Association Between Prepregnancy Body Mass Index and Newborn Breastfeeding Initiation

Background: The benefits of breastfeeding a newborn are well documented. Identification of mothers who do not initiate breastfeeding is essential for developing initiatives to improve breastfeeding initiation. Methods: The study used data from the National Center for Health Statistics (NCHS) National Vital Statistics System (NVSS) birth certificate data (2014-2021) to identifying 15,599,930 in-hospital deliveries. We used multivariable logistic regression to assess the association between seven body mass index (BMI) categories and initiation of breastfeeding before hospital discharge. Prepregnancy BMI (weight in kilograms/height in meters²) included underweight (<18.5), healthy weight (18.5-24.9), overweight (25.0-29.9), Obesity Class I (30-34.9), Obesity Class II (35-39.9), and Obesity Class III (40-49.9) classes, in addition to a class newly identified in the literature as super obese (≥50), hereafter "Obesity Class IV." "This project was deemed non-human subjects research." Results: Approximately, 83% of mothers initiated breastfeeding before hospital discharge. Compared to mothers with a healthy prepregnancy BMI, the likelihood of breastfeeding initiation before hospital discharge decreased with increasing prepregnancy BMI. Specifically, we found reduced likelihood of initiation for mothers who were overweight (adjusted odds ratio [aOR]: 0.952, 95% confidence interval [CI]: [0.948-0.955]), Obesity Class I (aOR: 0.884, 95% CI: [0.880-0.888]), Obesity Class II (aOR: 0.816, 95% CI: [0.811-0.820]), Obesity Class III (aOR: 0.750, 95% CI: [0.745-0.755]), and Obesity Class IV (aOR 0.672: 95% CI: [0.662-0.683]). Conclusions: Mothers with prepregnancy BMI above the healthy range had reduced likelihood of initiating breastfeeding prior hospital discharge. This information should be used to develop and initiate interventions for mothers who wish to breastfeed but may need additional lactation assistance support.