Observations and Conversations: A Mixed Methods Approach to Describing Home-Preparation of Infant Formula among a Sample of Low-Income Mothers

Background: The obesity epidemic in the United States (US) is a well-established public health crisis associated with immense national healthcare expenditures. The first two years of life represent a potentially critical intervention period for attenuation of inappropriate rapid weight gain and risk of subsequent overweight and obesity in childhood. Low-income mothers in the US are at risk for formula-feeding and early introduction of solid foods, which are behaviors that could lead to excessive rapid weight gain during this critical time period. However, little is known about actual, rather than self-reported, maternal infant-feeding behaviors related to proper infant formula preparation.

Objective: To explore maternal infant formula preparation practices and related knowledge, attitudes, and beliefs, among low-income, formula-feeding mothers of very young infants.

Methods: This study utilized a cross-sectional, mixed methods design. Participants were mothers of normal birth weight, healthy, term infants less than three months of age, who were predominantly formula-feeding with powdered or from-concentrate infant formula, and who were WIC income-eligible. Study activities included home observations of infant formula preparation and in-depth interviews. Descriptive statistics were used to describe the sample demographic characteristics and home-observation variables. Thematic analysis was used to identify themes present in the in-depth interviews. The mixed methods approach was used to triangulate results of both study activities.

Results/Conclusions: Behaviors including over-concentration, over-dilution, modifications/additions to prepared infant formula, and early introduction of solid foods (i.e., cereal added to bottles of infant formula) were observed during the home observations and/or were described during the in-depth interviews. Additionally, there appeared to be inconsistencies between behaviors observed during formula preparation and those reported in subsequent in-depth interviews. Targeting knowledge and skills gaps along with motivators of maternal behaviors in this population could diminish the prevalence of infant-feeding practices that may predispose infants to inappropriate rapid weight gain.