(979) Severe maternal morbidity and adverse pregnancy outcomes in patients with isolated obesity

Pregnancy outcomes of people with obesity but without other significant pre-pregnancy comorbidity are not well characterized. The objective of this study was to determine rates of severe maternal morbidity (SMM) and adverse pregnancy outcomes in patients with isolated obesity.

Study Design: This study was conducted using the TriNetX Diamond Network, a research network comprising data from 92 health care organizations, from inception in 2009-8/2023. Patients 12-55 years with isolated obesity (body mass index (BMI) greater than or equal to 30 kg/m2 and without other comorbidity) at least one year before delivery encounter were compared to non-obese patients (BMI less than 30 kg/m2). Patients were excluded from both cohorts for any history of hypertension, diabetes mellitus, hyperlipidemia, bariatric surgery, heart disease, prior cesarean section (C/S), multiple gestation, or systemic lupus erythematosus. The primary outcome was composite severe maternal morbidity (SMM), defined using Centers for Disease Control ICD-10 codes. Individual indicators of SMM and adverse pregnancy outcomes (C/S, postpartum hemorrhage, spontaneous preterm birth, preeclampsia) were secondary outcomes. The TriNetX platform was used to perform 1:1 propensity score matching (age, race, ethnicity) and logistic regression. Comorbid conditions were not used to match, as patients with significant comorbidity had been already excluded from the cohort.

Results: After propensity score matching, 46,862 individuals of similar age, race, and ethnicity were included in each cohort. Compared to a healthy, non-obese cohort, pregnant patients with isolated obesity had significantly increased odds of composite SMM. Obese patients also had significantly increased odds of renal failure, blood transfusion, preeclampsia, eclampsia, cerebrovascular disorders (e.g., stroke), sepsis, embolism, C/S, postpartum hemorrhage, and spontaneous preterm birth (Figure). 

Conclusion:

Pregnant patients with isolated obesity are more likely to experience SMM and adverse pregnancy outcomes compared to non-obese, healthy patients.