Correlation of cardiotocographic parameters witt the risk of neonatal hypoxic ischemic encephalopathy

Objective. To determine cardiotocographic (CTG) criteria for the risk of hypoxic ischemic encephalopathy (HIE) varying in severity. Subjects and methods. The prospective case-control study included 180 female patients and their newborn infants. After the birth of a baby, the CTG curves were interpreted by a specialist. Results. A pathological CTG curve was predominant in the study patient group (66.7% vs. 16%; p < 0.0001); a suspicious CTG curve was prevalent in the control group (48.6% vs. 16.7%; p < 0.001). A detailed analysis of CTG data showed the higher frequency of late decelerations in the study group (p <0.001); the presence of variable decelerations did not lead to the emergence of HIE. Bradycardia below 100 beats increased the risk of HIE (p < 0.001). Tachysystole was diagnosed significantly more often in the study patient group (44.4% vs. 12.5%, p < 0.001). No relationship was found between the type of a CTG curve and the grade of neonatal HIE. There were 10(4-14.25), 7(1.75-25.25), and 45(38-52) decelerations in grades 1, 2, and 3 HIE, respectively (p = 0.02). The duration of a CTG curve with decelerations was 36.1 (20.4), 40.8 (24.9), and 59.0 (32.5) min, respectively (p = 0.05). The severity of HIE increased with a larger number of late decelerations (p = 0.03). Conclusion. This paper shows the relationship between the CTG curve parameters and the risk of neonatal HIE. The risk factors for the development of HIE are a pathological type of CTG; a decrease in basal heart rate and variability; late decelerations; bradycardia, and tachysystole. The clinical manifestations of neonatal encephalopathy with a normal or suspicious type of CTG in childbirth may suggest that there are causes of HIE, which are unassociated with intranatal fetal hypoxia.

hypoxic ischemic encephalopathy, cardiotocography, fetal hypoxia