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Updated: Sep 22, 2026
Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Correlation between gestational age and fetal activity periods
Cyclic patterns of active and quiet fetal activity were evaluated in 36 clinically normal gravidas between 27 and 42 weeks of gestation. All infants were subsequently delivered between 37 and 42 weeks of gestation, were clinically normal and of appropriate weight for gestational age. Active-quiet cycles occurred less frequently and were of longer duration with increasing gestational age. Regression analysis of the number of active-quiet cycles with gestational age yielded a correlation coefficient of 0.52 (p less than 0.01). The similarity of fetal active-quiet cycles and active and quiet sleep cycles observed after birth is noted.
Cyclic patterns of active and quiet fetal activity were evaluated in 36 clinically normal gravidas between 27 and 42 weeks of gestation. All infants were subsequently delivered between 37 and 42 weeks of gestation, were clinically normal and of appropriate weight for gestational age. Active-quiet cycles occurred less frequently and were of longer duration with increasing gestational age. Regression analysis of the number of active-quiet cycles with gestational age yielded a correlation coefficient of 0.52 (p less than 0.01). The similarity of fetal active-quiet cycles and active and quiet sleep cycles observed after birth is noted.
