There are four main factors that prevent the baby from inhaling water at the time of birth:
1. Prostaglandin E2 levels from the placenta which cause a slowing down or stopping of the fetal breathing movements. When the baby is born and the Prostaglandin level is still high, the baby's muscles for breathing simply don't work, thus engaging the first inhibitory response.
2. Babies are born experiencing mild hypoxia or lack of oxygen. Hypoxia causes apnea and swallowing, not breathing or gasping.
3. Water is a hypotonic solution and lung fluids present in the fetus are hypertonic. So, even if water were to travel in past the larynx, they could not pass into the lungs based on the fact that hypertonic solutions are denser and prevent hypotonic solutions from merging or coming into their presence.
4. The last important inhibitory factor is the Dive Reflex and revolves around the larynx. The larynx is covered all over with chemoreceptors or taste buds. The larynx has five times as many as taste buds as the whole surface of the tongue. So, when a solution hits the back of the throat, passing the larynx, the taste buds interprets what substance it is and the glottis automatically closes and the solution is then swallowed, not inhaled.
WHEN SHOULD I GET INTO THE WATER?
A woman should be encouraged to use the labor pool whenever she wants. However, if a mother chooses to get into the water in early labor, before her contractions are strong and close together, the water may relax her enough to slow or stop labor altogether. That is why some practitioners limit the use of the pool until labor patterns are established and the cervix is dilated to at least 5 centimeters.
There is some physiological data that supports this rule, but each and every situation must be evaluated on its own.
Some mothers find a bath in early labor useful for its calming effect and to determine if labor has actually started. If contractions are strong and regular, no matter how dilated the cervix is, a bath might be in order to help the mother to relax enough to facilitate dilation.
Therefore, it has been suggested that the bath be used in a
Here is a valuable source of information to help you to make an informed choice for your birth.