Insomnia and sleep apnea can lead to premature births, researchers report, a fact that augments the prevalence of serious health-related issues in preterm babies, including cerebral palsy (CP).
The study, “Sleep Disorder Diagnosis During Pregnancy and Risk of Preterm Birth,” was published in the journal Obstetrics and Gynecology.
Premature births — those that occur before the 37th week of pregnancy — are still a major problem worldwide. Pregnant women normally give birth at about 40 weeks.
About 15 million premature babies are born in the world every year, and they are at increased risk of death from birth-related complications. Beyond cerebral palsy, preterm children can be born with developmental disabilities, hearing impairments, and other health problems, often because they haven’t fully developed in the womb.
Sleep disorders like insomnia or sleep apnea have been suggested as being linked to an increased risk of preterm birth. As a result, public health efforts have been working on better therapies for pregnant women with serious sleep disorders, as these could save babies’ lives while avoiding the use of medication.
Now, an analysis of a large pool of three million pregnant women from 2007 to 2012 in California showed that better sleep can indeed minimize the number of premature births.
Researchers analyzed anonymous records containing the women’s medical histories and information collected throughout their pregnancies, along with the delivery of their babies. About 2,300 women from the records analysis had been diagnosed with a sleep disorder during their pregnancy. Insomnia and sleep apnea were the most frequent problems, although excessive sleepiness, narcolepsy, and restless leg syndrome were also noted.
Insomnia was found to increase the risk of preterm birth by 30 percent, while sleep apnea increased it by 40 percent. The risk of very premature births due to sleep disorders was also observed, with 5.3 percent of the women analyzed giving birth before 34 weeks, compared to 2.9 percent for women without sleep disorders.
“It seems obvious, but strangely this study has not been done before,” Laura Jelliffe-Pawlowski, PhD, an epidemiologist at the University of California, San Francisco (UCSF), and one of the study’s authors, said in an article written by Amy Maxmen published in the journal Nature. “Seeing this relationship is important because we are just starved for interventions that can make a difference.”
The real numbers of sleep disorders is unknown because pregnant women often go undiagnosed, according to a UCSF press release.
According to the release, researchers were surprised by how few women in the study — “well below 1 percent” — had a sleep disorder, “and suspect that only the most serious cases were identified.”
“The women who had a diagnosis of a sleep disorder recorded in their medical record most likely had more severe presentations,” said Aric Prather, PhD, assistant professor of psychiatry at UCSF and senior author of the study. “It’s likely that the prevalence would be much higher if more women were screened for sleep disorders during pregnancy.”
The study is part of the $100 million UCSF Preterm Birth Initiative to study premature births, focusing on California and East Africa. The scientists hope to identify medical and social approaches that could reduce preterm births and evaluate their methods in clinical trials with pregnant women. The initiative is funded by the Bill and Melinda Gates Foundation and Lynne and Marc Benioff.
Jennifer Felder, PhD, the study’s first author and a postdoctoral researcher in clinical psychology, said that although insomnia is unlikely to be a direct cause of early births, it could trigger processes such as inflammation, which eventually lead to prematurity.
As a result of the study, UCSF researchers will now examine proteins involved in the immune response in pregnant women, analyzing premature birth and insomnia.
In the meantime, the results from the analysis of the birth records could help alert doctors to potential danger.
“I counsel women on how to have the best pregnancy outcome,” said Louis Muglia, an MD and PhD, and the director of the Center for Prevention of Preterm Birth at Cincinnati Children’s Hospital Medical Center in Ohio. “Now I might start asking, ‘do you get a good night’s sleep?'”