Maternal diabetes can cause a number of health issues for a fetus. For example, congenital heart disease (CHD) is one of the most common birth defects for infants.
Gestational and maternal diabetes are not the same thing. While gestational diabetes happens during pregnancy and usually goes away after the pregnancy, maternal diabetes is when the mother already has diabetes prior to getting pregnant, or develops diabetes while pregnant.
Birth defects are typically labeled genetic or non-genetic (due to “environmental” factors) in infants. CHD is more complicated and is a mixture of both genetic and non-genetic. An example of an environmental factor is maternal hyperglycemia, or maternal diabetes.
Studies have shown that there is a significant correlation between maternal diabetes and an increased risk of CHD in infants. Dr. Vidu Garg, the director of the Center for Cardiovascular Research Institute says, “And many factors, including the type of diabetes, other environmental influences, and potentially certain genetic predispositions can influence which CHD subtypes are likely to develop.”
Researchers from previous studies have found that the infants born to mothers with type 1 diabetes were more likely to suffer from heart malformations and atrioventricular septal deficiency in the heart. The infants with the highest risk of heterotaxy, a condition where the internal organs are not arranged properly, are those born to mothers with type 2 diabetes.
Both type 1 and 2 in the mother increases the chance of CHD in infants significantly.
Researchers found that the exposure age of the fetus for maternal diabetes is important. Before conception and during the first trimester are crucial times for the fetus. If diabetic embryopathy, or a defect in the fetus, is introduced in this time period, it is more likely to affect the heart and vessels.
If the mother develops diabetes later in the pregnancy, it is more often associated with fetal macrosomia, or an increased risk of newborn complications. This showed an increase in complications and mortality in the baby.
Why does maternal hyperglycemia cause birth defects? This is something that researchers have yet to figure out.
Researchers plan to continue their studies to better understand and reduce the risk of CHD in infants in the future.
The goal of researchers is to find a way to screen mothers who have environmental risks.