An extensive study conducted by the US Centers for Disease Control and Prevention (CDC) has revealed the elevated risk of birth defects in women diagnosed with either type 1 or type 2 diabetes before becoming pregnant.  Children born to diabetic mothers are at three to four times more risk of having a wide array of birth defects than children born to mothers without the disease or to those who develop gestational diabetes during pregnancy.

The National Birth Defects Prevention Study (NBDPS) is the first of its kind to link a woman’s diabetes before pregnancy to birth defects that include oral clefts and disorders of the limbs as well as defects that affect the brain, spine, kidneys, and gastrointestinal tract.  One in every 33 infants in the US is born with some form of birth defect.  Such defects are the main reason many infants do not survive.  Although specific risk factors, such as the mother’s diabetes, can sometimes be linked to a child’s birth defects, the cause of defects remains a mystery in the majority of cases.

Recent studies have linked gestational diabetes to birth defects but a growing body of evidence suggests many of these mothers actually had undiagnosed diabetes before pregnancy, which may have affected fetal health.  Most birth defects caused by diabetes occur within the first three months of pregnancy but gestational diabetes is usually not diagnosed until later in the course of pregnancy.

Adolfo Correa, MD, MPH, PhD, and lead author of the NBDPS report, currently published in the American Journal of Obstetrics and Gynecology, stresses the importance of adequate medical care before conception in order to make pregnancy as healthy and safe as possible for both mother and baby, especially where diabetes and obesity are factors.  Correa is an epidemiologist at the National Center on Birth Defects and Developmental Disabilities, a branch of the CDC.

Women who are overweight are most likely to develop gestational diabetes, which increases the risk of developing type 2 diabetes at a later time in the woman’s life.  Gestational diabetes is on the rise in the US, where about 7%, or 200,000 cases annually, involve this form of diabetes.

The NBDPS involves nine US medical centers specializing in birth defects.  Researchers have amassed data from 30,000+ cases of birth defects and are analyzing it to identify any potential causes for birth defects.

Source: CDC