The effect of uterine contractions on intrapartum fetal heart rate analyzed by a computerized system.
OBJECTIVE
Our goal was to assess the effect of uterine activity on fetal heart rate indexes during the active phase of labor with a computerized fetal heart rate monitoring system.


METHODS
Twenty-six healthy women were studied in active labor without analgesia. Fetal heart rate was analyzed by a computerized system (Sonicaid, System 8000), providing a numeric analysis of the fetal heart rate indexes. Montevideo and Alexandria units were used for quantitative assessment of contractions.


RESULTS
A significant correlation was found between Montevideo units and short-term variation (r = -0.62, p < 0.001), episodes of high (r = -0.48, p < 0.01) and low (r = 0.58, p < 0.01) fetal heart rate variation, and frequency of large accelerations (r = -0.49, p < 0.01). A significant correlation was also found between Alexandria units and short-term variation (r = -0.645, p < 0.001), episodes of high fetal heart rate variation (r = -0.58, p < 0.01), and frequency of large accelerations (r = -0.49, p < 0.01).


CONCLUSIONS
In active labor fetal heart rate variability is significantly affected by the intensity and duration of contractions.
Zimmer
E Z
EZ
Department of Obstetrics and Gynecology, Rambam Medical Center, Technion Faculty of Medicine, Haifa, Israel.
Paz
Y
Y
Copel
J A
JA
Weiner
Z
Z
D016362:Analgesia, Obstetrical; D036861:Delivery, Obstetric; D005260:Female; D006340:Heart Rate, Fetal / Q000502:physiology*; D006801:Humans; D009716:Numerical Analysis, Computer-Assisted; D011247:Pregnancy; D014590:Uterine Contraction / Q000502:physiology*