First-Trimester Preterm Preeclampsia Screening in Nulliparous Women: The Great Obstetrical Syndrome (GOS) Study

To estimate the ability of a combination of first-trimester markers to predict preterm preeclampsia in nulliparous women. We conducted a prospective cohort study of nulliparous women with singleton gestations, recruited between 110 and 136 weeks gestation. Data on the following were collected: maternal age; ethnicity; chronic diseases; use of fertility treatment; body mass index; mean arterial blood pressure (MAP); serum levels of pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), alpha fetoprotein (AFP), free beta human chorionic gonadotropin (ß-hCG); and mean uterine artery pulsatility index (UtA-PI). We constructed a proportional hazard model for the prediction of preterm preeclampsia selected based on the Akaike information criterion. A receiver operating characteristic curve was created with the predicted risk from the final model. Our primary outcome was preterm preeclampsia and our secondary outcome was a composite of preeclampsia, small for gestational age, intrauterine death, and preterm birth. Among 4659 nulliparous women with singleton gestations, our final model included 4 variables: MAP MoM, log10PlGF MoM, log10AFP MoM and log10UtA-PI MoM. We obtained an area under the curve of 0.84 (95% CI 0.75–0.93) with a detection rate of preterm preeclampsia of 55% (95% CI 37%–73%) and a false-positive rate of 10%. Using a risk cut-off with a false-positive rate of 10%, the positive predictive value for our composite outcome was 33% (95% CI 29%–37%). The combination of MAP, maternal serum PlGF and AFP, and UtA-PI are useful to identify nulliparous women at high risk of preterm preeclampsia but also at high risk of other great obstetrical syndromes. Estimer la capacité d'une combinaison de marqueurs du premier trimestre à prédire la pré-éclampsie avant terme chez les femmes nullipares. Nous avons mené une étude de cohorte prospective de grossesses monofœtales chez des femmes nullipares recrutées entre 11 SA +0 j et 13 SA + 6 j. Les données suivantes ont été recueillies : âge maternel; origine ethnique; maladies chroniques; traitement de l'infertilité; indice de masse corporelle; pression artérielle moyenne; taux sériques de protéine A plasmatique associée à la grossesse (PAPP-A), facteur de croissance placentaire (PlGF), forme soluble du récepteur au VEGF de type 1 (sFlt-1), alphafœtoprotéine (AFP), bêta-hCG libre (ß-hCG); et indice de pulsatilité moyen de l'artère utérine. Nous avon