The effect of nursing on the brain activity of the newborn

Objective: To determine whether nursing influences brain activity in the newborn and whether there are differences in this respect between breast- or bottle-feeding and pacifier sucking. Study design: Fifty unselected volunteer mothers and their healthy full-term infants, under care in the maternity ward after delivery, served as subjects. Thirty mother-infant pairs were studied in relation to breast-feeding and 20 to bottle-feeding and pacifier sucking. Breast-fed infants were studied between the 1st and 7th day after delivery (mean +/- 2.7 days) and the infants in the bottle-fed group between the 1st and 8th day after delivery (mean +/- 3.3 days). Methods: Qualitative and quantitative electroencephalogram (EEG), electro-oculogram, submental electromyogram, and electrocardiogram were recorded before, during and after breast- and bottle-feeding and pacifier sucking. Results: The amplitude of the EEG increased significantly during breast-feeding in the posterior cortical areas in both hemispheres with a slight predominance on the right. Bottle- feeding caused a similar, but somewhat less marked change. When the breast- and bottle-fed infants were compared, a significant difference was found in only one parameter of the 84 studied. Pacifier sucking had no significant effects on EEG activity. Conclusion: Nursing effects a change in the brain activity of the newborn. The cortical response to nursing is most probably a result of activation of the neurohumoral mechanisms related to hunger and satisfaction, including the hypothalamic, limbic, and other brain stem structures, which also regulate the sleep-wake cycle and modulate the level of cortical activity with respect to attention and vigilance.