Emergency Care Use During Pregnancy and Severe Maternal Morbidity.

Importance: Pregnant individuals who repeatedly use emergency care during pregnancy represent a population who could be disproportionately vulnerable to harm, including severe maternal morbidity (SMM). Objective: To explore patterns of unscheduled care visits during pregnancy and ascertain its association with SMM at the time of birth. Design, Setting, and Participants: This cohort study used data from a statewide database that linked hospital records to births and fetal deaths occurring between October 1, 2002, and March 31, 2020, in Massachusetts. Pregnant individuals experiencing births or fetal deaths during the study period were included. Data analysis was conducted from June 2022 to September 2024. Exposure: The exposure was 4 or more cases of emergency use, defined as either an emergency department visit or observational stay during pregnancy not resulting in hospital admission. Pregnancy episode was ascertained by subtracting the gestational age at birth from the date of birth. Main Outcomes and Measures: The outcome of interest was the odds ratio (OR) for SMM at the time of birth. The algorithm includes 20 conditions or procedures (excluding transfusion) identified through International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes across the study period. Results: A total of 774 092 pregnant individuals (mean [SD] age, 31.2 [5.8] years; 16.8% Hispanic, 9.3% non-Hispanic Asian or Pacific Islander, 9.5% non-Hispanic Black, 63.1% non-Hispanic White) with emergency care visits during the pregnancy were included; 31.3% of these individuals had at least 1 visit. Overall, 18.1% had 1 visit and 3.3% had 4 or more visits. Four or more unscheduled visits were common among those younger than age 25 years (8.7%), with Hispanic (5.7%) or non-Hispanic Black (4.9%) race and ethnicity, with public insurance (6.5%), or with a comorbidity (19.0%) or an opioid use-related hospitalization (26.8%) in the year prior to pregnancy. Of those with 4 or more unscheduled visits, 43.8% visited more than 1 hospital during pregnancy. In a multivariable analysis of the likelihood of SMM, those with 4 or more unscheduled visits had an adjusted OR of 1.46 (95% CI, 1.29-1.66) compared with those with 0 visits. Conclusions and Relevance: This cohort study found that high emergency care use during pregnancy was associated with an increased risk for SMM. With a significant proportion of those with frequent unscheduled visits also using multiple hospitals, solutions that are community-based and integrated across health systems may be most beneficial.