Fetal monitoring during labor is crucial for detecting potential hypoxic situations that could lead to severe outcomes like cerebral palsy or peripartum death. The current standard, fetal heart rate (FHR) monitoring, is subjective and prone to variability, with limited accuracy in predicting neonatal acidosis or hypoxic ischemic encephalopathy. Secondary methods of foetal monitoring have been developed in an attempt to reduce unnecessary interventions due to continuous cardiotocography (CTG), and to better identify foetuses that are at risk of intrapartum acidosis.

Very few studies directly compared CTG with foetal scalp blood (FBS) and CTG only. Only one randomised controlled trial (RCT) was published in the 1970s and had limited power to assess neonatal outcome. Direct and indirect comparisons conclude that FBS could reduce the number of caesarean deliveries associated with the use of continuous CTG. Recent randomized trials (FLAMINGO and FIRRST trial) examining the role of FBS in reducing cesarean sections and operative deliveries have yielded inconclusive results due to low recruitment.

The main drawbacks of FBS are its invasive and discontinuous nature, the risk of contamination, and the need for a sufficient volume of foetal blood for analysis, especially for pH measurement.

While FBS remains recommended in some guidelines, its use is declining in favor of improved FHR interpretation. The debate continues on its clinical utility, with a consensus emerging that FBS should be reserved for specific cases where its predictive value can guide decision-making, requiring ongoing research to better define its role in obstetric practice.