Elevated blood glucose during pregnancy can increase a woman’s risk of developing Type II diabetes in the future. It also increases risks for her unborn child.
Insulin is a hormone secreted by the pancreas that helps to maintain appropriate levels of blood glucose. Resistance to the effects of insulin can develop, resulting in elevated blood sugar. Gestational diabetes mellitus (GDM) is glucose intolerance that is first detected during pregnancy. One of the changes in maternal metabolism is a change in insulin sensitivity, as much as 70% in women who exhibit GDM.
Effects of Gestational Diabetes
Women who develop GDM during pregnancy are at high risk of developing Type II diabetes and cardiovascular disease post-partum. During pregnancy, women with GDM are at a higher risk of developing hypertension and pre-eclampsia. Even abnormalities in glucose tolerance during pregnancy that do not constitute GDM correlate with increased risk for pre-diabetes, diabetes and heart disease.
GDM increases the risk of macrosemia, also known as Big Baby Syndrome. High levels of glucose, insulin and insulin-like growth factor (IGF) stimulate the growth of the fetus. Large-for-gestational-age (LGA) babies can cause birth difficulties such as maternal hemorrhage, requiring delivery by Cesarean section.
Although LGA babies are large, their health is often delicate, leading to the moniker “fragile giants.” This is in part because they tend to be born prematurely due to their large size. The excessive size results from excess deposition of subcutaneous fat rather than lean tissue. High levels of serum insulin (hyperinsulinemia) are common.
Macrosemia occurs in 50% of pregnancies complicated by insulin-dependent diabetes mellitus. Mild to moderate mental retardation can occur in LGA babies. Abnormally high birth weight is associated with increased risk of perinatal mortality. At delivery, fragile giants are more likely to experience traumatic injury, shoulder dystocia and asphyxia.
Diagnosis, Prevention and Treatment of Gestational Diabetes
Fasting blood glucose tests in women with a history of GDM have been found insufficiently sensitive to diagnose Type II diabetes. Thus, it is recommended that oral glucose tolerance testing (OGTT) be carried out on pregnant women in order to identify and effectively treat GDM.
The best way to prevent the development of GDM (and Type II diabetes later in life) is to normalize blood sugar levels and maintain a healthy weight before and during pregnancy. This will also benefit the fetus, as maternal obesity and excessive weight gain correlate with the incidence of macrosemia. Serum glucose during pregnancy can be managed through a low-carbohydrate diet, or by insulin injections or oral medication.