Preconception and perinatal hospitalizations as indicators of risk for severe maternal morbidity in primiparas

Abstract

Severe maternal morbidity (SMM) includesunexpected outcomes of labor and delivery that result in significant short- or long-term consequences to a woman's health. We used a statewide longitudinally linked database to examine hospitalization during and prior to pregnancy for birthing people with SMM at delivery. To examine the association between hospital visits during and 1-5 years prior to pregnancy and severe maternal morbidity at delivery. We performed a retrospective, population-based cohort analysis of the Massachusetts Pregnancy to Early Life Longitudinal database between January 1, 2004 and December 31, 2018. Non-birth hospital visits including emergency visits, observational stays, and hospital admissions during pregnancy, and five years prior to pregnancy, were identified. Diagnoses for hospitalizations were categorized. We compared medical conditions leading to antecedent, non-birth hospital visits among primiparous birthing individuals with singleton births with and without SMM, excluding transfusions. Among 235,398 deliveries over this period, we identified 2,120 complicated by SMM, a rate of 90.1/10,000, and 233,278 without SMM. A total of 10.4% of those with SMM were hospitalized during pregnancy compared to 4.3% without. In multivariable analysis, there was a 31% increased risk for hospital admission during the prenatal period, 60% in the year prior to pregnancy and 41% increased risk in the 2-5 years prior to pregnancy. One in seven (14.9%) non-Hispanic Black birthing people with SMM experienced a hospital admission during pregnancy compared to 9.8% among non-Hispanic Whites. For those with SMM, a prenatal hospitalization was most common for those with endocrine (3.6%) or hematologic (3.3%) conditions, with the largest differences between those with and without SMM for musculoskeletal (RR 9.82, 95% CI 7.06-13.64) and cardiovascular (RR 9.73 95% CI 7.26-13.03) conditions. We found a strong association between prior non-birth hospitalizations and the likelihood of SMM at delivery.