The prediction and prevention of intrapartum fetal asphyxia in preterm pregnancies

Abstract

Objective: This study was undertaken to examine the contribution of electronic fetal heart rate monitoring in the prediction and prevention of intrapartum fetal asphyxia in the preterm pregnancy. Study Design: The outcome of 40 pregnancies with biochemically confirmed intrapartum fetal asphyxia (ie, an umbilical artery base deficit >12 mmol/L) was examined. This included 20 pregnancies that were delivered abdominally matched with 20 pregnancies that were delivered vaginally. Antepartum and intrapartum clinical risk factors and newborn complications were documented. The interpretation of the fetal heart rate record as determined by the responsible clinicians was recorded. Fetal asphyxia was classified as mild, moderate, or severe on the basis of an umbilical artery base deficit of >12 mmol/L and newborn encephalopathy and other organ system complications. Results: Fetal asphyxia was classified as mild in 21 pregnancies and as moderate or severe in 19 pregnancies. The fetal heart rate record was predictive of fetal asphyxia in 27 pregnancies and nonpredictive in 11 pregnancies. The predictive fetal heart rate record was the primary indication for intervention in 21 of the 24 pregnancies that were delivered by cesarean delivery in the first stage or operative vaginal delivery in the second stage of labor. Newborn outcome may have been influenced by intervention and delivery because of a predictive fetal heart rate record in 10 pregnancies with mild fetal asphyxia and in 9 pregnancies with moderate or severe fetal asphyxia. Conclusion: Electronic fetal monitoring is a useful screening test for the prediction of intrapartum fetal asphyxia in the preterm pregnancy. A predictive fetal heart rate record was the principle indication that led to intervention and delivery. A prediction of fetal asphyxia that leads to intervention and delivery may prevent or modify moderate or severe newborn morbidity as the result of fetal asphyxia. (Am J Obstet Gynecol 2002;186:279-82.)