Pregnancy is associated with many physiologic and hormonal changes along with changes in sleep architecture, placing pregnant women at risk for the development of sleep-disordered breathing or worsening of preexisting sleep apnea. Snoring, the most common symptom of sleep apnea, is markedly increased during pregnancy. The apneic episodes are commonly associated with oxygen desaturations, the combination of obstructive sleep apnea and pregnancy can be potentially harmful to the fetus given the low oxygen reserves during pregnancy.
Obstructive sleep apnea has been associated with an increased risk of hypertension among the general population, and this raises the possibility of its association with gestational hypertension and preeclampsia.
most suggestive of OSA include habitual snoring, witnessed apneas, gasping and choking sensations during sleep, large neck (>16 inches in a woman of normal height), and hypertension. During the day, patients often complain of nonrefreshing sleep, excessive daytime sleepiness, fatigue, impaired concentration, and personality changes.
Physiologic changes of pregnancy, including progressive weight gain and upward displacement of the diaphragm, may predispose women to OSA. Estrogen and progesterone levels rise significantly during the course of pregnancy. Estrogen induces hyperemia, nasopharyngeal mucosal edema, and vasomotor rhinitis, which can lead to a narrowing of the upper airway with increased resistance to airflow. Nasal obstruction, especially chronic nocturnal nasal congestion, has been shown to be an independent risk factor for SDB in the general adult population. Reduced upper airway dimensions, which is a risk factor for sleep apnea has been demonstrated among women in the third trimester of pregnancy.