TUESDAY, May 22, 2007 (HealthDay News) -- Sleep apnea greatly increases the risk of diabetes and high blood pressure during pregnancy, according to a U.S. study that looked at nationwide data on millions of pregnancies in 2003.
Sleep apnea is a nighttime breathing disorder that disrupts sleep, causing multiple awakenings. Obesity is a major risk factor for sleep apnea.
Out of almost 4 million deliveries, 452 women had sleep apnea. Of the almost 168,000 women with gestational diabetes, 67 had sleep apnea. Of the almost 201,000 women with pregnancy-induced high blood pressure, 166 had sleep apnea.
The researchers concluded that sleep apnea was associated with a twofold increase in the risk of gestational diabetes and a fourfold increase in the risk of pregnancy-induced high blood pressure.
The findings were to be presented Tuesday at the American Thoracic Society's international conference in San Francisco.
"The repetitive decrease in oxygen that occurs during the night in someone with sleep apnea heightens the body's 'fight or flight' state, which can raise blood pressure," researcher Hatim Youssef of the Robert Wood Johnson Medical School at the University of Medicine & Dentistry of New Jersey, said in a prepared statement.
"The body also secretes more hormones such as cortisol and epinephrine, and the body responds by producing more glucose coupled with a decreased sensitivity to insulin, which can lead to diabetes," Youssef explained.
He noted that pregnancy can worsen sleep apnea, particularly during the third trimester when weight gain is the greatest.
"When a mother's oxygen level drops at night, it may also affect the oxygen level of the fetus, and we don't know what the long-term effects are," Youssef said. "That's why it's important for a pregnant woman with sleep apnea to be treated with CPAP (continuous positive airway pressure) during her pregnancy."
CPAP delivers air through a mask while a person sleeps.
The U.S. National Heart, Lung, and Blood Institute has more about sleep apnea.