Role of ST-Analysis of Fetal ECG in Intrapartal Fetus Monitoring with Presumed Growth Retardation

Overview

Objective:
Evaluation of the role of ST analysis of fetus ECG for early detection of developing acute hypoxia in the course of delivery of fetuses with presumed growth retardation. A comparison with present way of intrapartal fetus monitoring. Impact on the number of surgical births for indications of threatening fetus hypoxia. Influence of the method on perinatal results and postnatal adaptation of the newborns.

Type of study:
A prospective study.

Setting:
Gynecology – Obstetrics Clinic, Masaryk University and Teaching Hospital Brno.

Method:
Forty seven women with a growth retardation of the fetus diagnosed before delivery who gave birth in the Teaching Hospital in Brno during 2003 – 2005 and intrapartal ST analysis of fetus ECG was subsequently used, were enrolled into this prospective study (group A). The control group consisted of 87 deliveries taking place in the same period of time and concerning women with fetuses suffering from growth retardation and monitored by standard methods (group B). The standard methods included cardiotocography (CTG), supplemented with pulse oximetry (IFPO) if needed. The diagnosis of intrauterine fetus growth retardation was established on the basis of the results of repeated prepartal ultrasound fetus biometry with estimation of the mass, which corresponded to a group below 10 percentile for the given gestational age. The numbers of vaginal deliveries and surgically treated delivery due to threatening fetus hypoxia (Cesarean section, forceps delivery) were recorded. The authors evaluated postpartal pH from umbilical artery, independently for the group of values of pH < 7.00, the group of pH 7.00 – 0.10 and pH 7.10 or more. The values of Apgar score were evaluated for the first, fifth and tenth minute, respectively. The neonatologist followed the duration of stay of the newborn at the Newborn Intensive Care Unit, the Intermediate Care Unit, total duration of hospitalization, the occurrence of sepsis in the early newbotn period, the occurrence of hyperbilirubinemia, and the conclusion of neurological examination. All the results were evaluated statistically by the χ² test, Kruskal – Wallis test or the Anova method.

Results:
There was no statistically significantly difference in the number of delivery ended by surgery for threatening fetus hypoxia (p = 0.856) or the detection rate of intrapartal hypoxia according to pH values of umbilical blood divided into the three groups (p = 0.657, p = 0.958, p = 0.730, respectively). The values of Apgar score differed in favor of the group A significantly only in the first minute at the level of 5% opf significance (p = 0.018). The values of Apgar score in the fifth and tenth minute did not show any significant difference (P = 0.301 and p = 0.313, respectively). There was no statistically significant difference in neonatological results between the group A and B.

Conclusion:
The use of ST analysis of fetal ECG in the course of delivery of fetuses with presumed intrauterine growth retardation did not show any significant difference from the presently used methods (CTG supplemented with IFPO if needed). In using the method there was not any effect on the number of surgically treated deliveries for indications of threatening acute fetus hypoxia or perinatal results and postnatal adaptation of the newborns.

Key words:
cardiotocography, fetal pulse oximetry, ST analysis of fetal ECG, fetus hypoxia