Mechanism of reduction of newborn metabolic acidemia following application of a rule-based 5-category color-coded fetal heart rate management framework

Abstracts

Objective: We have reported a 7-fold reduction in newborn umbilical arterial (UA) metabolic acidemia after adoption of a rule-based 5-category color-coded fetal heart rate (FHR) management framework. We sought evidence for the relationship being causal by detailed analysis of FHR characteristics and acid–base status before and after training.

Methods: Rates of UA pH and base excess (BE) were determined over a 5-year period in a single Japanese hospital, serving mainly low-risk patients, with 3907 deliveries. We compared results in the 2 years before and after a 6-month training period in the FHR management system. We used a previously published classification schema, which was linked to management guidelines.

Results: After the training period, there was an increase in the percentage of normal patterns (23%), and a decrease in variable decelerations (14%), late decelerations (8%) and prolonged decelerations (12%) in the last 60 min of labor compared to the pre-training period. There was also a significant reduction in mean UA pH and BE in the groups with decelerations after introduction of the FHR management framework.

Conclusions: The adoption of this FHR management system was associated with a reduction of decelerations and metabolic acidemia, without a change in cesarean or vacuum delivery rates. These results suggest that the obstetrical providers were able to better select for intervention those patients destined to develop more severe acidemia, demonstrating a possible causal relationship between the management system and reduced decelerations and metabolic acidemia.

• Fetal BE
• fetal heart rate
• fetal pH

Acknowledgements

We thank all the nurses of Noda clinic for their earnest dedication for each delivery.

Declaration of interest

The authors report no decelerations of interest. The authors report no conflicts of interest. Funding was provided by institutional sources only.