Assessment of Second-stage Fetal Heart Rate Patterns and Its Association with Neonatal Outcome

Background:The aim of intrapartum surveillance is to identify the impending signs of fetal hypoxia, thereby helping to prevent fetal acidemia by facilitating prompt clinical decisions.Materials and methodology: This is a prospective observational study in which low-risk term antenatal patients with singleton pregnancies, vertex presentation, and normal fetal heart rate (FHR) tracings in the first stage of labor were included.Cardiotocography (CTG) was taken in the second stage of labor, and neonatal cord blood acid-base samples were taken and correlation between the two was observed.Results: Out of the 180 cases analyzed, 90.7% of the recordings belonged to category II (Cat-2).A total of 43 babies had pH < 7.2, with 39 of them having a Cat-2 CTG.Baseline shift, bradycardia, and minimal variability were invariably associated with acidosis.Traces with late and prolonged decelerations had a higher occurrence of acidosis.Almost all the babies with poor APGAR score at 5 minutes had acidosis, with 30% of them going in for neonatal intensive care unit admission.It was seen that 100% of those recordings with Cat-3 had acidosis, whereas 29.5% of CTG-Cat-2 and 6.3% of the Cat-1 tracings had acidosis.Acidotic cord pH values were observed with longer second stages of labor and higher incidence of operative deliveries were noted in mothers with Cat-2 tracings. Conclusion:The presence of bradycardia, loss of beat-to-beat variability, and prolonged and late decelerations indicate a significant risk of acidosis.Therefore, CTG is an easy test that can help alert the obstetricians to implement necessary interventions when abnormal FHR patterns are detected.