Introduction: Intrapartum fetal monitoring is essential for the identification of fetal hypoxia to reduce perinatal morbidity and mortality. Cardiotocography is associated with low specificity for fetal acidosis and poor perinatal outcome leading to unnecessary operative deliveries. ST waveform analysis of the fetal electrocardiogram has been shown to be a promising adjunctive intrapartum assessment tool. We aim to present the pathophysiology, the role of intrapartum monitoring and the practical usage of this relatively new technology in our review. Methods: An electronic search of Medline and OVID was carried out, followed by a manual search of the references identified by the electronic search. Results: The incorporation of ST waveform analysis to cardiotocography has been shown to reduce the rates of neonatal metabolic acidosis, moderate and severe neonatal encephalopathy, thus improving perinatal outcome. The reduction in operative delivery rates due to fetal distress is also significant. The pathophysiology and practical usage of this technology were discussed. Conclusions: With more accurate identification of fetal hypoxia and reduction of unnecessary intervention rates, incorporation of ST waveform analysis of fetal electrocardiography into cardiotocography can improve the standard of intrapartum fetal monitoring.
Intrapartum fetal monitoring is essential for the identification of fetal hypoxia to reduce perinatal morbidity and mortality. Although electronic fetal heart rate monitoring leads to reduction in the rates of neonatal seizures, no significant differences were observed in Apgar scores, admissions to neonatal intensive care units and perinatal deaths.1 Low specificity for fetal acidosis and poor perinatal outcome provided by cardiotocography leads to unnecessary operative deliveries.1,2 Subjective and incorrect interpretation of cardiotocography data is a common finding in intrapartum event-related asphyxia.3,4 In a review of 110 cases of obstetric litigation for cerebral palsy, Symonds and Senior5 found that 70% of these claims were based on cardiotocography abnormalities and their interpretation. Computerised cardiotocography may offer more objective and accurate information of intrapartum fetal health assessment6-8 but randomised controlled trials in this field are very limited.
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