Intrapartum electronic fetal monitoring and perinatal outcomes: Analysis of components of fetal heart rate pattern

Abstract

Aim: The aim of this study was to assess the components of cardiotocography (CTG) during labor to identify the variables associated with the risk of adverse perinatal outcomes and to ascertain the mode of delivery in these women. Materials and Methods: This prospective observational study included 191 women at term with singleton pregnancy in labor. The CTG findings including baseline heart rate, accelerations, beat-to-beat variability, and type and severity of decelerations were noted as per the International Federation of Gynecology and Obstetrics classification and grouped into Category II or III patterns as per the National Institute of Child Health and Human Development classification. Low APGAR score, cord PH <7, neonatal intensive care unit admission, respiratory distress, and hypoxic-ischemic encephalopathy were considered adverse neonatal outcomes. Results: Persistent fetal tachycardia, poor beat-to-beat variability, and severe variable deceleration showed a significant association with adverse neonatal outcome and delivery by cesarean section (P < 0.05). Adverse neonatal outcomes were noted in 4.2% of babies and 40.9% of babies born to mothers whose CTG was categorized as II and III patterns, respectively (P < 0.001). Birth by cesarean section was significantly different between those with Category II and Category III patterns, 33.7% and 65.4%, respectively (P < 0.01). Conclusion: Reduction in the beat-to-beat variability and presence of severe variable decelerations are independent risks for adverse neonatal outcomes, irrespective of the category of CTG pattern. Category III fetal heart rate pattern shows a significant association with adverse outcomes and risk of cesarean delivery. Grading the Category II patterns may help in identifying variables that are truly associated with acidemia and further research into this is recommended.