The influence of body mass index on the risk of adverse pregnancy outcomes in preeclampsia

Objectives This study aimed to evaluate the influence of Body Mass Index (BMI) on adverse pregnancy outcomes in women with preeclampsia. Methods A retrospective observational study was conducted on patients with preeclampsia who delivered at Dr. Soetomo General Hospital from 2013 to 2023. Patients were categorized into four BMI groups: underweight (< 18.5 kg/m2), normal (18.5–22.9 kg/m2), overweight (23-27.5 kg/m2), and obese (> 27.5 kg/m2). Maternal and neonatal outcomes were analyzed using SPSS version 29. Results The study included 3,071 patients. Higher BMI was associated with increased maternal age, multiparity, and gestational age at preeclampsia diagnosis. Overweight and obese women showed a reduced risk of severe preeclampsia, HELLP syndrome, and preterm birth, but a higher risk of cesarean section. Specifically, the occurrence of eclampsia, severe preeclampsia, and HELLP syndrome was reduced in the obese group compared to the normal BMI group, while severe preeclampsia complications were more prevalent in the underweight group. The underweight group also exhibited the longest duration of hospitalization. For neonatal outcomes, newborn weight increased with rising maternal BMI, but the prevalence of fetal growth restriction, perinatal death, and NICU admission was highest in the underweight group. Conclusion Overweight and obesity may have a protective effect against adverse pregnancy outcomes in preeclamptic women, while underweight is associated with increased risks. These findings suggest that BMI is a critical factor in preeclampsia management.