Maternal super obesity is increasing and is associated with an increased risk of pregnancy complications-a call for...

This study aimed to assess the relationship of increased body mass index (BMI) with pregnancy complications.

We obtained data for a retrospective cohort of singleton live births using an electronic birth certificate database from 2010 to 2022. Institutional review board exemption was obtained. BMI was assessed as a continuous variable and a categorical variable with groups of BMI 18.5-29.9 kg/m², 40-49.9 kg/m², and ≥50 kg/m² compared to patients with BMI 30-39.9 kg/m². Primary outcomes were pregnancy and maternal outcomes. Secondary outcomes were neonatal outcomes. ANOVA and χ² were used to compare continuous and categorical variables respectively, and logistic regression was used to obtain adjusted odds ratios for primary and secondary outcomes.

There were 223,837 patients with singleton live births with mean BMI 27.86 kg/m2. 54,385 (24.3%) had BMI 30-39.9 kg/m2, 13,299 (5.9%) had BMI 40-49.9 kg/m2, and 1,958 (0.87%) had BMI ≥50 kg/m2. Patients with BMI > 50 kg/m2 have a higher likelihood of APGAR scores <7 (aOR 1.38, 95% CI 1.05-1.83), and NICU admission or transfer out of facility (aOR 1.17, 95% CI 1.02-1.34). In the nulliparous subgroup analysis, For patients with BMI >50 kg/m2, there was a higher odds of preterm birth <37 weeks (aOR 1.57, 95% CI 1.23-2.00) and preterm birth <34 weeks (aOR 1.51 95% CI 1.00-2.30. There is also an increased odds of cesarean section in both of these BMI groups (aOR 1.68 95% CI 1.57-1.79 and aOR 2.30 95% CI 1.94-2.72).

BMI ≥ 50 kg/m² was significantly associated with increased pregnancy complications.