Introduction of central fetal monitoring and impact on neonatal outcome - a retrospective observational cohort study.

INTRODUCTION

Cardiotocography (CTG) is used for fetal surveillance to prevent asphyxia related neonatal outcomes during pregnancy and delivery. In Sweden, all delivery wards have transitioned from CTG registered and printed on paper inside the delivery room, to digital central fetal monitoring where CTG is visible both in the delivery room and on distance for multiple observers. We aimed to evaluate whether the transition from CTG on paper to central fetal monitoring has affected neonatal morbidity.

MATERIAL AND

METHODS

The study was conducted as a retrospective cohort study. Data from 8577 deliveries in Östersund, Sweden were extracted from medical records. The study population was divided into two cohorts, one where the CTG registration during delivery had been printed on paper (Cohort I, January 2012-December 2015), and one where digital central fetal monitoring was used (Cohort II, July 2016-December 2019). The cohorts were compared regarding the incidence of neonatal metabolic acidosis (umbilical artery pH <7.05 and base deficit >12 mmol/L) as the main outcome, and secondary outcomes such as Apgar score at 5 min of age, the incidence of neonatal resuscitation, and the incidence of emergency cesarean and instrumental vaginal birth due to suspected fetal hypoxia.

RESULTS

The incidence of metabolic acidosis was 0.5% in Cohort I and 0.6% in Cohort II, odds ratio (OR) 1.27, 95% confidence interval (CI) 0.67-2.40, p = 0.46. There were no statistically significant differences in any of the secondary neonatal outcomes. Adjustment for potential confounders did not alter the estimates. The cohorts differed in the incidence of inductions of labor; 18.8% in Cohort I vs 23.2% in Cohort II, p < 0.0001, and the use of oxytocin; 50.2% vs 60.0%, p < 0.0001, both of which were more frequent in Cohort II. The incidence of instrumental vaginal births due to suspected fetal hypoxia was lower in the cohort with digital CTG; 3.6% vs 2.6%, p = 0.01.

CONCLUSION

We observed no difference regarding the incidence of neonatal metabolic acidosis or other neonatal outcomes between the cohort that had CTG registered and printed on paper, and the cohort with digital central fetal monitoring.