[Kinetics of catecholamines in amniotic fluid implicated with onset of labor pain].

There are several controversies related to labor initiation in term. I therefore tried to analyse the relationship between the onset of labor and the dynamics of catecholamine-concentrations in amniotic fluid using the LC-EC method. Results are as follows. 1. Dopamine levels in amniotic fluid increased with gestational age. 2. Norepinephrine and Dopamine levels were higher in women with uterine contraction than in those without uterine contraction. 3. PGF2 alpha production in amnion increased significantly when it was incubated thirty minutes with CAs compared to that incubated only with Hanks' BSS. The PGE production rate in amnion was five or six times as great as that in PGF2 alpha. In conclusion, it is supposed that CAs in amniotic fluid may play a role in the initiation of uterine contraction.