Importance of Low Pregnancy Associated Plasma Protein-A (PAPP-A) Levels During the First Trimester as a Predicting Factor for Adverse Pregnancy Outcomes: A Prospective Cohort Study of 2636 Pregnant Women.

Abstract

The aim of this study is to investigate the predictive value of low levels of pregnancy associated plasma protein-A (PAPP-A) during the first trimester on adverse pregnancy outcomes, namely pregnancy induced hypertension (PIH), preeclampsia (PE), intrauterine growth restriction (IUGR), and fetal loss. This is a prospective cohort study including 2636 women with singleton pregnancies that attended the Prenatal Diagnosis Unit of the First Department of Obstetrics and Gynecology of National and Kapodistrian University of Athens in "Alexandra Hospital" between 2017 and 2019 for the first trimester combined screening routine scan. The study population was divided into two groups according to their PAPP-A levels. The cut-off value of the PAPP-A level was defined as the 0.4 multiple of median (MoM) which is in correspondence with the fifth centile. The women were followed-up prospectively until delivery and the primary outcome measures were the incidence of PIH, PE, IUGR (<10th centile), and fetal loss. Results: PAPP-A levels of ≤0.4 MoM were associated with increased maternal body mass index (BMI), increased uterine arteries pulsatility index (PI), and lower birth weight. Women with PAPP-A levels ≤0.4 MoM were more likely to develop PE (2.3% vs. 0.2%, p<0.001), PE or PIH (2.3% vs. 0.4%, p=0.003), IUGR (2.3% vs. 0.4%, p=0.003), and combined adverse outcome (25.5% vs. 1.9%, p<0.001) compared to women with PAPP-A>0.4 MoM. This study confirms that among women with PAPP-A levels ≤0.4 MoM in the first trimester, there are increased odds for PE or PIH, IUGR, and combined composite pregnancy outcome.