Solids and formula: association with pattern and duration of breastfeeding.

OBJECTIVES To study changes in pattern and duration of breastfeeding associated with the introduction of solids and formula. STUDY DESIGN Descriptive longitudinal, prospective study. SETTING The participants were recruited from the maternity ward in the University Hospital in Uppsala, Sweden, between May 1989 and December 1992. A total of 15 189 infants were born during the period, 1 177 mother-infant pairs were found eligible for participation; 57% declined because of the perceived high workload. Study Population. Five hundred six mother-infant pairs. METHODS Daily recordings by the mothers on infant feeding, from the first week after delivery to the second menstruation postpartum or a new pregnancy; fortnightly home visits with structured interviews by a research assistant. RESULTS Introduction of solids was associated with no or minor changes in breastfeeding frequency and suckling duration. Breastfeeding frequency remained constant the first month after the introduction and then declined slowly, while daily suckling duration started to decline slowly when solids were introduced. Breastfeeding duration was not associated with infants' age at introduction of solids. In infants given formula, as soon as regular formula feeds started, the breastfeeding frequency and suckling duration declined swiftly. The younger an infant was at the start of regular formula feeds, the shorter the breastfeeding duration. CONCLUSIONS Health care personnel and parents need to be aware that introduction of solids and introduction of formula can have very different consequences for breastfeeding. If the aim is to introduce other foods to breastfed infants under the protection of breast milk, it is important to realize that formula is also another food and needs to be treated as such.