Results
The source database comprised 1012 records. After excluding 13 twin pregnancies, 999 singleton pregnancies remained; BMI was recorded for 787 women and missing for 212 (21.2%). Among women with recorded BMI, 27 (3.4%) had underweight, 282 (35.8%) normal weight, 210 (26.7%) overweight, and 268 (34.1%) obesity. Association analyses included 760 women. Compared with normal weight, obesity was associated with maternal clinical conditions (adjusted odds ratio, 3.04; 95% confidence interval, 2.06–4.49), chronic hypertension (8.96; 4.14–19.38), obstetric complications (4.12; 2.83–5.99), hypertensive disorders of pregnancy (6.12; 3.60–10.40), gestational diabetes mellitus (2.43; 1.48–3.97), cesarean delivery (3.18; 2.12–4.75), and large-for-gestational-age birth (5.99; 2.74–13.13). Overweight was also associated with obstetric complications, gestational diabetes mellitus, cesarean delivery, and large-for-gestational-age birth. The associations between obesity and overall obstetric complications, hypertensive disorders of pregnancy, and large-for-gestational-age birth remained evident in expanded models. No statistically significant association was observed with the primary composite outcome for overweight (0.58; 0.21–1.57) or obesity (1.16; 0.54–2.53), and complete-case analyses were similarly inconclusive. Core models did not identify statistically significant associations with preterm birth, small-for-gestational-age birth, or low birth weight. The exploratory association with perineal tears was attenuated after adjustment. Women without recorded BMI had fewer recorded maternal clinical conditions, obstetric complications, and cesarean deliveries, but more composite perinatal events; these differences persisted after imputation.
