Intrapartum deceleration and acceleration areas and the risk of neonatal
encephalopathy, a retrospective case-control study
Abstract
Objective: To investigate whether an association exists between
deceleration and acceleration areas on continuous fetal cardiotocography
(CTG) and neonatal encephalopathy (NE). Design: A retrospective
case-control study. Setting: A single tertiary medical center with over
15,000 births a year. Population: All deliveries complicated by neonatal
encephalopathy in our center during the study period, with two controls
for every case, matched by gestational age and cord blood pH. Methods:
We compared CTG characteristics of low-risk pregnancies (35 weeks
gestation or more), complicated by moderate to severe NE with matched
controls. We analyzed the intrapartum CTG recordings by calculation of
the deceleration and acceleration areas. Main outcome measure:
Deceleration and acceleration areas and the ratio between the two.
Results: During the period between 2013 and 2019, we identified 95 cases
of low-risk pregnancies that were complicated by moderate to severe NE
in our center. Thirty-three (34.7%) deliveries were excluded, mostly
due to an insufficient duration of the CTG recordings. The remaining 62
cases were matched with 123 controls. We found that NE was significantly
associated with an increased total deceleration area, a decreased total
acceleration area and a lower acceleration-to-deceleration ratio.
Conclusions: In our population, NE was significantly associated with
increased total deceleration area, decreased total acceleration area and
a lower acceleration-to-deceleration ratio, irrespective of cord blood
pH. Development of a computerized real-time analysis of fetal heart rate
tracings may contribute to making these measurements a more valid
clinical tool.