Integrated Concentrations of Prolactin in Breast-Feeding Mothers

Summary: Mean 24-hour integrated concentrations of serum prolactin (PRL) in 8 breast-feeding mothers (62 ± 10.4 μg/1) was significantly higher than in 4 control subjects (14.8 ± 3.3 μg/1). No correlation was found between the mean integrated concentrations and time after delivery or breast-feeding status. There was no relationship between the mean integrated concentration of PRL or the basal PRL and the frequency of feedings, the total suckling time, the mean interval between feedings or the longest interval between feedings in the 24-hour period. The study provides conclusive evidence for increased prolactin secretion in long-term puerperal lactation.