Sleep-disordered breathing

Sleep-disordered breathing includes the spectrum of snoring, upper airway resistance syndrome, and obstructive sleep apnoea and hypopnoea syndrome. It is assessed using the Epworth sleepi­ness scale and sleep studies measuring transcutaneous PCO2 and apnoeic/hypopnoeic episodes.

Maternal obesity together with the physiological changes of preg­nancy discussed previously predispose to the development of sleep disordered breathing (42). Since nasal obstruction is a risk factor for snoring and sleep-disordered breathing in the general popula­tion, it is possible that the nasal hyperaemia and rhinitis of preg­nancy increase the risk in pregnancy. Upper airway size at the oropharyngeal junction is also reduced in pregnancy and especially in pre-eclampsia. However, because women in the second half of pregnancy sleep in the lateral position and spend less time in rapid eye movement sleep they are less prone to apnoeic and hypopnoeic events. The risk is also lower because of the respiratory stimulatory effect of progesterone (43).

Continuous positive airway pressure is the treatment of choice of sleep-disordered breathing in the general population and can be safely and effectively used in pregnancy. Women should be advised to limit weight gain. Continuous positive airway pressure has been associated with lower nocturnal blood pressure measurements in patients with preeclampsia (44). Sleep-disordered breathing may improve after delivery.