Study of fetal heart rate abnormalities observed on cardiotocography in Lubumbashi: about a cases followed at the Lubumbashi University Clinic and the General Hospital of the Cinquantenaire

Cardiotocography (CTG) has recently come into use in Lubumbashi but no thorough study has yet been conducted to identify its impact on perinatal morbi-mortality. This study aims to determine the frequency of fetal heart rate abnormalities (FHR)in order to identify the associated factors and to propose a suitable management. We conducted a cross-sectional, descriptive study of 411 women in labour over a period of 19 months (March 2015-December 2016). In patients with pathologic FHR abnormalities, sensitivity and positive predictive value of cardiotocography in the screening test for acute fetal distress were 82.95% and 45.35% respectively. FHR abnormalities were found in two women in labour out of five. Decelerations were the most frequent FHR abnormalities observed (50.8%) with a remarkable predominance of late decelerations (22.1% of all abnormalities). The factors associated with pathological FHR abnormalities were prolonged labor (OR = 14.64, CI = 3.91-54.81), chorioamnionitis (OR = 14.56, CI = 3.83-55.34), chronic maternal anemia (OR = 4.99, CI = 1.48-16.85), primiparity (OR = 2.69, CI = 1.49-4.85), prematurity (OR = 2.90, CI = 1.51-5.54) and prolonged pregnancy (OR = 3.22, CI = 1.38-7.52). Intrauterine growth retardation and arterial hypertension were mainly associated with flat lines and late decelerations (OR = 7.79, CI = 2.50-24.30 and OR=2.74, CI = 1.31-5.72). CTG is a screening tool for the identification of acute fetal distress but with high false-positive rate (55%); it should be associated with other second-line screening tests for acute fetal distress in order to reduce this rate. Factors associated with pathologic FHR abnormalities often cause acute fetal distress thus requiring a rigorous analysis of CTG traces.