Women who experience sleep disorders such as insomnia and apnea during pregnancy may be more likely to give birth prematurely than pregnant women who do not have trouble sleeping, a US study suggests.
Compared with women who did not have sleep problems, women with insomnia were 30 percent more likely to have a preemie and the odds of women with sleep apnea, a respiratory disorder, were 50 percent higher, according to the study.
“It’s normal to experience changes in sleep during pregnancy, often due to discomfort, pain or frequent trips to the bathroom,” said study author Jennifer Felder of the University of California at San Francisco.
“The current study focused on more disturbing sleep problems that were serious enough to result in a diagnosis of sleep disorder,” Felder said by e-mail.
Apnea, a potentially serious sleep disorder that involves repeated stops and starts in breathing, has been linked to high blood pressure during pregnancy, which is an independent risk factor for preterm birth. Obesity and advanced age can make apnea more likely.
Although many pregnant women have insomnia at some point, previous studies have not provided a clear picture of how this type of sleep deprivation influences the odds of preterm birth.
Worldwide, preterm birth is the leading cause of death for children under 5, the researchers report in the journal Obstetrics and Gynecology.
Pregnancy usually lasts about 40 weeks, and babies born after 37 weeks are considered at term. The new study focused on premature babies, delivered at 34 to 36 weeks of gestation, and extremely premature babies delivered before 34 weeks.
In the weeks immediately following birth, preemies often have difficulty breathing and digesting food. They may also face longer-term challenges such as vision, hearing, and cognitive skills, as well as social and behavioral problems.
The study team examined data from more than 3 million births in California from 2007 to 2012. They focused on 2,172 women who had a diagnosis of sleep disorder and compared their birth outcomes with a randomly selected group of 2,172 mothers who were similar In many ways, No sleep problems.
Women with sleep disorders were more likely to be black, age 35 or older, obese, and have other medical problems such as hypertension, diabetes, and infections, as well as increased odds of smoking or using drugs and alcohol during pregnancy. They were also more likely to have a history of preterm birth.
Overall, almost 15 percent of women with sleep disorders had a preterm birth, compared with 11 percent of women with no sleep problems.
The study was not a controlled experiment designed to demonstrate how even if sleep disorders directly cause premature births.
Even so, the results provide new evidence of the link between sleep disorders and early arrivals, said Dr. Ghada Bourjeily, a researcher at Warren Alpert Medical School at Brown University in Providence, Rhode Island, who was not involved in the study.
“Sleep seems to get worse in pregnancy in many, even women who do not have a pre-existing sleep disorder,” Bourjeily said. “Unfortunately, we still do not know whether improving sleep quality before or during pregnancy would prevent the development of negative outcomes such as preterm delivery.”
Beginning pregnancy at a healthy weight, however, can make sleep disorders less likely, said Dr. Amos Grunebaum, director of obstetrics at the New York-Presbyterian Hospital / Weill Cornell Medical Center in New York.
“Being overweight or obese increases the risk of having a sleep disorder,” said Grunebaum, who was not involved in the study by e-mail. “It also increases the complications of pregnancy.”
When sleep disorders appear during pregnancy, women should discuss the symptoms in detail with their doctors, said Dr. Milena Pavlova, a researcher at Boston’s Brigham and Women’s Hospital who was not involved in the study. This includes any problems with breathing, gasping or choking at night or any uncomfortable leg or body sensations that prevent sleep.
Pregnant mothers should also make sleep a priority in their schedules, said Pavlova, who did not participate in the study, by mail
