To test the hypothesis that sleep disorder diagnosis would be associated with increased risk of preterm birth and to examine risk by gestational age, preterm birth type, and specific sleep disorder (insomnia, sleep apnea, movement disorder, and other).
In this observational study, participants were from a cohort of nearly 3 million women in California between 2007 and 2012. Inclusion criteria were women with singleton neonates liveborn between 20 and 44 weeks of gestation without chromosomal abnormalities or major structural birth defects linked to a hospital discharge database maintained by the California Office of Statewide Health Planning and Development and without mental illness during pregnancy. Sleep disorder was defined based on International Classification of Diseases, 9th Revision, Clinical Modification diagnostic code (n=2,265). Propensity score matching was used to select a referent population at a one-to-one ratio. Odds of preterm birth were examined by gestational age (less than 34 weeks, 34–36 weeks, and less than 37 weeks of gestation) and type (spontaneous, indicated).
Prevalence of preterm birth (before 37 weeks of gestation) was 10.9% in the referent group compared with 14.6% among women with a recorded sleep disorder diagnosis. Compared with the referent group, odds (95% CI, P value, percentage) of preterm birth were 1.3 (1.0–1.7, P=.023, 14.1%) for insomnia and 1.5 (1.2–1.8, P<.001, 15.5%) for sleep apnea. Risk varied by gestational age and preterm birth type. Odds of preterm birth were not significantly increased for sleep-related movement disorders or other sleep disorders.
Insomnia and sleep apnea were associated with significantly increased risk of preterm birth. Considering the high prevalence of sleep disorders during pregnancy and availability of evidence-based nonpharmacologic interventions, current findings suggest that screening for severe presentations would be prudent.
Insomnia disorder and sleep apnea are associated with increased risk of preterm birth.
Department of Psychiatry, the California Preterm Birth Initiative, the Center for Health and Community, the Department of Obstetrics, Gynecology and Reproductive Sciences, and the Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California; and the Department of Pediatrics, University of California, San Diego, San Diego, California.
Corresponding author: Jennifer N. Felder, PhD, University of California, San Francisco, 3333 California Street, Suite 465, San Francisco, CA 94118; email: Jennifer.Felder@ucsf.edu.
Supported by The California Preterm Birth Initiative (PTBi-CA) at the University of California, San Francisco, funded by Marc and Lynne Benioff.
Financial Disclosure Dr. Prather is a paid consultant for Posit Science on an unrelated project. The other authors did not report any potential conflicts of interest.
Each author has indicated that he or she has met the journal's requirements for authorship.