Women who give birth to bigger-than-average babies are susceptible to developing type 2 diabetes later in life, a new study suggests.
Large-for-gestational age infants are defined as those weighing 8 pounds or more, said lead study author Dr. Kartik Kailas Venkatesh, an assistant professor of epidemiology at Ohio State University.
"In an environment of obesity, women are at a higher risk of having larger babies," he said. "And they are also at a higher risk of developing type 2 diabetes later in life."
Venkatesh said that women who deliver large babies most likely suffer from glucose intolerance that causes high blood sugar during pregnancy.
"Even if you don't have gestational diabetes, there's probably still glucose intolerance that's leading you to have a big baby, and then that's probably leading you to develop type 2 diabetes later in life," he said.
"I think that's something that we need to do more research about, so we can develop better counseling and prevention options for women and their families," Venkatesh added.
For the study, Venkatesh and his colleagues examined data from the Hyperglycemia and Adverse Pregnancy Outcome Follow-up Study. They found that among the 4,025 women who did not have gestational diabetes, 13% still had large infants.
During the 10 to 14 years after giving birth, 20% of all of the women developed prediabetes or diabetes. The rate of women who had prediabetes or diabetes was higher among those who had large babies (25%) than among women who delivered normal (20%) or underweight babies (15%), Venkatesh said.
The finding held even after the researchers took into account risk factors for type 2 diabetes, such as age, obesity, high blood pressure and family history of diabetes.
Venkatesh noted that only 25% of the women who have large babies develop type 2 diabetes. So, even if you have a large infant, you're not doomed to develop diabetes, he said.
The findings were presented Friday at the annual meeting of the Society for Maternal-Fetal Medicine, in San Francisco, and also published recently in the American Journal of Obstetrics & Gynecology.
High blood sugar during pregnancy may contribute to having a large baby, said Dr. Dawnette Lewis, director of the Center for Maternal Health at Northwell Health in Manhasset, N.Y. She was not part of the study, but reviewed the findings.
"We think if mom's blood sugar is high, then that also means that the baby's blood sugar is high," Lewis said. "Then what happens is an increase in the production of insulin to decrease blood sugar, but insulin acts as a growth factor, and so that's why those babies get large."
She said that preventing diabetes starts with screening blood sugar levels both during and after pregnancy.
If a woman's blood sugar is high, Lewis said her diet should be changed to lower carbohydrates, to lower blood sugar.
After giving birth to a large baby, women should have their blood sugar levels monitored to see if they're high.
"These patients should be monitored with something called a continuous glucose monitor, which is inserted subcutaneously and tests the blood sugar every 15 minutes," Lewis advised.
Two weeks of monitoring can indicate if the patient is likely to become diabetic, she said. After that, these women should have their blood sugar levels tested regularly by their primary care doctor.
"Even though they only have a 25% chance of developing type 2 diabetes, they should be screened every year by their primary care physician," Lewis said.
For more on type 2 diabetes, see the American Diabetes Association.
SOURCES: Kartik Kailas Venkatesh, MD, PhD, assistant professor, epidemiology, Ohio State University, Columbus; Dawnette Lewis, MD, MPH, director, Center for Maternal Health, at Northwell Health, Manhasset, N.Y.; Feb. 11, 2023, presentation, Society for Maternal-Fetal Medicine, meeting, San Francisco; American Journal of Obstetrics & Gynecology, January 2023