When a mother arrives in hospital and is contracting, a vaginal examination is offered as standard.
Midwives depend on the information gathered - how dilated the cervix is found to be - as a reliable measure of progress.
Women (partners too), give huge import to this 'score', letting confidence soar or sink accordingly, and birth paths and decisions to be shaped by the number they get told. Hopes and hearts can hinge on this tiny piece of arithmetic.
But before routinely agreeing to an internal examination on admission, consider how random this number is and what it adds.
Firstly, how can a very specific number be especially accurate given labour is a continually moving, dynamic process?
How does a midwife confirming that a cervix is 3cm know if it has been that way for some time and the mother is tipping towards active labour, or only just there, with labour still a good way off?
Furthermore, labour's successful unfolding depends on multiple levers working in concert.
Gravity. Mother's position. Baby's position. Mother's emotional state. And of course the power and regularity of contractions in relation to these influences: strengthening and building because a companion helps her to feel deeply safe for example; or weakening and plateauing because a light goes on, or movement is restricted.
Dilation, quite literally, can turn on a tuppenny, so all this highly charged investment in what 0-10cm point exactly the cervix has reached isn't helpful.
It's not that it's never appropriate. Sometimes progress stalls. Morale or energy plummets. Or a medical concern will arise and a decision needs making. When there's a fork in the road, getting 'an idea' of what is going on (and it really is just an idea) can help to shed some light and inform a plan.
But by and large, the most accurate measure of all is when the mother can feel how the sensations are deepening, accelerating, and intensifying for herself. INSIDE her body.
The ground feels good. Noise needs making. Pressure is immense. If every so often there is a feeling of SHIFT and CHANGE, she is very very VERY likely to be opening and releasing her baby and won't need telling so.
It is true, that these feelings are not one hundred per cent reliable, as a baby's position can sometimes give the wrong message. But in such a case, stalling will eventually become apparent. An internal check then can add, and there is no harm done. Whereas...for a woman who is in deep and uncomplicated flow, a routine check can really, really easily disturb good progress.
Dilation scores, so often regarded as a harmless gauge/ incentive, arouse the intellect, trigger cognition - and bring labouring women to alert. And that's never a good thing. Consider the affect a big jolt of self-awareness has on sexual desire. Birth is no different.