Transitions in Health Insurance During the Perinatal Period Among Patients With Continuous Insurance Coverage.

Importance: Although health insurance continuity is important during the perinatal period to improve birth outcomes and reduce maternal morbidity and mortality, insurance disruptions are common. However, little is known about insurance transitions among insurance types for individuals who remained insured during the perinatal period. Objective: To examine insurance transitions for birthing individuals with continuous insurance, including those with Medicaid and Medicaid managed care coverage, before, during, and after pregnancy. Design, Setting, and Participants: This cohort study used January 1, 2014 to December 31, 2018 data from the Massachusetts All-Payer Claims Database. The sample included deliveries from January 1, 2015, to December 31, 2017, to birthing individuals aged 18 to 44 years old with continuous insurance for 12 months before and after delivery. Data were analyzed from November 9, 2021, to September 2, 2022. Exposure: Insurance type at delivery. Main Outcomes and Measures: The primary outcome was a binary indicator of any transition in insurance type from 12 months before and/or after delivery. The secondary outcomes were measures of any predelivery transition (12 months before delivery month) and any transition during the postpartum period (delivery month to 12 months post partum). Multivariate logit regression models were used to analyze the association of an insurance transition in the perinatal period with insurance type in the delivery month, controlling for age and socioeconomic status based on a 5-digit zip code. Results: The analytic sample included 97 335 deliveries (mean [SD] maternal age at delivery, 30.4 [5.5] years). Of these deliveries, 23.4% (22 794) were insured by Medicaid and 28.1% (27 347) by Medicaid managed care in the delivery month. A total of 37.1% of the sample (36 127) had at least 1 insurance transition during the 12 months before and/or after delivery. In regression-adjusted analyses, those individuals covered by Medicaid and Medicaid managed care at delivery were 47.0 (95% CI, 46.3-47.7) percentage points and 50.1 (95% CI, 49.4-50.8) percentage points, respectively, more likely to have an insurance transition than those covered by private insurance. Those covered by Marketplace plans at delivery had a 33.1% (95% CI, 31.4%-34.8%) regression-adjusted predicted probability of having a postpartum insurance transition. Conclusions and Relevance: Results of this study showed that insurance transitions during the perinatal period occurred for more than 1 in 3 birthing individuals with continuous insurance and were more common among those with Medicaid or Medicaid managed care at delivery. Further research is needed to examine the role of insurance transitions in health care use and outcomes during the perinatal period.