DENVER (FRONTLINE MEDICAL NEWS) – Women who experience difficulty staying asleep are at increased risk of having one or more pregnancies that don’t result in a live birth, a large epidemiologic study suggests.

In contrast, other expressions of insomnia – difficulty in falling asleep, early morning awakening, or nonrestorative sleep – were not significantly associated with pregnancy loss in this analysis of a nationally representative sample comprised of 5,554 women aged 18-45 years, Sara Nowakowski, Ph.D., reported at the annual meeting of the Associated Professional Sleep Societies.

The women were participants in the National Health and Nutrition Examination Survey for 2005-2008, which collected data on reproductive history as well as sleep patterns. Roughly 20% of the women self-reported experiencing insomnia. Eighty-three percent of the 18- to 45-year-old women had been pregnant at least once, and 1,870 (40%) of them had one or more prior pregnancies that didn’t result in a live birth.

In a multivariate logistic regression analysis adjusted for age, race, education level, and frequency of sleep apnea symptoms, such as snoring or snorting/gasping, frequent difficulty in maintaining sleep was independently associated with an 85% increased risk of having experienced a pregnancy that didn’t result in a live birth, according to Dr. Nowakowski , a clinical psychologist in the department of ob.gyn. at the University of Texas, Galveston.

In an interview, she was quick to note that these are correlational, hypothesis-generating data, and that an epidemiologic study such as this can’t establish causality.

Dr. Nowakowski and her coinvestigators hope to conduct a prospective randomized trial of cognitive behavioral therapy for insomnia – a well-established treatment – in a group of women with prior spontaneous abortion, miscarriage, or other infertility issues, to determine whether insomnia is a modifiable risk factor for adverse pregnancy outcomes.

One physician at the meeting remarked that if women with fertility problems and insomnia knew of Dr. Nowakowski’s work showing an association between insomnia and unsuccessful pregnancies, they would be pounding down the doors of sleep specialists. Dr. Nowakowski agreed.

“I surf the online networks set up for infertile women. They’re very distraught over their trouble conceiving. They’re doing yoga, de-stress programs, taking all sorts of supplements – including melatonin – to try to improve their chances of fertility,” she said. “If insomnia turns out to partially account for the risk of having pregnancies that don’t result in live birth, and treating the insomnia reduces that risk, there would be a huge amount of patient interest.”

The study was supported by the National Institutes of Health. Dr. Nowakowski reported having no financial conflicts.