Postpartum readmission after unscheduled cesarean delivery in patients with class 3 obesity.

Objective: Identify risk factors for postpartum readmission in class 3 obese patients undergoing unscheduled cesarean deliveries.

Study design: Retrospective cohort study of patients with BMI ≥ 40 kg/m2 undergoing unscheduled cesarean delivery from 2017-2020 comparing patients with and without postpartum readmission (unexpected admission, emergency room/overnight observation visit, unscheduled outpatient visit, or ambulatory surgery within 30 days). Medical history, operative data, and postpartum outcomes were compared between the cohorts.

Results: "The electronic medical record was queried to identify cesarean deliveries documented as 'unscheduled'". 255 of 1273 identified patients (20.0%) had a postpartum readmission. Median BMI was similar between the cohorts (44.2 kg/m2, IQR [41.8, 47.9] vs. 44.8 kg/m2 [42.0, 48.9], p= 0.066). Readmitted patients were more likely to have a history of smoking during or prior to pregnancy (p= 0.046). A sub-group exploratory analysis excluding outpatient and emergency room visits demonstrated higher rates of type II diabetes mellitus in patient's with postpartum readmission (11.5% vs 4.6%, p= 0.030). Patients with readmission in comparison to those without readmissions were less likely to receive cefazolin prophylaxis (78.0% vs 84.3%, p= 0.014) in comparison to gentamicin/clindamycin prophylaxis. Patients with readmission were less likely to have had vaginal preparation (56.9% vs 64.3%, p= 0.027). On multivariable logistic regression analysis, smoking history (OR 1.44, 95% CI 1.06-1.96, p= 0.0220) and hypertensive disease (OR 1.57, 95% CI 1.18-2.09, p 0.002) were associated with readmission. Cefazolin preoperative prophylaxis (OR 0.59, 95% CI 0.41-0.84, p= 0.004) and vaginal sterile preparation (OR 0.72, 95% CI 0.54- 0.95, p= 0.022) were associated with decreased risk of readmission.

Conclusions: In class 3 obese patients, a history of smoking and a diagnosis of hypertensive disease associate with increased risk of postpartum readmission. Perioperative antibiotic prophylaxis with cefazolin along with vaginal sterile preparation associate with decreased risk of postpartum readmission.