OP-003 Labour induction in obese patients

The practice of induced labour has risen to approximately 33% of all pregnancies. It is essential to know what the outcome will be for patients with higher BMI, as it is a high-risk pregnancy, and this would help avoid surgical interventions and related complications in the future. This study aimed to see how a woman's BMI affects the outcome of induced labour.

This retrospective study used data from Riga Maternity Hospital and included 8759 women presenting with induced labour from 2016 to 2022. The data was processed using IBM SPSS Statistics version 28, comparing induction outcomes in two main groups: first-primiparas and second-multiparas. Next, these two groups were divided by BMI and studied separately — Group A or control group with BMI<25; Group B – BMI 25-29; Group C – BMI 30-39; Group D – BMI > 39.

Primiparas with normal BMI in 23% had a CS, and in 77% had a vaginal birth. Group B primiparas in 31% had a CS, so OR to have a CS is 1.5 (95% CI 1.3-1.8). Group C primiparas in 41% had a CS, so OR is 2.3 (95% CI 1.8-2.8). Group D primiparas in 43% had a CS, so OR to have a CS is 2.6 (95% CI 1.5-4.6). Multiparas with a normal BMI in 7% had a CS, and 93% had a vaginal birth. Group B multiparas in 11% had a CS, so OR is 1.8 (95% Ci 1.4-2.4) Group C multiparas had CS in 13%, so OR is 2.1 (95% CI 1,5-3). Almost all group D multiparas had vaginal birth (95% CI 0.3-2.7).

Primiparas with obesity have a high CS rate. CS risk increases with the primipara BMI. Multiparas with obesity, despite the BMI, have a high chance of delivering vaginally. Having a normal BMI to deliver the first baby is highly recommended.