PURPOSE OF THE STUDY.
To determine if different infant feeding patterns in the first 6 months of life increase the risk of eczema and/or skin allergy in children in the first 6 years of life.
The sample population was originally derived from a national consumer opinion panel consisting of 500 000 households from throughout the United States from May 2005 to June 2007. Inclusion criteria included women ≥18 years of age in their third trimester of pregnancy, proficiency in English, a stable address for at least 11 months, a healthy mother and infant at birth, term or near-term birth (>35 weeks’ gestation), singleton birth, an infant weighing at least 5 lb and not in the ICU for >3 days. Exclusion criteria included serious long-term health problems that would affect feeding. Original questionnaires obtained in the Infant Feeding Practices Study II had a sample size of 2907 mother-infant dyads at birth and 1782 at month 12. In 2012, the mothers were recontacted about their child’s well-being at age 6 years. The final sample consisted of 1387 woman-child dyads who provided information on feeding practices in the first 6 months of life and participated in the 6-year follow-up survey.
Data were extracted from the Infant Feeding Practices Study II in the United States and its 6-year follow-up. Questionnaires were completed prenatally, near birth, at 1 month, every other month from 2 to 7 months, and then every 7 weeks until age 12 months. Data that were collected included age at onset of eczema, maternal race, family history of eczema, maternal age during pregnancy, parity, maternal prepregnancy BMI, maternal education, marital status, maternal employment, poverty index, household smoking status, sex of infant, birth weight, mode of delivery, and season of delivery. Six different feeding patterns were identified: (1) direct breastfeeding for 1 month; (2) direct breastfeeding for 3 months; (3) direct breastfeeding and pump feeding for the first 3 months; (4) direct breastfeeding, pump feeding, and formula feeding in the first few months; (5) formula feeding for the first 2 to 3 months followed by additional solid food; and (6) formula feeding and solid food since age 1 month. Log-linear models were used to estimate prevalence ratios (PRs) of feeding patterns for infants after doctors diagnosed eczema and/or skin allergy in the first 6 years of life, adjusting for cofounders. Current eczema and/or skin allergy at year 6 of follow-up was used to characterize the disease.
Children who received a combination of direct breast milk, pumped breast milk, and formula (pattern 4) had a statistically significant higher PR for eczema and/or skin allergy than children who were directly breastfed for the first 3 months of life (PR: 1.46; 95% confidence interval: 1.01–2.11) in the 6-year evaluation studies. Direct breastfeeding and pump feeding for the first 3 months (pattern 3) also revealed an increased PR; however, it was not statistically significant (PR: 1.26; 95% confidence interval: 0.85–1.89). Formula feeding introduced at birth had no higher risk for the development of eczema.
Children who are directly breastfed for the first 3 months of life may have a decreased risk of eczema and/or skin allergy compared with children who drink breast milk both from a bottle and from the breast and are supplemented with formula.
Breastfeeding is thought to provide better protection against allergic disease than formula feeding. However, there are several studies with inconclusive or conflicting results. In this study, the authors postulate that the inconsistencies are because the patterns of breastfeeding versus formula feeding are much more diversified. They suggest that pumped breast milk components may be altered in the freezing and reheating process, resulting in a loss of immunoglobulins and a reduction in lipase. The expression of milk may also introduce skin microorganisms into the milk. This large birth cohort study is 1 of few studies in which the trajectory of infant feeding with its relationship to the development of eczema and/or skin allergy in children is managed. These findings reveal the possible benefit of direct breastfeeding in the first 3 months of life in decreasing eczema and skin allergy. Although most pediatricians would argue that “breast is best,” how it is presented and whether it is with or without supplemental formula may affect the immune system in the gut and influence the development of eczema.