Medical Sciences
Maternal Obesity and Outcomes During Pregnancy and the Puerperium: A Single-Center Retrospective Observational Study
By Denise de Souza Ribeiro, L Marques and Fernando Augusto Lima Marson.
Abstract
Background
Maternal obesity is associated with pregnancy complications and adverse perinatal outcomes, although observational associations may be influenced by confounding, exposure ascertainment, and missing data. This study investigated associations between recorded maternal body mass index (BMI) and maternal clinical conditions, obstetric complications, delivery characteristics, and perinatal outcomes in a referral center.
Methods
A retrospective study was conducted using medical records of pregnant women at a referral center. Recorded maternal BMI categories were classified according to the World Health Organization. Database standardization harmonized equivalent diagnostic terms, preserved maternal clinical conditions and obstetric complications as separate domains, and grouped uncommon conditions for descriptive and exploratory analyses. Missing non-BMI variables underwent multiple imputation across 50 completed datasets; maternal BMI was not imputed. Twin pregnancies were excluded, and women with and without recorded BMI were compared before and after imputation. All singleton pregnancies with recorded BMI were included descriptively, whereas association analyses excluded women with underweight because of their small number and absence of recorded primary-outcome events. The primary composite perinatal outcome comprised neonatal intensive care unit admission, recorded fetal death or stillbirth, or a 5-min Apgar score <7 among liveborn infants. Logistic regression models compared overweight and obesity with normal weight, adjusting for maternal age and parity. Selected outcomes underwent additional adjustment for smoking, chronic hypertension, and pre-existing diabetes mellitus. Complete-case analyses assessed the sensitivity of the core findings.