Maternal diabetes mellitus and infant malformations

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Pediatrics

Background:

• Diabetes mellitus in pregnancy presents diagnostic challenges, with distinct forms including pregestational and gestational diabetes.
• Gestational diabetes mellitus (GDM) is further categorized by glycemic control, impacting maternal and fetal outcomes.
• Infant malformations represent a critical concern in pregnancies affected by diabetes.

Purpose of the Study:

• To differentiate the teratogenic effects of pregestational diabetes versus gestational diabetes on infant malformations.
• To assess the impact of varying degrees of gestational diabetes on the incidence of congenital anomalies.

Main Methods:

• A retrospective cohort study analyzed 145,196 deliveries at Parkland Hospital (1991-2000).
• Gestational diabetes screening utilized National Diabetes Data Group criteria.
• Infant malformations were defined and categorized by organ system involvement.

Main Results:

• A total of 2687 (1.9%) women had diabetes; 410 (0.3%) had pregestational diabetes and 2277 (1.6%) had gestational diabetes.
• Infant malformation rates were 1.5% (non-diabetic), 1.2% (mild GDM), 4.8% (GDM with hyperglycemia), and 6.1% (pregestational diabetes).
• Both pregestational diabetes and GDM with hyperglycemia showed significantly higher malformation rates (P <.001).

Conclusions:

• Pregestational diabetes and gestational diabetes with hyperglycemia confer a 3-4 fold increased risk of infant malformations.
• Mild gestational diabetes, characterized by normal fasting glucose, does not increase malformation risk compared to non-diabetic pregnancies.
• Risk stratification for infant malformations is crucial in managing diabetes during pregnancy.