Aminotic fluid levels of 5-hydroxytryptamine and 5-hydroxyndoleacetic acid before and during labour.

Levels of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were measured in amniotic fluid obtained at membrane rupture during labour and at amniotomy before the onset of labour. The levels of both 5-HT and 5-HIAA were higher during labour. The implications of this finding are discussed.