Maternal diabetes mellitus and birth defects in Taiwan: A 5-year nationwide population-based cohort study.

Background: Birth defects (BDs) are the main causes of mortality and disability in infants and children. Associations between maternal diabetes mellitus (DM), including gestational DM (GDM) and pregestational DM (type 1 or type 2), and the risk of BDs have been reported. This study aims to determine the relationship between maternal DM and BDs and to investigate whether reducing the incidence of DM can decrease the incidence of BDs.

Methods: We identified all births in Taiwan from the National Birth Defects Surveillance Program between January 1, 2010, and December 31, 2014. Information on the infants' characteristics (sex, gestational age, and birth weight) and mothers' characteristics (age, parity, and associated diseases, including DM) were obtained from the National Birth Registry and National Health Insurance Research Database (NHIRD) in Taiwan. BDs were coded according to the International Classification of Diseases, 9th Revision-Clinical Modification (ICD-9-CM) codes 740-759.

Results: Multiple logistic regression analysis with adjusted odds ratio (aOR) and 95% confidence interval (95% CI) for all BDs showed that the aOR (95% CI) was 1.002 (0.965-1.041), and the p -value was 0.9139 in the GDM group. In the type 1 DM group, the aOR (95% CI) was 1.748 (1.110-2.754), and the p -value was 0.016. In the type 2 DM group, the aOR (95%CI) was 1.175 (1.005-1.375), 1.331 (1.196-1.482), and 1.391 (1.216-1.592), and the p -value was 0.0437, <0.0001, and <0.0001 for the duration of mothers with type 2 DM <2, 2 to 5, >5 years, respectively.

Conclusion: Mothers with pregestational DM (type 1 or type 2) increase the incidence of BD. Appropriate maternal glycemic control may achieve good pregnancy and perinatal outcomes.