Fetal breathing, gross fetal body movements, and maternal and fetal heart rates before spontaneous labor at term.

In order to examine patterns of fetal breathing and body movements and fetal and maternal heart rates near term, we studied 28 healthy pregnant women over 24-hour observation intervals at 38 to 40 weeks' gestation. There was a significant decrease in the incidence of fetal breathing movements during the last 3 days before spontaneous parturition at term, but there was no significant difference in the patterns of gross body movements or fetal and maternal heart rates. We concluded that, prior to spontaneous labor at term, there is a normal decrease in the incidence of fetal breathing movements but no similar change in the incidence of gross fetal body movements. This study suggested that the presence of gross fetal body movements is a more consistent index of fetal health before spontaneous labor at term.