Monitoring Intrapartum Fetal Distress by Cardiotocography & Observe its Relation with Umbilical Cord Blood Sampling & Perinatal Outcome

Abstract

Background: Cardiotocography (CTG) being a simple noninvasive tool has been used more frequently in recent decades to detect fetal distress & to reduce neonatal mortality &morbidity related to fetal hypoxia. On the other hand, umbilical cord blood gas can be used to detect fetal acidaemia due to fetal distress more accurately. This study aimed to correlate fetal monitoring findings by intrapartum CTG with umbilical cord blood pH & lactate level &test the ability of CTG to predict fetal distress & neonatal outcome. Materials and Methods: This prospective cross-sectional observational study was conducted in the Department of Obstetrics and Gynecology of Chittagong Medical College Hospital, Chattogram, Bangladesh for one year from July 2020 to June 2021. It included 80 term singleton pregnancies in active labour. Intrapartum CTG was taken and classified into normal, suspicious and pathological according to FIGO guidelines of CTG monitoring 2015. Mode of delivery, liquor colour, Apgar scores at 1 and 5 minutes, and admission to the neonatal intensive care unit (NICU), adverse neonatal outcomes were observed. Immediately after delivery of the baby 10 cm of the umbilical cord was clamped doubly and 2-3 ml of umbilical cord arterial blood was taken immediately in a pre-heparinized syringe and sent to a laboratory for assessment of pH and lactate to detect fetal acidosis. Antenatal CTG was correlated to neonatal outcomes and cord blood acidosis by statistical analysis. Results: In this study, 40.0% of the women had normal CTG, 38.8% had suspicious CTG, and 21.2% had pathological CTG. There was a significant worsening of neonatal outcomes across these three groups concerning depressed (<7) Apgar scores at 1 minute (40.6%, 80.6%, and 100%; P<0.001), depressed Apgar scores at 5 minutes (3.1%, 22.6%, and 47.1%; P<0.001), and admission to the NICU (9.4%, 38.6%, and 70.7%; P<0.001). When CTG was pathological or suspicious CTG delivery by LSCS was 5.33 times higher (RR: 5.33; 95% CI: 2.09 -13.63) compared to subjects with normal CTG. There was also a progressive worsening of cord blood pH (7.25±0.05, 7.20±0.06, and 7.13±0.09; P<0.001) and a progressive increase in lactate (3.66±1.01 mmol/l, 4.79±1.61 mmol/l, and 6.63±2.18 mmol/l; P<0.001). Conclusions: It should be concluded that pathological CTG which correlates intrapartum fetal hypoxia with cord blood acidaemia and adverse neonatal outcomes. As cardiotocography is a simple, cost-effective noninvasive tool it can be used to detect fetal distress in labour. Continues CTG monitoring can be offered or recommended in every labour room setting to detect fetal distress & early intervention to prevent neonatal morbidity & mortality.