Abnormal Antepartum Fetal Heart Rate in High Risk Pregnancies with Good Fetal Outcome

A consecutive study of 698 pregnant women for the incidence of abnormal fetal heart rate (FHR) in 2 groups of high risk pregnancy (HRP) with good outcome is presented. Group A consisted of 480 cases, with mild high risk pregnancies in whom a low rate of fetal distress was expected, and group B consisted of 218 cases, of a more severe type of high risk pregnancies in whom a higher rate of fetal distress was expected due to possible fetoplacental unit insult. Both groups combined had a 16.8% rate of pathological FHR. In group A the rate of pathological FHR was 12.3% whereas in group B it was 26.6%. This difference was statistically significant. The most common FHR pathology in group A was loss of variability (36.5%). In group B the most common pathology was FHR decelerations (37%). The demonstration of higher rates of abnormal FHR record in the more severe group of HRP, despite the fact that in all cases the outcome was good, may suggest that a pathological pattern even if sporadic, may represent an early sign of fetal distress which cannot be appreciated by using the conventional criteria of outcome in pregnancy.