Issue 176 Item 6 Increased Risk of Cardiovascular Defects for Babies of Diabetic

Babies born to mothers who have diabetes have a significantly increased risk of cardiovascular malformations, according to recent British report.

Congenital cardiovascular malformations form the most prevalent group of birth defects, but the cause is unknown for most cases, writes Christopher Wren, MD, of Freeman Hospital, Newcastle upon Tyne. Maternal diabetes is known to have a teratogenic effect on the cardiovascular system and has been suggested as a cause of this class of defects. However, a prospective population study of live born infants of diabetic mothers has not been previously reported.

To address this issue, investigators led by Dr Wren performed a study to determine the prevalence at live birth of structural cardiovascular malformations in babies born to mothers with diabetes compared to those born to non-diabetic mothers. The study population included 192,618 live births during 1995-2000 in the former Northern Health Region of England. Of these, 192,009 babies were born to non-diabetic mothers and 609 were born to diabetics.

Based on a records examination of reported cardiovascular defects within the study population, the researchers found a five-fold greater risk for infants born to diabetic mothers (95% confidence interval, 3.3-7.8). Cardiovascular malformations were reported in 3.6% (22 of 609) babies born to diabetic mothers, compared to only 0.74% (1417 of 192,009) of those born to non-diabetics.

The investigators examined the spectrum of cardiovascular defects in this population together with data from previous reports and found that transposition of the great arteries, tricuspid atresia, and truncus arteriosus are seen at least 3 times more frequently than expected in the infants of diabetic mothers.

"Our prospective population based study of infants of diabetic mothers has confirmed the increased risk of cardiovascular malformations and the greatly increased risk of some specific malformations," concludes Dr. Wren. The researchers support existing recommendations that all pregnant women with diabetes should be offered a specialist foetal echocardiogram. Heart 2003 Oct;89:10:1217-20

DID YOU KNOW:
Continuous infusion of glucagon-like peptide (GLP-1) successfully maintained glycemic control in elderly patients who were previously controlled on oral hypoglycemic agents, according to the results of a study published in the October issue of Diabetes Care. The treatment group had fewer hypoglycemic events, greater insulin release in response to glucose, and greater rate of glucose disposal.