Foetal heart rate patterns in early labour in low and high risk pregnancies and its correlation with perinatal outcome.

The present prospective study included 173 randomly selected primigravidae at admission in early labour. Of these, 88 cases were of low risk and 85 cases were of high risk, on the basis of antenatal risk factors. All the cases were subjected to a twenty minutes recording of the foetal heart rate patterns and uterine contractions in early labour. It was interesting to note that, 13% of so called low risk pregnancies showed abnormal foetal heart pattern and thus became high risk in labour. No statistically significant difference was seen in the baseline heart rate and variability patterns in low and high risk pregnancies. However, all types of decelerations were more frequent in the high risk pregnancies. It was observed that as compared to baseline heart rate and variability, decelerations were better predictors of a poor perinatal outcome especially late decelerations and variable decelerations with ominous features, the mean Apgar scores at one minute of the two being 5.6 and 6.8 respectively.