Antepartum computerized CTG and neonatal acid-base status at birth

Abstract

Objective: To assess the correlation between individual computerized cardiotocography (cCTG) variables and acid-base status at birth before the first breathing in uncomplicated term pregnancy delivered by cesarean section.

Study design: A retrospective cohort study.

Subjects and methods: Seventy singleton normal pregnancies delivered by elective cesarean section. The last antepartum cCTG performed within 4 h from delivery by the System 8002 (Oxford Sonicaid, UK) was correlated to umbilical blood gas analysis (UBGA) values (AVL compact 2 analyser). Considering blood gas analysis values as dependent and individual cCTG parameters as independent variables the best regression subsets followed by a backward stepwise linear regression was used.

Results: There was no significant correlation of cCTG parameters with any of the values of blood gas analysis. However, when neonatal conditions, as expressed by arterial pH > 7.20, Becf > - 4.0 mmol/l and Apgar score at 5 min > 7, were taken as an end-point, they could be predicted by Acc15 and FM/hour (sensitivity: 35%, positive predictive value: 92%, cut-off > 7 and 67%, 92%, > 21, respectively).

Conclusion: In uncomplicated pregnancies, the prospect of a vigorous newborn seems particularly associated with the presence of Acc > 15 and FM/hour > 21.