title: A risk model approach to the prediction of fetal acidemia.
abstract: Known risk factors for adverse perinatal outcome were related to severe fetal acidemia during labor and at birth. Severe fetal acidemia was defined as a fetal scalp or umbilical artery pH > 3 SD below the mean for normal pregnancy. pH values were available for 1,524 singleton births without congenital anomalies. Of these births, 83 (5.4%) had at least one pH value > 3 SD below the reference mean. Known risk factors in the group with severe acidemia were compared with those in a random sample of the remaining 94.6% births. The strongest predictor of severe fetal acidemia was an abnormal cardiotocogram with a Hammacher score > 8. Risk factors shown to lower pH values significantly were combined in a prediction model based on multiple regression analysis. Back-validation of the model showed that half of all cases of severe fetal acidemia could not be adequately predicted. It is concluded that such prediction models do not contribute to a more effective detection of severe fetal acidemia.
authors.affiliation: Department of Obstetrics and Gynecology, Leiden University Medical Centre, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: Kianmanesh Rad
authors.forename: F P
authors.initials: FP
authors.lastname: Vandenbussche
authors.forename: S
authors.initials: S
authors.lastname: Le Cessie
authors.forename: D
authors.initials: D
authors.lastname: Oepkes
authors.forename: R G
authors.initials: RG
authors.lastname: Westendorp
authors.forename: M J
authors.initials: MJ
authors.lastname: Keirse
mesh_terms: D000138:Acidosis / Q000175:diagnosis*; D015148:Cardiotocography; D002585:Cesarean Section; D005189:False Positive Reactions; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D005865:Gestational Age; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007743:Labor, Obstetric / Q000502:physiology; D011247:Pregnancy; D012372:ROC Curve; D012044:Regression Analysis; D012307:Risk Factors; D012535:Scalp / Q000098:blood supply / Q000196:embryology; D014469:Umbilical Arteries