Diurnal rhythms of fetal and maternal heart rate in the baboon

• Published in: Early human development 1999-07, Vol.55 (3), p.195-209
• Main Authors: Stark, Raymond I., Garland, Marianne, Daniel, Salha S., Tropper, Pamela, Myers, Michael M.
• Format: Article
• Language: English
• Subjects: Amniotic Fluid - physiology; Animals; Baboon and fetus; Biological and medical sciences; Blood Pressure - physiology; Circadian Rhythm; Diurnal rhythms; Female; Fundamental and applied biological sciences. Psychology; Heart Rate - physiology; Heart rate and variability; Heart Rate, Fetal - physiology; Hemodynamics. Rheology; Male; Papio - physiology; Pregnancy; Pregnancy Outcome; Pregnancy, Animal - physiology; Reference Values; Vertebrates: cardiovascular system
• ISSN: 0378-3782; 1872-6232
• DOI: 10.1016/S0378-3782(99)00014-6

To investigate the organization of diurnal rhythmicity during gestation, the relationship between daily cycles of maternal and fetal heart rate were measured in long-term studies of healthy chronically instrumented pregnant baboons. In each of six pregnancies, hourly mean values over a 168 h time series were obtained during a 7 to 10 day interval between 135 and 160 days of gestation. Data were modeled by a least squares fit to a cosine function with a period of 24 h. Hourly mean heart rate in the fetus ranged from 161 to 172 bpm (167.9±0.6 bpm), and the mother from 105 to 125 bpm (107.9±1.4 bpm). The amplitude of the daily fluctuations were 15 to 25 bpm for the fetuses and 25 to 60 bpm for the mothers. The relation between time series data and model estimates were significant ( P