What is the most common congenital abnormality in diabetic pregnancies?

Hypoglycemia, polycyt. Metabolic derngement such as hypoglycemia, hypocalcemia, polycythemia, congenital heart disease transient hypoplastic left colon syndrome etc.
Heart defects. There are a number of cardiac anomalies that can occur, the most common is hypertrophic cardiomyopathy.

Related Questions

What are the most common congenital abnormality for the baby in diabetic pregnancy?

VSD. Cardiac ventricular septal defect (hole in the heart, congenital heart murmur) is one of the most common congenital anomalies in general and the most frequent anomaly in infant of pregestational diabetic mothers. More specific anomalies to diabetic infants include caudal regression and renal anomalies.