SAN FRANCISCO — Pregnant women were more likely to have risk factors for obstructive sleep apnea compared with nonpregnant women in a study of 4,564 women.
In addition, pregnant women identified to be at risk for sleep apnea were more likely to develop preeclampsia compared with pregnant women who didn't have sleep apnea risk factors, Dr. Nicole Higgins, an anesthesiologist at Northwestern University, Chicago, and her associates reported in a poster presentation at the annual meeting of the American Society of Anesthesiologists.
Among adult women in general, about 2% have obstructive sleep apnea, a condition characterized by obstruction of the upper airway and episodes of apnea and hypopnea during sleep. The incidence of obstructive sleep apnea in pregnancy has been unknown.
“Obstructive sleep apnea is a condition that we see with a rising incidence because the population, in all honesty, is getting larger,” Dr. Higgins said in an interview, referring to the increasing prevalence of obesity. “That's one of the risk factors for obstructive sleep apnea.” In the prospective study, 33% of 4,074 pregnant women presenting for delivery and 20% of 490 control women presenting for outpatient surgery screened positive on the Berlin Questionnaire, a validated means of identifying patients at increased risk for sleep apnea through questions about snoring and daytime sleepiness.
Statistical analysis found that pregnancy doubled the chance for screening positive on the Berlin Questionnaire, and pregnant women who screened positive on the questionnaire were four times more likely to develop preeclampsia, compared with pregnant women who screened negative. Those who screened positive were significantly shorter, heavier before pregnancy, and heavier during pregnancy than were those with a negative screen.
Previous studies have suggested that sleep-disordered breathing or obstructive sleep apnea may increase the risk for preeclampsia or preterm delivery.
In the current study, there was a significant correlation between a positive Berlin screen and heavier infant weight (3,475 g vs. 3,374 g if the mother screened negative). A positive Berlin screen also correlated significantly with risk for low 1-minute Apgar scores. About 7% of infants born to mothers who screened positive had 1-minute Apgar scores below 7, compared with 6% of infants if the mother screened negative for sleep apnea.
Dr. Higgins is working with colleagues in maternal-fetal medicine to use the Berlin Questionnaire to screen women in the first and third trimesters. Women who screen positive are referred for formal sleep studies, and those diagnosed with obstructive sleep apnea will be followed through pregnancy to assess outcomes, she said.