Limitations in the clinical prediction of intrapartum fetal asphyxia

OBJECTIVE: Our purpose was to demonstrate the predictive value of clinical risk scoring and fetal assessment for intrapartum fetal asphyxia. STUDY DESIGN: Intrapartum fetal asphyxia was defined by an umbilical artery buffer base <34 mmol/L. The predictive value of 20 antepartum and intrapartum risk factors was examined in 1909 consecutive pregnancies. The predictive value of clinical risk factors with periodic fetal assessment was examined in a second population of 100 consecutive pregnancies with biochemically determined intrapartum fetal asphyxia. RESULTS: The incidence of intrapartum was 2.3%. Two problems were apparent in these studies. A significant proportion of intrapartum fetal asphyxia occurred in pregnancies with no risk factors. The positive predictive value of clinical risk factors was low, 3%, resulting in a large number of false positives requiring clarification. CONCLUSION: Screening and fetal assessment methods must be improved to ensure the early recognition of intrapartum fetal asphyxia that may require intervention during labor to avoid morbidity and mortality.