Behavioral states in the human fetus during labor.

Behavioral states in the near-term human fetus have been described during pregnancy. The aim of this study was to observe whether these same states are present during labor. Nine patients with uncomplicated singleton pregnancies participated. Fetal heart rate and uterine contractions were recorded. Fetal eye, mouth, rotation, and retroflexion of the head were observed by real-time ultrasound. Fetal movements were recorded with coded event-markers. Behavioral states were identified by the movement pattern. A total of 13 ultrasound observations, varying from 25 to 66 minutes, were obtained. Optimal viewing was present at least 60% and on the average 80% of the time. State 1F (quiet sleep), state 2F (active sleep), and state 3F (quite awake), as well as a total of 10 state changes, were identified during labor in spite of increasing contractions and/or ruptured membranes. These observations demonstrate existence of alternating behavioral states in the healthy term fetus during labor.