Short-term variability assessment from abdominal electrocardiogram during the antepartum period.

One hundred eighty-eight patients undergoing antepartum fetal heart rate (FHR) monitoring with abdominal fetal electrocardiogram (ECG) technique were studied with respect to FHR variability derived from fetal R-R intervals. Statistically significant positive correlation existed between various measures of FHR variability and accelerations per minute (p less than 0.01). Insufficient numbers of positive contraction stress tests (CST) were available to establish a relationship with variability, although a trend existed between positive CST and low variability. Postdate pregnancies had significantly higher variability than nonpostdate pregnancies (p less than .05). This mathematical analysis establishes statistical significance between short-term variability and accelerations per minute and application of this technique for assessment of true variability in antepartum testing is possible.