Maternal Prepregnancy Body Mass Index and Initiation and Duration of Breastfeeding: A Review of the Literature

Background: Previous studies have found an association between maternal obesity and overweight and breast-feeding (BF) difficulties, including delayed lactogenesis and shorter duration of BF. Biological, psychological, and mechanical causes have been linked with poor BF outcomes. Other review articles on this topic have included studies that measured maternal body mass index (BMI) in the postpartum period instead of prenatally, presenting difficulties in teasing out the role of gestational weight gain and prepregnancy BMI on BF success. My objective was to evaluate the relationship between maternal prepregnancy BMI, including comorbidites associated with overweight and obesity such as diabetes mellitus, and BF initiation and duration. Methods: Four PubMed searches were conducted, retrieving 13 articles. Results: Of the 12 studies reviewed that assessed the association between prepregnancy maternal BMI category and BF initiation, 9 found an association between maternal overweight or obesity and delayed lactogenesis or failure to initiate BF. One study found increased risk for not initiating BF only in Hispanic women, and 1 found the association only among women with medical comorbidities in addition to obesity. Of the 13 studies retrieved that assessed the association between BMI category and BF duration, 10 found an association between higher BMI categories and shorter duration of BF. Ten of the 13 studies reviewed adjusted for multiple confounders, including maternal smoking status, parity, type of delivery, and infant birthweight. The studies that found an association between BMI category and reduced duration did so in some cases only for certain ethnic/racial groups or BMI categories or if other comorbidities were present in addition to overweight/obesity. Conclusions: Higher BMI levels can adversely impact BF initiation and duration. Further studies need to be conducted to better understand the role of race/ethnicity, gestational weight gain, and such comorbidities as diabetes in increasing risk for reduced BF initiation and duration in overweight and obese women.