Bursian A V, Konstantinova N N, Natsvlishvili V V, Voskresenskiĭ V O
Zh Evol Biokhim Fiziol. 1992 Sep-Oct;28(5):591-5.
Fetal motor bursts were recorded in pregnant women at 11-18, 20-24 and 30-32 weeks of pregnancy. It was stated that spontaneous motor activity in human fetus is similar to autogenic periodic motor excitation observed in other species of vertebrates, i.e. presence of the main rest-activity circles with a period near 1 minute, the existence of rhythmic components with 6-8-second intervals during active phases and decreasing of quantity of excitation bursts with age.