factors in Shaanxi province and the information about health development in 30 districts and counties in Shaanxi province were extracted from health statistics yearbook of Shaanxi province – 2010. Confirmatory factor analysis was used to construct five latent variables (health development, family characteristics, maternal and child health care utilization, folic acid supplement use, and adverse birth outcomes) and to establish a hypothesis structure model involving the latent variables. And then the best model was determined with modification and evaluation using structural equation model method.

  Results  The participants of the study were 28 457 women aged 15 – 49 years and being pregnant and with definite pregnancy outcome during the period from 2010 through 2013. Of all the deliveries of the pregnant women, 2.0%, 2.7%, and 3.4% were birth defect, premature delivery, and low birth weight. The established structural equation model revealed that health service development affected the occurrence of adverse birth outcomes indirectly through the influence of maternal and child health care utilization and folic acid supplement use; maternal and child health care utilization influenced birth outcomes indirectly through folic acid supplement use. Family characteristics exerted direct and indirect effect on adverse birth outcomes mainly through maternal and child health care utilization and folic acid supplement use; whereas folic acid supplement use had a direct impact on the occurrence of adverse birth outcomes. The effect of family characteristics was the greatest (53.3%), followed by that of folic acid supplement use (30.0%), maternal and child health care utilization (12.7%), and the development of health service (4.0%).

  Conclusion  Health service development, family characteristics, maternal and child health care utilization, and folic acid supplement use exert direct or indirect impact on adverse birth outcomes, and the effect of family characteristics is the greatest. The results suggest that family-based social interventions should be adopted in the intervention on adverse birth outcomes.