Purpose of review: Sleep disturbances are frequent during pregnancy. The spectrum of association between pregnancy and sleep disturbances ranges from an increased incidence of insomnia, nocturnal awakenings, and parasomnias (especially restless legs syndrome) to snoring and excessive sleepiness. These disturbances occur as a result of physiologic, hormonal, and physical changes associated with pregnancy. Although the timing and occurrence of different sleep disorders varies, they are most prevalent during the third trimester. Despite reports of the various sleep problems, the exact nature and incidence of sleep disorders in pregnancy is not known. Given that limitation, we are presenting an up-to-date review of the current understanding of the relation between sleep and pregnancy.
Recent findings: Studies suggest that pregnancy affects sleep in multiple ways. There are hormonal changes, physiologic changes, physical factors, and behavioral changes in a pregnant woman-all of which may affect her sleep. They may affect the duration and quality of sleep and lead to a variety of sleep disorders. Pregnancy may also affect an existing sleep disorder. Particular attention may be given to obese pregnant women who would gain more weight during pregnancy or those who develop hypertensive conditions (eg, preeclampsia). Snoring may be more common in women with preeclampsia and the pressor responses to obstructive respiratory events during sleep may be enhanced in preeclamptic women when compared with those with obstructive sleep apnea alone. Several investigators have suggested that obstructive sleep apnea (OSA) may be common in pregnant women despite the presence of intrinsic mechanisms that seem to be geared towards preventing sleep apnea. However, the exact incidence and prevalence of sleep apnea in pregnant women is uncertain. In addition, it is unclear if criteria that are used to define sleep apnea in the general population should be applied to pregnant women. Further investigations are needed to determine if lower thresholds for management of OSA should be used in pregnant women to prevent harm to the fetus.
Summary: In conclusion, sleep disturbances are common during pregnancy though the full extent of this relation remains undefined. Large, multi-center, prospective studies are needed for better understanding.