Background Pre-existing maternal diabetes is associated with a five-fold increase in the prevalence of congenital cardiovascular malformation (CVM). NICE guidelines recommend that pregnant women with diabetes should be offered antenatal examination of the four-chamber view of the fetal heart and outflow tracts at 18–20 weeks to detect congenital malformations.

Aim The primary objectives of the audit were to find out the prevalence of CVM in infants of diabetic mothers and the success rate of fetal-echocardiography in diagnosing CVM antenatally. Our secondary objectives were to find out the number of diabetic mothers booked for delivery at the Sunderland Royal Hospital and the percentage of diabetic pregnancies referred for antenatal cardiac screening.

Methods This was a retrospective audit. Data was collected from all diabetic mothers booked for antenatal care between April 2004 and December 2008 and the corresponding cohort of infants with cardiovascular malformations born between May 2004 and May 2010.

Results 89% of the 102 diabetic mothers had undergone antenatal cardiac screening. 180 infants were born with CVM during the study period (1.09% of total births). Of these, five infants were born to diabetic mothers (4.9%). Fetal echocardiogram gave the correct diagnosis in 96.7% of the cases with a specificity of 100% and a sensitivity of 25%.

Conclusions 89% of the diabetic mothers had undergone antenatal cardiac screening. Maternal diabetes is associated with 4.9% risk of CVM. VSD is the most common CVM in maternal diabetes. Fetal echocardiogram gave the correct diagnosis in 96.7% of the cases.