Is amniotic fluid prolactin an osmoregulatory hormone of clinical importance

: The present paper reports on the amniotic fluid prolactin concentrations in 61 pregnancies with undisturbed amniotic fluid volume from the 17th to the 41st week of pregnancy. The amniotic fluid prolactin concentrations reach a peak in the 19th week of pregnancy with a slight decrease to the 21st week. After a plateau from the 23rd to the 31st week of pregnancy, prolactin concentrations decrease to very low levels in late gestation. In pregnancies with disturbed amniotic fluid volume the prolactin concentrations are pathologically changed in comparison with "normal" pregnancies. The authors conclude that the amniotic fluid prolactin concentrations have a characteristic profile depending on the stage of pregnancy. From the pathologic prolactin concentrations in patients with hydramnios and otherwise pathologic pregnancies it may be concluded that prolactin is a clinically relevant osmoregulatory hormone for humans too.