Abstract
Background: Fetal cardiac monitoring indications during labor and near delivery in high- and low-risk pregnancies and their effects on neonatal outcomes have been investigated in previous studies; however, the data of nonreassuring cardiotocography (CTG) near delivery on neonates are insufficient. Objectives: This study aimed to compare fetal distress with nonreassuring CTG in high- and low-risk pregnancies to see if high-risk pregnancies need different or more care or not. Methods: This retrospective cohort study was conducted on pregnant women candidates for vaginal delivery in an academic hospital within 2017 - 2020. The participants were divided according to maternal and fetal risk factors into two groups of low-risk and high-risk pregnancies (including preeclampsia/eclampsia, diabetes, placenta abruption, and intrauterine growth restriction). Three obstetricians, blinded to the participants and neonatal outcomes, reviewed the CTG tracing near delivery individually. The features of nonreassuring CTG 30 minutes before delivery, including variable deceleration, late deceleration, slow return to base, tachycardia, and shoulder and overshoot patterns, were detected in the traces. Then, the neonatal outcomes, including umbilical artery pH at birth, Apgar scores at the 1st and 5th minutes, and admission to the neonatal intensive care unit (NICU), were compared between the groups. Results: A total of 622 participants, including 322 high-risk and 300 low-risk pregnancies, with nonreassuring CTG, were recruited into the study. The adverse neonatal outcomes, such as NICU admission, low Apgar scores in the 1st and the 5th minutes, and pH < 7.1, were significantly different between high-risk and low-risk pregnancies with variable deceleration, tachycardia, and overshoot patterns. High- and low-risk pregnancies with late deceleration had only significantly different Apgar scores in the 5th minute. In the slow return to base features, the Apgar scores in the 1st and 5th minutes and NICU admission were significantly different in high- and low-risk groups. Additionally, NICU admission and low Apgar score in the 1st minute were higher in high-risk women in shoulder patterns. Conclusions: Nonreassuring CTG near delivery might be accompanied by more fetal distress in high-risk pregnancies. Therefore, the nonreassuring features of CTG in high-risk pregnancies should be considered more important and might need prompt and timely action to decrease the adverse outcomes.