Periodic fetal heart rate decelerations during 6 hours' hypoxemia induced in goats.
OBJECTIVE
To determine if fetal heart rate (FHR) decelerations periodically occur with uterine contractures during 6 hours' induced hypoxemia in goats.


METHODS
In five chronically catheterized goat fetuses at 125-130 days' gestation, incidence of FHR decelerations was compared between 6 hours' control time and 6 hours' induced hypoxemia with two-way ANOVA and Duncan's multiple range test. Three other fetuses were used as controls for circadian rhythm.


RESULTS
Fetal PaO2 was significantly decreased from 26.1 to 16.3 mmHg without acidemia. During hypoxemia, 42 decelerations were induced along with 5 initial decelerations during the acute phase hypoxemia. Incidence of decelerations increased significantly from 0.07 +/- 0.15 per hour in 6-hour controls to 1.40 +/- 0.28 per hour during 6 hours' induced hypoxemia. Short-term variability and long-term variability of the 42 decelerations were significantly increased. These variabilities were also increased during the 5 initial decelerations. Frequency of uterine contractures did not change during hypoxemia. There was an observable association of FHR decelerations with uterine contractures during hypoxemia.


CONCLUSIONS
Fetal heart rate decelerations occurred periodically in association with uterine contractures during induced 6 hours' hypoxemia, which were characterized by slow onset and recovery with increases in variability.
Sameshima
H
H
Department of Obstetrics and Gynecology, Miyazaki Medical College, Japan. rayjun@post1.miyazaki-med.ac.jp
Ikenoue
T
T
Kamitomo
M
M
Sakamoto
H
H
D000818:Animals; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005315:Fetal Diseases / Q000503:physiopathology*; D005865:Gestational Age; D006041:Goats; D006340:Heart Rate, Fetal; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000150:complications*; D009584:Nitrogen / Q000008:administration & dosage; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D014590:Uterine Contraction
D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen