When to Bear DownThe woman may be told to “push” when the presenting part appears at the vulva; to do so before then incurs the risk of the os not being fully dilated.
The natural urge to “bear down” is experienced by the woman when the presenting part reaches the pelvic floor, so then would seem to be the proper time for her to be encouraged to do so. If she is told to “push” as soon as the os is fully dilated and the head has not descended to the pelvic floor, she fritters away her energy and will have no strength left to push properly when the need arises to overcome the resistance of the perineum.
(Some authorities do not approve of encouraging the woman to make any expulsive effort and do not find prolongation of the second stage because of this.)
I’m amused at how accurate this is 40 years later and how little it resembles second stage protocols I’ve seen in hospitals lately. An OB telling a primip to push at 9cms “to dilate your cervix” would be the most egregious example, but in general there’s a lot of checking and checking and checking and then “Hurrah! You’re fully! Start pushing!” Definitely no waiting for descent.
In general, allowing women to push in whatever way seems best for them when the time comes is the best policy. There’s no need to direct women in how to push and when to push, since as is noted in the final paragraph above, it’s not necessary and may not even speed things up appreciably. It’s really the uterus doing the pushing after all, not a muscle we have a lot of conscious control over, unlike the abdominal muscles. Purple pushing, where a woman is told to hold her breath for a count of whatever while pushing is not good – can cause a drop in oxygenation, is very exhausting, and may not allow the time necessary for proper rotation to occur at specific points, perhaps causing shoulder dystocia, among other problems.
Most women pushing spontaneously and in response to their body’s cues do so while letting air escape, perhaps by grunting, groaning or letting air hiss out between their lips, instead of holding their breath completely, and instead of tucking their chin in to their chest (as is often recommended by birth professionals), may rotate their neck or drop their heads back at various points. This kind of pushing is still very effective at helping babies emerge, and there’s no need to make a birthing woman wrong if she’s not doing it the way a birth professional prefers.