According to studies funded by the National Institutes of Health,  Snoring , older age and obesity may increase a pregnant woman's risk for sleep apnea or interrupted breathing during sleep. The study was published in the  American Journal of Obstetrics and Gynecology.

"Our study found an easy, inexpensive way to screen large numbers of women at higher risk of sleep apnea during pregnancy," said study co-author Uma Reddy

"Right now, this means we will be able to quickly identify women who may benefit from further testing . Depending on what we learn from future studies, our findings could also lead to improvements in pregnancy outcomes."

In an earlier study of first-time pregnancies , the found that sleep apnea increases a woman's risk for hypertensive disorders and gestational diabetes.

Currently, there are no medical guidelines or treatment recommendations for sleep apnea during pregnancy. NIH currently supports a study of potential treatments for pregnancy-related sleep apnea and is planning a larger one to be conducted by the NICHD-funded Maternal-Fetal Medicine Units Network.

In the current study, participants responded to questionnaires about their sleep habits , snoring, and daytime sleepiness in early pregnancy (6 to 15 weeks) and mid-pregnancy (22 to 29 weeks). The women also underwent sleep apnea testing using an at-home monitoring device.

The researchers found that 3.6% of 3,264 women in early pregnancy and 8.3% of 2,512 women in mid-pregnancy had sleep apnea. Risk factors for having the condition included frequent snoring (three or more nights per week), older maternal age, and being overweight or obese as determined by body mass index ( BMI ).

Because each woman's risk varies according to individual characteristics, the authors developed a calculator using maternal age, BMI, and frequency of snoring to arrive at her probability of sleep apnea in early and mid-pregnancy.

This tool may be used by obstetric providers to identify women at risk for the condition, so they can be referred to for definitive testing.

A common treatment for sleep apnea is continuous positive airway pressure ( CPAP ) therapy, which involves wearing a mask that fits over the nose or the nose and mouth. Air is pumped through a wire attached to the mask, increasing pressure into the airways to keep them from collapsing.

Dr. Reddy explained, however, that it is not known if CPAP therapy during pregnancy will prevent hypertension, diabetes or other apnea. She has sleep apnea should discuss her concerns with a doctor.