In the lab: Adverse pregnancy outcomes studied

Ganesh Thippeswamy

A study linking high blood sugar levels with pregnancy complications will result in more women diagnosed with gestational diabetes mellitus, a form of diabetes occurring only during pregnancy.

A multinational group of experts including three Northwestern scientists co-authored the Hyperglycemia and Adverse Pregnancy Outcomes experiment. The study tested more than 25,000 pregnant women across nine countries.

“(The experiment) showed that existing diagnostic criteria may leave out many women and babies at risk of health complications due to GDM,” said NU Prof. Lynn Lowe, the study’s project manager.

Elevated blood sugar levels during pregnancy, a hallmark symptom of gestational diabetes, present dangers to the mother and her unborn baby, said lead author Dr. Boyd Metzger, a professor of metabolism and nutrition at NU’s Feinberg School of Medicine.

These blood sugar levels don’t need to be as high as once thought for complications to arise, Lynn Lowe said.

These results led the panel of scientists to recommend changes to the diagnostic criteria. Imposing stricter criteria is in the patients’ best interests, and expectant females can seek treatment early to minimize risks to both themselves and their babies, Metzger said.

“Women with gestational diabetes are at increased risk of having a pregnancy complicated by high blood pressure or requiring a Cesarean section for delivery of their baby,” said Prof. Dr. William Lowe, a co-investigator on the study. “Women who are diagnosed with gestational diabetes are at increased risk for developing type 2 diabetes later in life.”

William Lowe added that mothers with gestational diabetes pass risks on to their babies, such as an increased likelihood of the baby being overweight and developing type 2 diabetes later in life.

Environmental and genetic factors also play a part in the development of the disease.

“We have no control over our genetic make-up, but it is known that women who are overweight prior to pregnancy are at increased risk of developing gestational diabetes,” William Lowe said. “Maintaining a normal body weight prior to pregnancy is one of the most important things that a woman can do to decrease her risk of developing the disease.”

Women are diagnosed using an oral glucose-tolerance test, which measures a patient’s blood sugar levels when fasting and one and two hours after drinking a sugary glucose drink. Under the old requirements, patients who presented with higher-than-normal blood glucose levels at two or three of these checkpoints were diagnosed with GDM. The policy has been amended so patients only need to exhibit heightened levels at one measurement.

These revised requirements could lead to a doubling or tripling of the number of cases in the future, Lynn Lowe said.

“Whereas approximately 5 to 8 percent of pregnant women were previously diagnosed with GDM, 16 percent may now meet the criteria for GDM,” she said.[email protected]