A Threat to Both Mom and Her Baby

Gestational diabetes is on the rise, and experts are worried.

Video: What Is Diabetes?

Amid all the hand-wringing over the explosion of diabetes in America, the spread of the temporary type that afflicts pregnant women has gotten scant attention. While no one has kept close track nationally, experts think as many as 8 percent of women now develop diabetes during pregnancy—perhaps twice the percentage of a decade or two ago.

The trend has experts worried. Women with gestational diabetes have a much elevated chance of developing type 2 diabetes later on—and if it’s left untreated, the condition nearly doubles the risk that the child will become obese and thus at higher risk for type 2 diabetes, too. "We’re seeing young girls with a metabolic state at [age] 20 that you’d normally see in a 40-year-old," says Lois Jovanovic, CEO and chief scientific officer at the Sansum Diabetes Research Institute in Santa Barbara, Calif. But aggressive management of blood sugar levels, through diet and exercise—and insulin if necessary—can reduce the risks for both mother and child.

Gestational diabetes, like the chronic disease, is characterized by too much glucose in the bloodstream—which, over time, can lead to heart and vascular problems, kidney failure, and blindness, among other complications. In type 1 diabetes, the pancreas doesn’t produce insulin, which helps move glucose out of the blood and into cells to be used for energy. With type 2 diabetes, the body becomes desensitized or resistant to insulin’s effect. Some 20 million people now have type 2 diabetes; by 2050, their numbers are expected to reach more than 48 million. During pregnancy, hormones produced by the placenta to help the baby develop block the effect of insulin in some women. Moms-to-be who were overweight before conceiving are at higher risk, because obesity also causes insulin resistance.

The condition is more common among people in certain ethnic groups, including Hispanic Americans, American Indians, and African-Americans. But all women over age 25 are at elevated risk. Thin and Caucasian, Julie Rottenberg, 37, was in her 28th week of pregnancy when she got her diagnosis about a month ago. Subbing chicken and vegetables for her beloved bagels and chocolate didn’t budge her glucose levels, though her "taste buds are in a state of shock," she says. So now Rottenberg is adding a nightly insulin shot.

No picnic. Gestational diabetes is no picnic for either mother or child. Women who develop it once are highly likely to do so again in subsequent pregnancies, and worse, they have up to a 50 percent chance of developing type 2 diabetes in five to 10 years. In as many asthird of women, the condition persists after delivery.

Meantime, all the extra glucose circulating in a woman’s body essentially overfeeds her baby, who stores the extra energy as fat. Big babies weighing more than 9 pounds are harder to deliver and may experience damage to their shoulders during birth. Because they’ve been making extra insulin to rid themselves of mom’s blood sugar, they may be born with extremely low blood glucose levels and need some extra monitoring. They are also at higher risk for breathing problems because of delayed lung development and may have jaundice. "It can mean more heel sticks" and a stay in the neonatal intensive care unit, says Carol Levy, an assistant professor of clinical medicine at New York-Presbyterian/Weill Cornell Medical Center.

The problems don’t stop there. A study published in September found that babies born to women with untreated gestational diabetes were nearly twice as likely to be obese at ages 5 to 7 as those born to women who were successfully treated, putting them at risk for obesity in adulthood. But children of the women whose glucose levels were well managed were no more likely to be obese than women with normal pregnancies. "These kids have a fighting chance for a normal metabolism," says Teresa Hillier, an endocrinologist at the Kaiser Permanente Center for Health Research and the study’s lead author.

Screening is a key to making that happen. The average woman can expect to be screened between the 24th and 28th weeks of pregnancy, but a woman who’s at high risk because of obesity, a family history of diabetes, or previous gestational diabetes herself should be tested as soon after conceiving as possible; untreated diabetes can cause birth defects during the first trimester. Blood glucose levels are typically measured one hour after the woman quaffs a special sugary drink. If they exceed 140 milligrams per deciliter, she’ll be retested using a more precise blood test. A second positive means gestational diabetes.