The Fetal Ejection Reflex.
In the final stages of an undisturbed labour, the fetal ejection reflex is triggered, causing powerful, involuntary, expulsive contractions that enable us to birth our babies. As our baby moves through the pelvis, they will stimulate the nerve endings and initiate this incredible response within our bodies. At this point in labour you will have a huge surge in adrenalin, again contributing to initiating the fetal ejection reflex (thought to be so we have both energy for this moment, and that we become alert immediately after birth in order to protect our newborn babies!). In hospital settings, we sometimes see an external trigger for adrenalin production (such as discussions around instrumental birth or new people entering a room) cause this response too, as our bodies 'sense danger' and decide that baby is better out than in! It's important to note that surges in adrenalin earlier on in labour would have a different effect entirely, and usually causes labour to slow down or ‘stall’, because evolutionally the safest thing to do would be to ‘get away from the danger’.. so I wouldn’t recommend external triggers for adrenalin!!
This surge in adrenalin (the hormone of fear) can also explain why we sometimes feel or express 'panic' during transition, it's our outward response to our body's way of preparing hormonally for what is about to happen. For some women this comes with an irresistible urge to bear down and 'push', for others the reflex takes over entirely.
The simplest way to describe what the fetal ejection reflex feels like, is remembering a time where you suffered with food poisoning and needed to be sick, nothing would stop you being sick, it was just HAPPENING! It's basically that... in reverse.
If birth is disturbed too much, be that by intervention, conversation, location or something else, we run the risk of interfering with the body's natural flow of hormones, meaning we miss hugely helpful, natural mechanisms such as this! It's therefore important that we think carefully about the environment and support we have around us during birth. We have the PERFECT physiological system already in place, we simply need to let it do it's job!
Newton, N. (1987). The Fetus Ejection Reflex Revisited. Birth. 14(2). 106-108.
Odent, M. (2000). Insights into pushing. The second stage as a disruption of the fetus ejection reflex. Midwifery Today. 55. 12.
Odent, M. (1987). The fetus ejection reflex. Birth. 14(2). 104-105.
Ventolini, G. Yaklic, J. Galloway, M. Hampton, M. Maher, J. Obstetric vulvar lacerations and postpartum dyspareunia. J Reprod Med. 59 (11-12). 560-565.
Odent, M. (2010). First stage: preparing the fetus ejection reflex. 95. 35.
If you are interested in taking the next step to a positive birth, Positively Birthing Hypnobirthing and Antenatal Classes run throughout Surrey and SW London- areas including Surbiton, Esher, Teddington, Cobham, Twickenham, St Margarets, Thames Ditton, Molesey, Richmond, Wimbledon, Kingston, Sunbury, Epsom, Ewell, and beyond. All bookings can be made here.