The concept of dilation of the cervix from 0-10cms during labour is unphysiological when we understand labour as a series of responses between mother and baby.
It starts at the very end of pregnancy, when space in the womb is tight and the baby’s head starts to descend into the brim of the pelvis. Pressure from the baby’s head on the lower segment of the uterus and the cervix has the effect of stimulating the release of prostaglandins – softening hormones produced within the tissues themselves – so they become ready to open around the baby’s descending head.
A great affirmation for the mother is:
My baby is moving DOWN and my body is SOFTENING AND OPENING.
Meanwhile oxytocin continues to be released in pulses into the mother’s blood stream and travels to her uterus via the uterine blood vessels. Each ‘pulse’ results in a contraction and this is how the labour gets its rhythmic nature of waves that come and go. Work followed by rest – in a continuous rhythm.
Oxytocin is absorbed into special receptors that are most concentrated on the upper segment of the uterus, causing the long fibres that go up and over the top of the uterus to shorten and tighten (contract).
When this happens they push the baby down a little every time and simultaneously pull up the softened circular fibres at the base of the uterus – absorbing them up into the body of the uterus. I call this the ‘push-pull’ action of the uterus.
To simplify your understanding of the action of the uterus, I ask you to visualise the pulsatile actions of a jellyfish swimming in the deep ocean.
With each contraction the uterus becomes thicker at the top, staying snug around the baby’s body and thinner at the base.
With continual pressure from the baby’s descending head, the cervix is drawn up, all the way around the baby’s head as far as the top of the ears and the eyebrows – so most of the baby’s head will have emerged from the womb by the end of the first stage of labour.
The head then stretches open the top of the vagina – and this is one of the stimulae for the birth reflex.
The thickened, contracted uterus, snug around the baby’s body is now ready to push the baby out!
A great affirmation for the mother at end of labour is:
My body is SOFT and OPEN and I am preparing to release my baby