Association of electronic fetal monitoring during labor with cesarean section rate and with neonatal morbidity and mortality

Data from the 1980 National Natality Survey by the National Center for Health Statistics were used to assess the relation of electronic fetal monitoring (EFM) during labor with cesarean section rates and neonatal morbidity and mortality. In univariate analyses, EFM was associated with higher cesarean section rates, lower five-minute Apgar scores, and a higher rate of respiratory distress. Logistic regression analysis controlling for other risk factors for poor neonatal outcome indicated that the association of EFM with higher cesarean section rates persisted (odds ratio 1.45, 95% CI 1.16, 1.81), except in certain pregnancies at very high risk for cesarean section. EFM was associated with an Apgar score less than 6 at five minutes only if delivery was by cesarean section. EFM was not found to be independently associated with respiratory distress. Neither univariate nor multivariate analyses found an association of EFM with neonatal mortality. These results suggest that EFM may identify hypoxic infants, who are frequently delivered by cesarean section. The lack of association of EFM with beneficial neonatal outcomes is consistent either with lack of effect of EFM or with uncontrolled selection bias.