Neuroendrocrinology of the MotherC h i l d I n t e r a c t i o n

During pregnancy, the role of the mother and the placental hormones are to sustain pregnancy and the role of the fetus is to promote fetal growth and development. During birth, the mother and baby “are exposed to interactive sensory stimulation, which triggers the release of a cascade of hormones… the release of hormones caused by labour and birth is important for the adaptation to extra-uterine life”. Vaginal delivery was said to potentially influence the pattern of breastfeedingrelated oxytocin and prolactin release. Suckling induces the release of prolactin to stimulate milk production and oxytocin for milk ejection. Pregnancy, labour and s u c k l i n g st i m u l ate a n d a l te r t h e morphology of oxytocinergic neurons. These neurons project to various areas within the mother’s brain distributing oxytocin and influencing maternal physiology, endocrinology and behaviour. Oxytocin mediates many mechanisms of the mother and infant’s physiology. Some which were discussed included the ejection of milk which transfers warmth and calmness to the infant, lactation which transfers nutrients from maternal stores to the milk, vagal stimulation from suckling release GI hormones promoting digestion and anabolic metabolism in the mother and a reduction in the mother’s cortisol and blood pressure. This may suggest it creates an anti-stress effect and inhibits the sympatho-adrenal system. The effect of suckling and its influence on the baby was also discussed. Interestingly, the author reviewed a paper which revealed that the nonnutritive sucking enhances growth rate in premature infants without caloric intake and shortens hospital stay. Also, sucking a pacifier was discussed to reduce movement and exert a sedative effect on the infant. Sucking also releases GI hormones which may contribute to the infant’s growth and development. Suckling allows for the interaction between mother and infant via skinto-skin contact, olfactory, visual and auditory signals. The author discussed several studies assessing this contact in rats and there was an interesting revelation whereby rat pups, when separated from their mothers became distressed, cortisol levels elevated and growth hormone levels decreased. These changes were reversed by tactile stimulation. This may suggest that cutaneous stimulation reduces sympatho-adrenal activity. A study r e v i e w e d r e fl e c t e d o n t h e supplementary sensory stimulation in p r e m a t u r e i n f a n t s a n d i t s enhancement with their weight gain and their physiological and behavioural maturation. These changes can be attributed to the neuro-endocrine effe ct s o f s t i m u l a t i o n o f t h e somatosensory afferents. The changes in hormonal levels during breastfeeding was said to influence maternal behaviour. Estrogen, progesterone, FSH and LH decrease and prolactin increases through breastfeeding. This may potentially create a decrease in the interest of sexual activity and social desirability. Newborn children need tactile, kinaesthetic , v e s t i b u l a r a n d proprioceptive stimulation to grow and develop physiologically and psychologically. Receiving a normal mother-infant interaction provides this stimulation. This stimulation also influences hormonal changes in both the infant and mother. As practitioners our best recommendation is to advise on parent-infant time.