Hormones of labour and birth
Images: Kindred Birth
The four main hormones of birth are oxytocin, prolactin, adrenalin and melatonin. There are other hormones that play a smaller role such as prostaglandin, but I will focus on the hormones that have a larger role in birth and how you can help (or hinder) their production:
Oxytocin is released from the pituitary gland located in the brain. It's called the hormone of love- it's released during sexual arousal, hugging, kissing and feeling safe with those we are close to. Both women and men can release it (men in smaller doses). Oxytocin also triggers and regulates contractions during labour and birth. It has a role in breastfeeding in milk let-down. Of all the hormones in the body, oxytocin probably gives us the greatest happiness in life. It is considered a "shy" hormone. In order to maximise its production for effective progress of labour, we need to feel safe, secure, warmth and quiet (think of how mammals birth in nature). I often tell women to replicate the environment baby was conceived in to help oxytocin flow.
Melatonin is our sleep hormone. The muscle tissue found in the uterus, becomes responsive to melatonin's cues or prompts during labour. Labour occurs primarily in the night or early hours of the morning due to the way melatonin synergises with oxytocin. It's important to consider how to encourage the flow of oxytocin and melatonin to aide your labour. What changes can you make to your environment? Turn the lights off or use dimmers. I've even had women use sunglasses in labour to keep the bright lights off their eyes and reduce the stimulation. Keep things quiet, reduce unnecessary attendants, conversations and interruptions.
Prolactin is known as the “mothering” hormone. It increases during pregnancy and peaks when labor starts on its own. If we look to nature, Prolactin in other mammals during pregnancy and after appears to be readying a woman’s body for breastfeeding. It may also be involved in labour progress and helping baby to adjust to life outside the womb. Prolactin is central to breast milk production and may help with the adjustments to motherhood and our maternal instincts.
Adrenalin is often referred to the enemy of the birth room- in that in inhibits oxytocin and endorphin production and sends women into "fight, flight or freeze response". When adrenalin is high during labour due to fears, unecessary stimulation by strangers and conversations, bright lights and unfamiliar environment it can contribute to a slowing of labour and a more painful labour. For labour to flow well and reduce adrenalin during labour, it is important to stay relaxed, comfortable, remove stimulation and breath deeply. There is a small window when adrenalin is useful though. Once our cervix is fully opened, a release of adrenalin helps us to stay alert for birthing baby, and also helps with the fetal ejection reflex to move baby down.