MIDTRIMESTER N-TERMINAL PROATRIAL NATRIURETIC PEPTIDE, FREE BETA-HCG,AND ALPHA-FETOPROTEIN IN PREDICTING PREECLAMPSIA

Objective: To determine whether maternal midtrimester serum N-terminal peptide of proatrial natriuretic peptide, free beta subunit of human chorionic gonadotropin (hCG beta), or alpha-fetoprotein (AFP) levels c an predict preeclampsia.Methods: A population-based cohort included 10 37 nulliparous women, of whom 637 (61%) participated in a maternal ser um Down syndrome screening program. Measurements of hCG beta, AFP, and N-terminal peptide of proatrial natriuretic peptide were made from ma ternal serum collected at 15-19 weeks' gestation. Sensitivity, specifi city, and predictive values were calculated for elevated AFF (at least 2.0 multiples of the median [MoM]) and hCG beta (at least 2.0 MoM) va lues. Results: No difference was found in the concentrations of the N- terminal peptide of proatrial natriuretic peptide among the 30 women i n whom preeclampsia developed later (median 270 [range 142-604] pmol/L ) compared with 536 women who remained normotensive (274 [51-2626] pmo l/L). The sensitivity and specificity of elevated AFP in predicting pr eeclampsia were 3% and 98% and those of elevated hCG beta were 20% and 84%, respectively. When a stepwise multiple logistic regression model was used, only mean arterial pressure was an independent risk factor in predicting preeclampsia. Conclusion: Determinations of the proposed new marker N-terminal peptide of proatrial natriuretic peptide, as we ll as serum hCG beta or AFF, are not helpful in predicting preeclampsi a. (C) 1998 by The American College of Obstetricians and Gynecologists .