[Fetal scalp pH during labor: Which threshold for intervention?]

Area of Science:

• Obstetrics and Gynecology
• Neonatal Medicine
• Perinatal Research

Background:

• Consensus is lacking on the optimal scalp pH threshold for deciding on rapid birth during abnormal fetal heart rate.
• Different maternity units may employ varying scalp pH decision thresholds, potentially impacting clinical outcomes.

Purpose of the Study:

• To compare neonatal outcomes and cesarean delivery rates between two maternity units utilizing different scalp pH decision thresholds.
• To evaluate the impact of a 7.20 versus a 7.25 scalp pH threshold on neonatal morbidity and operative delivery rates.

Main Methods:

• A retrospective comparative study involving two level III maternity units from January 2013 to May 2014.
• One unit used a scalp pH threshold of 7.20, while the other used 7.25.
• Adverse neonatal outcome was defined by a composite endpoint; cesarean risk was assessed via multivariate analysis.

Main Results:

• No significant difference in adverse neonatal outcomes (25% vs. 30.1%) or average pH at birth was observed between the two groups.
• The 7.20 scalp pH threshold group had a higher incidence of base excess (BE) less than -12 (7% vs. 0%).
• The maternity unit with the 7.25 scalp pH threshold exhibited a higher cesarean rate (adjusted OR=2.23).

Conclusions:

• A scalp pH decision threshold of 7.20 appears reasonable and may lead to a reduction in cesarean rates.
• Further studies are warranted to confirm that a 7.20 threshold does not elevate the risk of severe neonatal acidosis.
• The findings suggest potential for optimizing intervention thresholds in fetal heart rate monitoring.