(937) The rate of maternal comorbidities among different body mass index groups

The purpose of this study was to describe the association between body mass index (BMI) at delivery and the rates of different maternal comorbidities among obese pregnant individuals.

Study Design:

This is a retrospective cohort study of all singletons ≥14 weeks that were delivered between March 2020 and February 2022 at a single Level IV center. We categorized the cohort by different BMI classes: overweight (25–29.9 kg/m²), class I/II (30-39.9 kg/m²), class III (40-49.9 kg/m²), and class IV ≥ 50 kg/m². The reference group was the overweight cohort. The rates of composite comorbidities (hypertensive disorder of pregnancy, diabetes, asthma, cardiac disease, mental illness, or venous thromboembolism (VTE)) were ascertained. Poisson regression was used to calculate adjusted relative risks for each comorbidity by class, adjusted for age given that age is most likely to influence rate of comorbidities.

Results:

Of 8,623 deliveries, 7618 (88.3%) met inclusion criteria. 29.2% were overweight (n=2221), 51.2% were class I/II (n =3900),16% were class III (n=1220), and 3.6% were class IV (n=277). Compared to overweight, class I/II, III and IV were significantly more likely to have composite co-morbidities (aRR 1.37 (1.29-1.46), aRR 1.82 (1.70-1.95), and 2.18 (2.01-2.35), respectively.) After adjusting for maternal age, class IV obesity demonstrated statistically significant higher risk of hypertensive disorders (aRR 3.09, 95% CI 2.77 -3.45), diabetes (aRR 3.99, 95% CI 3.16-5.03), asthma (aRR 2.03, 95% CI 1.44-2.88), and mental illness (aRR 1.58, 95% CI 1.11-2.25) (Table 1.)

Conclusion:

As BMI increases, the rate of several maternal comorbidities increases, with composite morbidity reaching 66% in class III individuals and 90% in Class IV individuals. Obese patients are an increasing constituent in contemporary obstetric populations and BMI alone does not accurately reflect the medical complexity and subsequent challenges in care. Given the increased risk of maternal comorbidities in Class IV obesity, frequent maternal surveillance should be considered for early detection and management of comorbidities.