Arachidonic acid metabolites and control of breathing in the fetus and newborn.

Considerable evidence indicates that prostaglandins participate in the control of breathing in the fetus, during parturition and at birth. Further studies are required to fully define the physiologic role of prostaglandins, their exact site of action, their mechanism of action and their interaction with other physiologic factors. With regard to prostaglandins and the control of breathing, currently available data are consistent with the following: the stimulatory effects of PGSI on fetal breathing movements are due to a decrease in PGE2; endogenous PGE2 inhibits fetal breathing movements during HV-ECoG; the site of action is at the lower pons or medulla; the rise in concentration of PGE2 with parturition may contribute to, but is not essential for, the decrease in fetal breathing movements at that time; it is likely that the decrease in circulating concentration of PGE2 contributes to the onset of continuous breathing at birth; although prostaglandins can affect ventilation in the newborn, their physiologic role, if any, at that time is not known.