Snoring Pregnant Women At Higher Risk For Gestational Diabetes

A new study from researchers at the Northwestern University Feinberg School of Medicine has found that women who reported frequent snoring during their pregnancy were more likely to develop gestational diabetes -- a condition than can cause health problems for the mother and baby. The study also found pregnancy increases the likelihood that a woman will snore.

This is the first study to report a link between snoring and gestational diabetes.

For the study, 189 healthy women completed a sleep survey at the time of enrollment (six to 20 weeks gestation) and in the third trimester.

Pregnant women who were frequent snorers had a 14.3 percent chance of developing gestational diabetes, while women who did not snore had a 3.3 percent chance. Even when researchers controlled for other factors that could contribute to gestational diabetes such as body mass index, age, race and ethnicity, frequent snoring was still associated with the disease.

Principal investigator Francesca Facco, M.D., a fellow at Northwestern's Feinberg School, will present her findings at the SLEEP 2009 23rd Annual Meeting of the Associated Professional Sleep Societies June 11.

"Sleep disturbances during pregnancy may negatively affect your cardiovascular system or metabolism," said Facco, who in August will become an assistant professor of obstetrics and gynecology at the Feinberg School and a maternal and fetal medicine physician at Northwestern Memorial Hospital.

"Snoring may be a sign of poor air flow and diminished oxygenation during sleep that can cause a cascade of events in your body," Facco said. "This may activate your sympathetic nervous system, so your blood pressure rises at night. This can also provoke inflammatory and metabolic changes, increasing the risk of diabetes or poor sugar tolerance."

The study also showed more women became frequent snorers as their pregnancies progressed. Early in pregnancy, 11 percent of women in the study reported frequent snoring; by the third trimester, the number rose to 16.5 percent. Frequent snoring was defined as snoring three or more nights a week.

Facco said snoring during pregnancy may be triggered by weight gain and edema (a buildup of fluid), which can increase airway resistance. Exactly how the snoring is linked to gestational diabetes is not yet known.

About 4 percent of pregnant women develop gestational diabetes, a condition in which women without previously diagnosed diabetes develop high blood sugar levels during pregnancy. Babies born to mothers with gestational diabetes are at increased risk of problems such as being large for gestational age, which may lead to delivery complications. These babies may also have low blood sugar levels and are at increased risk of becoming obese or developing impaired sugar tolerance or metabolic syndrome later in life.

While gestational diabetes usually resolves after pregnancy, women who develop it are at higher risk for type 2 diabetes later in life.

Facco said further studies are needed to understand the association between snoring and gestational diabetes and to develop interventions to treat sleep disorders during pregnancy.

"If snoring is bothering a woman who is pregnant, she should seek a consultation with a sleep specialist," Facco said.

In related study, also to be presented at the SLEEP 2009 meeting, Facco found sleep disturbances such as restless legs syndrome and insomnia increase significantly during pregnancy.