Each year, between 4 percent and 8 percent of all pregnant women in the United States are diagnosed with gestational diabetes. The condition is found in women who have never had diabetes but whose blood sugar, or glucose, levels are elevated during pregnancy.

Eight percent doesn’t sound like a lot. But double or triple that percentage, and all of a sudden it starts to sound like an epidemic.

That’s what very well may happen, now that the American Diabetes Association has adopted new diagnostic criteria it’s hoping physicians will use.

For the first time in nearly 50 years, the blood glucose level cutoff that identifies a woman as having gestational diabetes has changed. Women who otherwise were believed to be healthy because their blood glucose levels were within the normal range might actually have had gestational diabetes and not even known it. That puts them at risk for developing Type 2 diabetes in the future.

And their children? They are at a greater risk for becoming obese and developing diabetes as well.

The movement to revisit the criteria for diagnosing gestational diabetes began to gain momentum a decade ago, said Dr. Patrick Catalano, who heads the department of obstetrics and gynecology at MetroHealth Medical Center.

“When the original criteria was formulated, [physicians] were really looking at the long-term risk to the mother,” he said. Less emphasized was concern for the newborn.

The first real push for new benchmarks came in 2008 after the results of a study looking at birth outcomes of more than 25,000 women was published in the New England Journal of Medicine.

MetroHealth was one of 15 centers in nine countries to participate in the Hyperglycemia and Adverse Pregnancy Outcomes, or HAPO, study that appeared in the journal. It analyzed the results of patients’ glucose-tolerance tests given at the start of the third trimester.

Among the outcomes researchers observed were increased instances of: cesarean section delivery in first-time moms, pre-term delivery and pre-eclampsia (high blood pressure) in women whose glucose levels signaled gestational diabetes and in women whose glucose levels were considered normal.

“There was a very linear relationship between the mother’s glucose level and pregnancy outcomes,” Catalano said.

Those outcomes extended to the babies, who were more likely to weigh more. In general, the babies also can be at risk of having health issues serious enough to be placed in neonatal intensive care or for developing diabetes later.

In 2008, the International Association of Diabetes and Pregnancy Study Groups, using the HAPO study and the results of other research on gestational diabetes as a reference point, sponsored a meeting whose mission was to come up with uniform criteria for determining gestational diabetes.

Catalano was part of the group’s writing committee that composed the new criteria.

Those criteria were recently put to the test by researchers at the New Jersey-based company Quest Diagnostics, which analyzed lab results from more than 900,000 pregnant women. They found the number of women diagnosed with gestational diabetes would have nearly doubled had the new screening criteria been in place.

Those results were published in the Dec. 20 journal Obstetrics & Gynecology.

The analysis also showed that most women with gestational diabetes are never given follow-up screening for Type 2 diabetes after their baby is born, even though current medical guidelines recommend it.

“We’re now going to see some real consensus on how we should be screening women, the definitions that everyone should be using,” said Dr. Jon Nakamoto, medical director for Quest Diagnostics. “I think this paper will underscore the importance of getting this discussion moving.”

If you’re pregnant, the odds are high that you will be tested for gestational diabetes at least once. Why not have a conversation with your OB-GYN early on in your pregnancy about how soon you should be screened, especially if you have any risk factors: older than 25, a member of an ethnic group other than Caucasian, overweight or family history of diabetes.

After all, the sooner you find out whether you are on a path leading toward Type 2 diabetes, the quicker you can start working on getting healthier and changing course.