Periods of Activity and Inactivity in the 12-to 16-Week Fetus

Abstract

Active and inactive periods in four 12-to 16-week low risk human fetuses were studies. These periods are interpreted as precursors to the state parameter of fetal body movements. Adequate reliability on scoring videotapes of fetal activity and inactivity was achieved, but extensive training with explicit protocols was required. Results suggested that there was an increase in among of fetal movement form 12 to 14 weeks, followed by a significant decrease in movement from 14 to 16 weeks. There was a significant increase in cycles per minute from 12 to 16 weeks. Early fetal movement was descriptively compared to newborn infant movement using a Brazelton Neonatal Behavioral Assessment Scale.