Obesity and postpartum hospital use among individuals without additional medical comorbidities

The objective of this study was to examine whether obesity without preexisting or gestational comorbidities is associated with postpartum hospital use (PHU).

We studied 2016 to 2018 birth certificate and discharge data on 178,729 New York City births without International Classification of Diseases, Tenth Revision (ICD-10) codes at delivery for diabetes; hypertension; placental disease; anemia; thyrotoxicosis; bariatric surgery; and pulmonary, cardiac, renal, bleeding, autoimmune, digestive, neuromuscular, mental, or substance-use disorders. We defined PHU as ≥1 readmission or emergency department visit within 30 days of delivery discharge. We used ICD-10 codes to specify postpartum hypertension, infection, or hemorrhage during PHU (i.e., "cause-specific PHU") because these are leading mortality causes. We examined associations between prepregnancy BMI and PHU using multivariable logistic regression.

PHU incidence was 3.7% for those with normal weight, 5.1% for those with overweight, 6.3% for those with class 1 or 2 obesity, and 9.1% for those with class 3 obesity. A positive association persisted after adjustment. Obesity was associated with cause-specific PHU of postpartum hypertension (adjusted odds ratio [aOR]: 2.2, 95% confidence limits [CL]: 1.8-2.7, normal weight referent) and wound infection (aOR: 1.5, 95% CL: 1.2-1.8), but not hemorrhage (aOR: 0.9, 95% CL: 0.7-1.3), mastitis, or genitourinary infection (aOR: 1.1, 95% CL: 0.9-1.3).

Among individuals without other comorbidities, elevated BMI was associated with PHU. Findings can inform obstetric management to reduce morbidity during the critical fourth trimester.