Auscultation of foetal heart rate: an assessment of its error and significance.

AUSCULTATION OF FOETAL HEART RATE WAS SHOWN TO BE SUBJECT TO THREE TYPES OF ERROR: a random error, an error biased towards normality when the heart rate is fast or slow, and an error based on the inability to count the heart rate during contractions. In spite of these limitations a clinically observed foetal heart rate of more than 160 beats per minute was shown to be associated with significantly lower Apgar scores at birth. In contrast, a steady foetal heart rate of 100-120 beats per minute was not.