COMPARISON OF THE T/QRS RATIO OF THE FETAL ELECTROCARDIOGRAM AND THE FETAL HEART-RATE DURING LABOR AND THE RELATION OF THESE VARIABLES TO CONDITION AT DELIVERY

The T/QRS ratio of the fetal electrocardiogram (ECG) was recorded to within 30 min of delivery from 105 women in labour. There were no significant differences in the mean T/QRS ratio in the last hour of record between those with normal and intermediate, or abnormal fetal heart rate (FHR) patterns. In 66 labours the mean T/QRS ratio in the first hour of record was compared with that of the last hour; the only significant change was a small decrease in the mean ratio from 11% to 7% in a group of 11 fetuses with an abnormal FHR pattern throughout the recording time. Eight babies were born with evidence of acidosis (umbilical artery pH less-than-or-equal-to 7.16), and another four were born in poor condition (1 min Apgar score < 4) without evidence of acidosis; none had a mean last hour T/QRS ratio significantly different from the previously established normal range.