Perhaps the best-known birth hormone is oxytocin, the hormone of love, which is secreted during sexual activity, male and female orgasm, birth and breastfeeding. Oxytocin engenders feelings of love and altruism; as Michel Odents says, “Whatever the facet of Love we consider, oxytocin is involved. (1)
Oxytocin is made in the hypothalamus, the ‘master gland’ deep in our brains, and stored in the posterior pituitary, from where it is released in pulses. It is a crucial hormone in reproduction and the ejection reflexes: i.e. the sperm ejection reflex with male orgasm, and the corresponding sperm introjection reflex with female orgasm. Michel Odent refers also to the’ foetal ejection reflex’ at birth – describing the powerful contractions at the end of an undisturbed labour, which birth the baby quickly and easily; (2) then the placental ejection reflex and the milk ejection, or let-down reflex in breastfeeding.
As well as reaching peak levels in each of these situations, oxytocin is secreted in large amounts in pregnancy, helping nutrient absorption, reducing stress and conserving energy by making the pregnant woman more sleepy. (3) Oxytocin also causes the rhythmic uterine contractions of labour, and levels peak at birth through
stimulation of receptors in a woman’s lower vagina as the baby descends.(4) The high levels continue after birth, culminating with the birth of the placenta, and the gradually subside.(5)
The baby also produces oxytocin during labour, perhaps even initiating labour,(6) so that in the minutes after birth, both mother and baby are bathed in an ecstatic cocktail of hormones. At this time ongoing oxytocin production is enhanced by skin-to-skin and eye-to-eye contact and by the baby’s first suckiling. Good levels of oxytocin also protect against postpartum haemorrhage by ensuring good uterine contractions.(7) In breastfeeding, poxytocin mediates the let-down reflex and is released in pulses as the baby suckles. During the months and years of lactation, oxytocin continues to keep the mother relaxed and well nourished. It is a very efficient anti-stress situation which prevents a lot of disease later on.