Breastfeeding Hormones Explained

​Oxytocin

Oxytocin is commonly referred to as 'the happy hormone’. It plays a BIG part in the let-down reflex and is released from the posterior pituitary gland. Let-down reflex refers to the burning, tingling or cramping feeling you may experience before milk is able to be ejected from the nipple. Oxytocin is also responsible for the uterine contractions you may feel when breastfeeding. If you have had a very stressful and painful labour or are in lots of pain post birth with stitches or after a c-section for days and weeks after, this can also inhibit your supply of oxytocin. This can jeopardise the milk supply as let down reflex may not be stimulated adequately. Oxytocin is responsible for the contraction of the alveoli cells within the breast therefore letting them be able to release milk. Similarly, if you have had a traumatic labour with blood loss, you may be put on a Synto drip (synthetic oxytocin) and this may also interferer with the natural production of oxytocin in the long term and disrupt the let-down reflex.

Prolactin

Prolactin is the hormone responsible for the primary production of milk. Prolactin is released from the anterior pituitary gland. During lactogenisis stage one milk production is hormonally driven, so that the first milk (colostrum) is ready for the baby on arrival. This prolactin hormone starts to be released halfway into pregnancy, which is when you start to feel slight changes in the breast. Prolactin stays high if you are breastfeeding and if you stop the levels drop. Although in some women, even if they continue to breastfeed their prolactin levels can sometimes drop to the normal level again. Three to five days after the baby is born the breasts enter lactogenisis stage two, where the breasts become fuller with milk. When the baby is born the gut is full of meconium which needs to pass, which is why in lactogenisis stage one only a small amount of milk is produced as the baby needs to pass these stools before they start feeding on a more plentiful supply by days three to five.

FIL- Feedback Inhibitor of Lactation 
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FIL tells the breasts to stop producing milk in the event the breasts are full. Normally within the first couple of weeks you want to keep FIL low so that the breasts produce enough milk and meet the needs of the baby, this is done by feeding at regular intervals. However, with breasts that are too full, feedback inhibitor of lactation hormone is released and this tells the breasts to stop producing milk which may jeopardise supply. If the Mother does not feed regularly the breasts remain semi full and FIL remains in contact with the alveoli cells within the breast and therefore tells the breasts to keep milk supply to a minimum. Therefore we want to encourage an emptier breast after a feed to keep FIL low and keep supply of milk in demand.