Hypergastrinemia of newborns and infants during breast-feeding

We determined gastrin concentrations in newborns and their mothers both before and during lactation.

Twenty-five women who had uncomplicated pregnancies with normal vaginal delivery of healthy infants at term participated in the study. Twelve preterm neonates with low birth weight (LBW) were also studied. Gastrin levels were determined by radioimmunoassay in amniotic fluid and in serum of both the neonates and their mothers at birth and during breast-feeding. Serum levels of gastrin and prolactin (PRL) were measured in the mothers before and after tactile self-stimulation of the breast.

In normal newborns, gastrin levels in cord sera were significantly higher than levels in maternal blood and amniotic fluid at birth. However, gastrin cord sera in LBW newborns was lower than in the normal neonates. Nursing resulted in an increment of serum gastrin levels in the infants and mothers; this rise was similar in the 3 postpartum weeks tested. Tactile stimulus of the mother's nipple resulted in increases of both gastrin and PRL.

Newborns at term show significantly higher gastrin levels than do LBW neonates, which may indicate differences in development of the gastrointestinal system. Breast-feeding induced gastrin secretion in both mothers and infants, confirming the presence of an active vagal reflex. In addition, tactile stimulation of the nipple increased gastrin and PRL levels in the mothers. Our data suggest that LBW neonates have deficient production of gastrin, which in turn may indicate an undeveloped gastrointestinal system. An early enteral feeding triggers the postnatal increase in concentrations of gut hormones.