Association of CTG Diagnosis of Intrapartum Fetal Distress and Immediate Postpartum Acidemia in Foetal Umbilical Artery.

BACKGROUND: Intrapartum fetal hypoxia which is one of the leading causes of neonatal morbidity and mortality is a preventable cause. Over the past years, many methods have been employed to diagnose fetal distress, a sign of fetal hypoxia, among these, cardiotocography (CTG) is the most widely used method. Diagnosis of fetal distress based on CTG can have high inter and intraobserver variation leading to either delayed or inessential intervention henceforth increasing maternal morbidity and mortality. Fetal cord arterial blood pH is an objective method to diagnose intrapartum fetal hypoxia, hence by observing the incidence of acidemia in cord blood pH among those newborns born through cesarean section (CS) in view of non-reassuring CTG can help make a judicious decision.

METHODS: In this single institutional observational study, patients admitted for safe confinement were subjected to CTG in the latent and active phases of labor. Non-Reassuring traces were further classified based on NICE guideline CG190. The cord blood of these neonates born through CS in view of non-reassuring CTG was drawn and sent for ABG analysis.

RESULTS: Among the 87 neonates delivered through CS in view of fetal distress, 19.5% had acidosis. Among those with pathological traces, 16(28.6%) had acidosis and one (100%) which was categorized as the need for urgent intervention showed acidosis. This result showed a statistically significant association ( p value-0.003). No statistically significant association was obtained when variation in baseline characters of CTG when taken independently.

CONCLUSIONS: In our study, neonatal acidemia which is the objective evidence of fetal distress was seen in 19.5% of our study population who underwent cesarean in view of non-reassuring CTG. Among these, acidemia was significantly associated with pathological CTG trace compared to suspicious trace. We also observed that abnormal FHR features when taken independently showed no significant association with acidosis. Acidosis among newborns certainly increased the requirement for active resuscitation and additional hospital stay. Hence, we conclude that by recognizing specific fetal heart rate patterns associated with acidosis in a fetus, a more judicious decision can be made, thereby preventing both delayed as well as inessential intervention.