Study shows link between sleep apnea and hospital maternal deaths

Pregnant women with obstructive sleep apnea are more than five times as likely to die in the hospital than those without the sleep disorder, a comprehensive national study by University of South Florida researchers found.
Among delivery-related hospital discharges, sleep apnea was also associated with an increase in severe medical conditions that are top causes of maternal death, including pre-eclampsia, eclampsia, an enlarged heart and pulmonary blood clots.
Dr. Judette Louis, assistant professor of obstetrics and gynaecology at the USF Health Morsani College of Medicine, led the large-scale national study appearing in the journal SLEEP. She specialises in maternal-foetal medicine, working out of Tampa General Hospital.
Sleep apnea causes repeated awakenings and pauses in breathing during the night. Previous smaller studies have found that the condition increases the risk for poor pregnancy outcomes, including pre-eclampsia (high blood pressure in pregnancy associated with loss of protein in the urine), restricted growth of the foetus, preterm delivery and gestational diabetes. Obesity appears to contribute to the adverse effects.
However, the USF study provided the first large-scale U.S. analysis of the association between sleep apnea and maternal deaths.
‘The astounding association with maternal death was surprising,’ said lead author Judette Louis, MD, MPH, assistant professor of obstetrics and gynaecology at the USF Health Morsani College of Medicine who works out of Tampa General Hospital. ‘I did not expect to find such a difference in mortality between pregnant women who had sleep apnea and those who did not, especially when we controlled for obesity and other complicating factors.
While more study is needed, the increased likelihood of death for those with sleep apnea may be explained in part by the physiological demands of pregnancy, she said. ‘Underlying damage or chronic disease caused by sleep apnea may be exacerbated by the stresses of pregnancy.’
Maternal death rates have increased slightly in recent years, and obesity is one suspected reason.
‘Our study indicates that sleep apnea may also play a role, whether a woman is obese or not,’ said Dr. Louis, who holds a joint appointment in the USF College of Public Health