Electronic fetal monitoring during labor.

Intrapartum electronic fetal monitoring tracings from 620 women monitored internally over 60 minutes were analyzed. Fetal heart rate patterns were statistically analyzed against four variables of labor: 1) the presence of meconium; 2) fetal acidosis; 3) 1-minute Apgar score; and 4) clinical correlates considered as etiologic factors in FHR decelerations. No significant etiologic correlation was found between these clinical correlates and FHR deceleration patterns. Statistically significant correlations were established between poor neonatal outcome and fetal acidosis (P less than 0.01) and the presence of meconium (P less than 0.05). No correlation was found between FHR patterns and fetal acidosis. Variable deceleration showed no significant relation to low Apgar score (less than or equal to 6). Late deceleration showed a significant correlation with depressed infants. FHR patterns are best used as an alarm system of fetal difficulty than as an absolute measure of fetal distress.