Relationship Between Body Mass Index and the Incidence of Perineal Tears in Primigravid Women: A Retrospective Cross-Sectional Study at a Hospital in Mexico.

INTRODUCTION

Perineal tears represent one of the main complications of vaginal delivery, with immediate and long-term consequences for maternal health. Although several factors have been associated with their occurrence, the role of maternal body mass index (BMI) remains controversial.

OBJECTIVE

This study aims to evaluate whether there is a significant difference in the incidence of perineal tears among primigravid women with different BMI categories.

METHODS

A retrospective cross-sectional study was conducted between March 2022 and February 2024 at the General Hospital of Specialties "Dr. Javier Buenfil Osorio" (Campeche, Mexico). A total of 180 (100%) primigravid women with term pregnancies were included and categorized according to BMI as normal weight, overweight, or obese. The incidence of perineal tears was compared among the groups.

RESULTS

The overall prevalence of perineal tears was 56.7% (102 patients). Tear rates were similar across BMI categories: normal weight with 58.3% (35 patients), overweight with 51.7% (31 patients), and obese with 60.0% (36 patients). No statistically significant differences were found (p = 0.622). Additionally, no correlation was identified using Kendall's Tau-b test (p = 0.854).

CONCLUSION

No significant association was observed between maternal BMI and the incidence of perineal tears in primigravid women. Other obstetric factors may play a more relevant role.