Exploring Fetal Sex as a Risk Factor for Sleep Disordered Breathing and Its Complications in Pregnancy.

Sleep disordered breathing (SDB) is a common, yet under-recognized and undertreated condition in pregnancy. Sleep disordered breathing is associated with pregnancy complications including preeclampsia, gestational diabetes, preterm birth, as well as severe maternal morbidity and mortality. The identification of risk factors for SDB in pregnancy may improve screening, diagnosis, and treatment of SDB prior to the onset of pregnancy complications. The goal of this study was to determine whether fetal sex increases risk of SDB in pregnancy. A cohort of singleton (N = 991) pregnant women were recruited within 24 to 48 hours of delivery and answered questions regarding SDB symptoms by questionnaire. Women who reported frequent loud snoring at least 3 times a week were considered to have SDB. Hospital records were reviewed to extract information on fetal sex and pregnancy complications including preeclampsia, pregnancy-induced hypertension, gestational diabetes, preterm delivery, and low birth weight. Women carrying male fetuses were significantly more likely to have SDB (β = .37, P = .01, OR: 1.45 [95% CI: 1.09-1.94]). Fetal sex was associated with increased risk of hypertensive disorders of pregnancy (defined as preeclampsia and/or pregnancy-induced hypertension) among women with SDB in pregnancy (β = .41, P = .02, OR: 1.51[95%CI:1.08-2.11]).Fetal sex did not increase risk of preterm birth, low birth weight, or gestational diabetes among women with SDB in pregnancy. Women carrying male fetuses were approximately 1.5 times more likely to report SDB in pregnancy compared to women carrying female fetuses, and women with pregnancy-onset SDB carrying male fetuses were 1.5 times more likely to have hypertensive disorders of pregnancy compared to women with SDB carrying female fetuses. Confirmation of fetal sex as a risk factor may, with other risk factors, play a role in identifying women at highest risk of SDB complications in pregnancy.