Altered PAPP-A and Placental Thickness in Pre-Eclampsia and Intrauterine Growth Restriction: A Pilot Study

Abstract

Pre-eclampsia (PE) is a multisystem disorder that affects 5–6% of all pregnancies. Background: PE and intrauterine growth restriction (IUGR) are two major causes of maternal mortality and morbidity. We hypothesize that first-trimester pregnancy-associated plasma protein-A (PAPP-A) levels are useful as a prognostic marker. The aim of our study is to identify the role of PAPP-A and placental thickness in pre-eclampsia screening, as well as its value in IUGR prognosis. Methods: This prospective study was conducted at the Al. Simionescu County Hospital Hunedoara, Romania, Department of Obstetrics and Gynecology, from 12 May to 31 October 2025. A total of 102 patients were included in our study; of these, 28 patients (28.56%) developed pre-eclampsia, and 13 (13.26%) developed IUGR associated with PE. Results: The demographic data showed no differences between groups, except for BMI, smoking habits, and diabetes mellitus. Of the 28 cases of pre-eclampsia, 14.28% had PE detected by 28 weeks, 46.4% had PE associated with IUGR by 33/34 weeks, and 39.32% had PE detected at term/delivery. The highest detection rate was at 33/34 weeks, when the association with IUGR was obvious. For PE with IUGR at 34 weeks, the area under the curve (AUC) was 0.909, with a p-value < 0.001. The PAPP-A cut-off was 0.65 MoM, indicating high sensitivity and specificity for predicting PE. Placental thickness was also assessed, resulting in statistically significant differences between groups. The PAPP-A level shows strong predictive value for PE, especially when associated with placental thickness. Conclusions: This study demonstrates a clear correlation between low PAPP-A in the first trimester of pregnancy, placental thickness in the second trimester, and the subsequent development of pre-eclampsia and its association with IUGR.