Unplanned pregnancy and severe maternal morbidity

OBJECTIVE: To measure the association between unplanned pregnancy and severe maternal morbidity (SMM). DESIGN: Retrospective cohort study. SUBJECTS: Prepandemic singleton deliveries from January 1, 2019 to December 31, 2019 at two Philadelphia hospitals. EXPOSURE: Unplanned pregnancy, self-reported at the start of pregnancy. MAIN OUTCOME MEASURES: Severe maternal morbidity with blood transfusion, identified using Centers for Disease Control and Prevention (CDC) methodology. Covariates included maternal age, race, ethnicity, insurance, site of care, chronic hypertension, diabetes, and prepregnancy body mass index. We compared unadjusted and adjusted associations between unplanned pregnancy and SMM using complete case analysis, inverse probability weighting, and multiple imputation. RESULTS: The cohort consisted of 9,592 births, unplanned pregnancy was assessed in 32.8% (n=3,153) patients. Across all methods to address missing data, unplanned pregnancy was not associated with SMM (complete case adjusted odds ratio [aOR] 0.80, 95% confidence interval 0.60-1.09), either before or after adjustment for covariates. CONCLUSION: In this cohort, unplanned pregnancy was not associated with SMM. More nuanced measures of pregnancy planning behavior, especially among people at high risk of SMM, warrants future investigation.