Insomnia disorder at 6 weeks postpartum: a prospective study

To estimate the prevalence of insomnia disorder and insomnia symptoms, explore risk factors for insomnia disorder, and characterize sleep at 6 weeks postpartum.

Following IRB approval, adults who delivered a live infant at two academic US hospitals were prospectively recruited with a pre-specified cross-sectional analysis planned at 6 weeks postpartum, evaluating new sleep disturbance (SD) and sleep-related impairment (SRI) surveys. Participants were invited to complete surveys (Bergen Insomnia Scale (BIS), PROMIS SD, and SRI), and a structured clinical interview for sleep disorders (SCISD-R, the diagnostic standard), at 6 weeks postpartum, until 150 interviews were completed. Demographic and clinical variables were collected. Primary outcome was prevalence of insomnia disorder by SCISD-R; secondary outcomes were sleep characteristics and survey scores, clinical and sociodemographic factors associated with insomnia disorder, and exploratory evaluation of the diagnostic accuracy of BIS, PROMIS SD, and SRI for insomnia disorder identified by SCISD-R. Associations were assessed using univariate odds ratios and 95% confidence intervals, and receiver operating characteristic (ROC) curve was used to evaluate diagnostic accuracy of the surveys.

Of the 188 patients who accepted interview invitations, 150 completed interviews (79.8%) at 44 ± 7 days postpartum, mean age 33 ± 5 years. Insomnia symptoms were reported in 38 (25.3%) patients and 20 (13%) met diagnostic criteria for insomnia disorder. Only 2 had received clinical evaluation. Among 144 respondents, median BIS, PROMIS SD, and SRI T scores were 20 [IQR 14-27], 51 [IQR 45-56], and 57 [IQR 50-62] respectively, indicating normal SD and mild SRI in most patients. Fifty-one percent reported low or very low sleep satisfaction. Seventy percent reported sleeping ≤ 6 h. No statistically significant factors associated with insomnia disorder were identified, likely reflecting insufficient power rather than a true null finding. ROC curve analysis of BIS, PROMIS SD, and SRI in identifying insomnia disorder yielded area under the curve values of 0.73, 0.85, and 0.70 respectively.

The prevalence of insomnia disorder at 6 weeks postpartum was 13%, with most cases clinically undiagnosed. Improved screening strategies are needed.

Insomnia disorder is the most common sleep disorder in the postpartum period and accounts for up to 68% of sleep disorders; however, prevalence estimates of insomnia disorder in the first year after delivery vary widely. We aimed to estimate the prevalence of insomnia disorder and insomnia symptoms, explore risk factors associated with insomnia disorder, and characterize sleep at 6 weeks postpartum.

The prevalence of insomnia disorder at 6 weeks postpartum was 13%, with most cases clinically undiagnosed, demonstrating that improved screening strategies are needed. Beyond diagnosed insomnia disorder, a larger population of patients endorsed clinically meaningful sleep disturbance and sleep-related impairment without meeting diagnostic criteria for sleep disorder, revealing a gap in current sleep medicine frameworks that may leave affected patients overlooked in clinical care.