Alterations in polyamine levels in amniotic fluid, plasma and urine during normal pregnancy.

Polyamines have a close relationship with rapid cell proliferation. We measured polyamine levels in amniotic fluid, maternal plasma and urine during normal pregnancy. Plasma putrescine, spermidine and spermine gradually increased in the third trimester and reached the highest concentration at the end of pregnancy. There was a significant correlation between the level of these polyamines and the level of plasma estradiol and progesterone. In urine, putrescine and spermine increased with the progress of gestation and reached the highest level during the 8th to 10th months of gestation. In amniotic fluid, putrescine and spermidine concentrations were significantly high in the first trimester and decreased in the other trimesters, whereas spermine showed no significant change. Polyamine concentrations in maternal plasma and urine appear to reflect not only fetal metabolic changes but also the metabolic changes of the pregnant women, and to be influenced by several hormones which increase during pregnancy. Polyamines in amniotic fluid mainly reflect activated fetal metabolism and may be useful as biochemical indicators of fetal growth.