It's no secret that pregnancy can affect women's sleep. But some kinds of sleep disturbances can be dangerous to her unborn baby. Seeking treatment may help. A recent study looked at the effect of treating abnormal breathing during sleep in women with pre-eclampsia.
Pre-eclampsia is a condition where the woman has sustained high blood pressure and protein in her urine.
It is a dangerous condition for the mother and baby if not treated, but the only currently known treatment is to deliver the baby. It affects 5 to 7 percent of pregnant women.
This study found that treating the sleep-breathing issues in the women appeared to improve the unborn baby's health as well.
The study, led by Diane M. Blyton, PhD, from the University of Sydney in Australia, looked at the effects of treating sleep-disordered breathing on pregnant women's unborn babies. Sleep-disordered breathing is abnormal breathing during sleep and is common among women with pre-eclampsia. The study involved three parts.
The researchers first measured how frequently the unborn babies moved during sleep in the third trimester of 20 pregnant women with normal pregnancies. This measurement is called fetal movement. Fetal movement is a marker of how healthy the unborn baby, or fetus, is.
Then, the researchers recruited 20 pregnant women who had pre-eclampsia and 20 pregnant women who were healthy and without pre-eclampsia. All were in their third trimester.
The researchers measured the fetal movement in these 40 women while they slept overnight. During this experiment, 68 percent of women with pre-eclampsia experienced limitations in their breathing overnight, compared to 19 percent of the women without pre-eclampsia.
Finally, the researchers measured the fetal movement overnight in 10 women with pre-eclampsia during two nights. On the first night, the women received no treatment.
On the second night, the women wore masks that delivered continuous positive airway pressure (CPAP). CPAP is a common treatment for sleep apnea, a type of sleep-disordered breathing in which a person frequently stops breathing for ten seconds or more during the night. CPAP delivers pressured air into a woman's nasal cavity to help keep the airways open during sleep.
The researchers found that babies of the women with pre-eclampsia had an average of 319 fetal movements during the night. The healthy pregnant women's unborn babies had an average 689 fetal movements during the night.
This difference indicated potentially healthier babies in the healthy pregnant women than in those with pre-eclampsia. The babies of the women with pre-eclampsia also had fewer hiccups than the other babies.
In fact, only the babies of two of the women with pre-eclampsia had fetal hiccups, compared to 17 of the women (85 percent) without pre-eclampsia. Having hiccups is healthy for unborn babies.
However, treatment with CPAP made a difference. In the 10 women who received the overnight CPAP treatment, the number of fetal movements increased to an average of 592.
When the 10 women with pre-eclampsia did not receive CPAP treatment, their babies' movements decreased during the night by 7.4 movements per hour. When they slept while using CPAP, these women's babies moved more often as the night went on, increasing by 12.6 movements per hour.
The women's babies also had many more hiccups (total of 95 hiccups) on the night the women used CPAP compared to the night they didn't (total of 12 hiccups).
Overall, the researchers established that the babies of women with pre-eclampsia did not have as many fetal movements or hiccups during the night as those of healthy pregnant women did. However, treatment with CPAP may help close the gap and may improve the baby's health.
According to William Kohler, MD, the director of the Florida Sleep Institute in Spring Hill, Florida, and a dailyRx expert, past studies have already shown that using CPAP can improve pre-eclampsia in mothers.
"This particular study is very important in that it objectively shows adverse effects on the fetus and improvement in fetal activity with CPAP in mothers with pre-eclampsia," Dr. Kohler said.
The study was published in the January issue of the journal Sleep. The research was funded through the National Health and Medical Research Council of Australia Career Development Fellowship awarded to one of the authors, Dr. Michael Skilton.
A different author, Dr. Colin Sullivan, co-founded the company ResMed, which sells CPAP equipment, and still owns stock in the company. He is also the director of a start-up company that is working to develop diagnostic sleep technology.