299 Factors associated with exclusive formula feeding among neonates of low risk pregnancies

Abstract

To assess factors associated with exclusive formula feeding in neonates of low risk pregnancies. A population-based, retrospective cohort study using the U.S. vital statistics datasets (2014–2018) evaluating low-risk pregnancies with a non-anomalous singleton delivery from 37 to 41 weeks of gestation. Patients with hypertensive disorders, diabetes, or missing information on neonatal feeding were excluded. The outcome was the type of neonatal feeding (non-exclusive formula feeding vs exclusive formula feeding) during hospital stay. Maternal and neonatal characteristics were compared between the two feeding groups. Potential factor variables were selected if bivariate analyses had a significant p-value <0.05 and standardized difference>0.10. Adjusted relative risks (aRRs) for formula feeding with 95% confidence intervals (CIs) were calculated. Of the 19,623,195 deliveries during the study period, 12,898,827 (65.7%) met inclusion criteria and among them, 2,226,813 (17.3%) had exclusive formula feeding. After multivariable regression adjustment, the factors associated with an increased risk of exclusive formula feeding included: maternal age <20 years (aRR: 1.19, 95% CI: 1.18-1.19), non-Hispanic black (1.26, 1.25–1.26), married status (1.59, 1.58–1.59), high school education (1.58, 1.58–1.59) or less than high school education (1.82, 1.81–1.82), Medicaid insurance (1.33, 1.33–1.33), pre-pregnancy body mass index (BMI) <18.5 (1.08, 1.07–1.08), BMI 25-29.9 (1.08, 1.08–1.00), BMI 30-34.9 (1.18, 1.17–1.18), BMI 35-39.9 (1.28, 1.28–1.29), BMI ≥40 (1.40, 1.39–1.41), multiparity (1.34, 1.34–1.35), lack of prenatal care (1.45, 1.44–1.46), smoking during pregnancy (1.59, 1.59–1.60), and small for gestational age (1.10, 1.10–1.11). Using a large population-based cohort of low risk pregnancies, we identified several modifiable factors associated with neonatal feeding (i.e. pre-pregnancy BMI, access to prenatal care, and smoking cessation). These factors should be addressed in order to achieve equitable care for all neonates.