Severe apnea can present fetal threat.(News)

DENVER -- Obstructive sleep apnea is far more common during pregnancy than most physicians realize and in its more severe forms can jeopardize the fetus, Meir H. Kryger, M.D., said at a satellite symposium held in conjunction with the annual meeting of the Associated Professional Sleep Societies.

"I've had cases of sleep apnea in pregnant women who actually before diagnosis had several spontaneous abortions. I have no doubt that in some cases the baby was lost when it became very, very hypoxic," added Dr. Kryger, professor of medicine and director of the sleep disorders center at the University of Manitoba, Winnipeg.

The treatment for obstructive sleep apnea in pregnancy is continuous positive airway pressure (CPAP). It's considered safe for both mother and fetus.

The prevalence of habitual snoring--that is, snoring nearly every night--climbs from 4% in nonpregnant women to 14%-23% during pregnancy. The increase during pregnancy is believed to be due to weight gain coupled with hormonally induced changes in the elasticity of the pharyngeal airway and other tissues.

"Sleep apnea is actually quite common in pregnant women. I don't know why more doctors don't pick it up," Dr. Kryger said. "Obstetricians, I think, need to learn a great deal more about sleep and its problems."

He advises routinely performing polysomnography in pregnant heavy snorers (especially if they are also observed to stop breathing), treating with CPAP those who meet the criteria for obstructive sleep apnea, and repeating the sleep lab testing post partum. The reason he advocates an aggressive approach is the documented adverse effects of heavy snoring in pregnancy. He pointed to a Swedish study conducted several years ago highlighting the implications of heavy snoring during pregnancy.

The study by Karl A. Franklin, M.D., Ph.D., a pulmonologist at University Hospital, Umea, and his coworkers involved 113 habitual snorers and 289 infrequent or nonsnorers. All had singleton pregnancies. On their delivery day, they and their partners completed a questionnaire on snoring, daytime tiredness, and witnessed sleep apneas.