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Faculty have requested this content not be shared on social media
CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
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Poster Session 2

(470) Comparison of Weight Gain versus BMI During Pregnancy on Perinatal Outcomes in Singleton Term Pregnancies

Thursday, January 30, 2025
4:00 PM – 6:00 PM  
Objective:
Excessive gestational weight gain (GWG) and obesity have significant adverse perinatal risks. Our study compares the impact of excessive GWG on maternal and neonatal outcomes in pregnancies with normal pre-pregnancy BMI (18.5 – 24.9) to those who had pre-pregnancy BMI ≥ 25 with recommended weight gain.


Study Design:
We performed a retrospective cohort study using the National Vital Statistics Database and included singleton, non-anomalous live births who delivered at term from 2016-2022. We excluded patients with multifetal gestations, chronic hypertension and pre-gestational diabetes. We compared three groups: Group 1 (normal pre-pregnancy BMI with excessive GWG), Group 2 (overweight pre-pregnancy BMI (25.0 – 29.9) with recommended GWG) and Group 3 (obese pre-pregnancy BMI (≥ 30) with recommended GWG). Recommended GWG was defined according to AIUM standards across BMI strata. Multivariate Poisson regression models with robust error variance were used to examine the association. Adjusted relative risk (aRR) with 95% confidence intervals were calculated.


Results:
Our study included 6,352,304 patients. Compared to Group 1, overweight and obese patients had a higher risk of composite adverse maternal outcome, mostly due to increased risk of gestational diabetes and cesarean birth. Those with recommended GWG despite being overweight or obese were less likely to have hypertensive disorders (Group 2 aRR 0.92, 95% CI 0.91-0.92) and operative vaginal birth (Group 2 aRR 0.93, 95% CI 0.92-0.94; Group 3 aRR 0.73, 95% CI 0.72-0.74). Compared to Group 1, Group 2 had a reduced risk of the composite neonatal adverse outcome (aRR 0.74, 95% CI 0.74-0.74), mostly due to a reduced risk of large for gestational age fetuses (aRR 0.64, 95% CI 0.64-0.64) and NICU admission (aRR 0.98, 95% CI 0.98-0.99).


Conclusion: While pre-pregnancy BMI is a crucial predictor of these outcomes, recommended weight gain during pregnancy mitigates these risks by improving maternal and neonatal outcomes. Additional studies are needed to quantify the risk of excessive GWG in those with other high-risk conditions.