Studies on perceived breast milk insufficiency. A prospective study in a group of Swedish women.

A prospective investigation of the course of breast-feeding was carried out in a group of 51 healthy, well educated Swedish women during the period three days to 18 months after delivery. The aims were to investigate the incidence, causes and consequences of perceived breast milk insufficiency (transient lactation crises), by relating this phenomenon to the infant's breast milk consumption and growth, and to the course of breast-feeding. It was found that every second mother experienced transient lactation crises on at least one occasion (the crisis group). The crises were mostly caused by emotional disturbances in the mothers (e.g. anxiety, stress and discomfort), or by the infant's refusal to suckle, by unmotivated crying, or by illness. Within the crisis group no significant difference was found between the infants' intake of breast milk during the crises compared with control measurements one week later. Nor had the crises any immediate impact on the growth of the infants. A comparison between the mothers with crises and those who did not experience any crises, revealed that the breast milk consumption among the infants in the crisis group was lower throughout with significant differences at three and five months. The infants in the crisis group also had a significantly lower weight at two, three, four and nine months, although both groups were above the NCHS mean. The reasons for initiating breast-feeding differed between the two groups. The crisis group tended to give infant-related reasons to a higher degree than the mothers in the non-crisis group who more frequently mentioned mother-related motives. The mothers with crises also showed a greater ambivalence during the lactation period and terminated the breast-feeding somewhat earlier. Consequently they also introduced taste portions and started the weaning significantly earlier. Some general findings revealed a wide variation in breast milk consumption, not only between infants but also in the same infant from one occasion to another. The total energy intake was almost the same for the partially breast-fed infants, receiving breast milk plus supplementary food, and those who were exclusively breast-fed. Although most mothers in both groups initiated the weaning in accordance with general recommendations, a wide variation was also found in the length of the weaning period. In some cases it lasted for more than five months.