The findings showed that the prevalence of preterm birth - defined as delivery before 37 weeks' gestation - was 14.6 percent for women diagnosed with a sleep disorder during pregnancy compared to 10.9 percent for women who were not.
The odds of early preterm birth - before 34 weeks - was more than double for women with sleep apnoea and nearly double for women with insomnia.
Treating sleep disorders during pregnancy could be a way to reduce the preterm rate which is about 10 percent in the US, more than most other highly developed countries, said lead author Jennifer Felder, post-doctoral student at the University of California - San Francisco.
For the study, published in the journal Obstetrics & Gynecology, the team analysed 2265 women with a sleep disorder diagnosis during pregnancy. They were then matched to those who did not have such a diagnosis but had identical maternal risk factors for preterm birth such as a previous preterm birth, smoking during pregnancy or hypertension.
"What's so exciting about this study is that a sleep disorder is a potentially modifiable risk factor," Felder said.
Globally, 15 million babies are born prematurely - more than three weeks before the typical full-term pregnancy of 40 weeks - each year.
Among these, 1.1 million die from birth-related complications while others are left with hearing impairment, learning disabilities, cerebral palsy and other health issues.