The relationship between Apgar score, umbilical artery pH and operative delivery for fetal distress in 2778 infants born at term

Abstract

A total of 2778 infants born at term were studied to determine the relationship between Apgar scores after 1 min, umbilical artery pH values, mode of delivery, a diagnosis of fetal distress leading to operative delivery, and sex. Eighty-three percent of the population had normal Apgar scores (≥8) and normal pH values (>7.15) in which 10% were operatively delivered for fetal distress (ODFD). Sixty-one percent of the children with low Apgar scores (≤7) had normal pH values, and 74% of the infants with acidosis (pH ≤ 7.15) had normal Apgar score. Twenty-four percent of the infants with a low Apgar score and/or acidosis were ODFD (sensitivity). Ninety percent of the infants who had normal Apgar scores and pH values were not ODFD (specificity). The predictive value (a low Apgar score and/or acidosis) of ODFD was 33%, and the negative predictive value (normal Apgar score and a normal pH) of ODFD was 85%. A significantly higher incidence of ODFD and acidosis was found in boys.