First-trimester serum PAPP-A and fβ-hCG concentrations and other maternal characteristics to establish logistic regression-based predictive rules for adverse pregnancy outcome

To determine the clinical relevance of maternal characteristics and first-trimester serum concentrations of pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotrophin (fβ-hCG) in predicting placenta-related complications, miscarriage and preterm delivery. DESIGN, SETTING AND POPULATION: A historical cohort study of data of the National Institute for Public Health and the Environment of first-trimester screening tests performed between July 2002 and May 2006 was done. Data from 28 566 (64.1%) tests were eligible for analysis. By logistic regression, predictive rules were made based on PAPP-A and fβ-hCG concentrations, maternal smoking, maternal weight and age, low birth weight, stillbirth and hypertensive disorders, miscarriage and preterm birth. Predictive values were analysed with the area under the curve (AUC) of receiver operating curves (ROC). Predictive for placenta-related complications were low PAPP-A, low fβ-hCG, smoking and weight (AUC 54%). For miscarriage low PAPP-A, low fβ-hCG and maternal age (MA) were predictive (AUC 78%) and for preterm delivery low PAPP-A, smoking, MA and maternal weight (AUC 55%). Only the predictive model for miscarriage had a clinically relevant predictive value of 28%. Results together do not justify closer surveillance of chromosomally normal pregnancies with PAPP-A or fβ-hCG levels below the fifth percentile