Introduction: Early identification of obstetric complications is critical for optimized management. We aimed to assess screening performance for common adverse outcomes using first and second trimester serum markers and maternal characteristics.
Methods: This was a retrospective case-control study including women who had multiple analytes screening for trisomy 21 and delivered at a single center from January 2014 to October 2017. Women with gestational hypertension (GH), preeclampsia (PE) and preterm birth (PTB) were considered cases. Three controls were assigned for each case. Serum levels of Pregnancy-Associated Plasma Protein A (PAPP-A), Placental Growth Factor (PlGF), free β-hCG, inhibin A and Alpha-Fetoprotein (AFP) were directly measured or obtained from routine screening records. The Multiple of the Median (MoM) values were compared between cases and controls. Multivariate analysis was performed to eliminate confounding factors.
Results: A total of 625 cases and 2012 controls were included. In the first trimester screening (FTS), cases of PE or GH presented significantly lower levels of PAPP-A, PlGF and free β-hCG, and higher AFP, compared to controls. In the second trimester screening (STS), both PE and GH cases presented lower PlGF, while PAPP-A was lower for PE cases only. PTB cases presented lower PAPP-A in FTS and lower PlGF and higher AFP in both FTS and STS (Table 1). Screening performance for PE, combining analytes and maternal characteristics was superior at the FTS in comparison to STS, with better prediction of early onset PE (Table 2). Low detection rate for all outcomes with a 10% false positive rate (FPR) improved when a 20% FPR was adopted (54% for PE, 71% for early PE, 40% for GH and 44% for PTB).
Conclusion: Maternal biochemical markers are abnormal in first and second trimester of pregnancies complicated by hypertensive disorders or PTB. Screening performance is moderate for early onset PE but poor for GH and PTB.
Tianhua Huang– Associate Professor, North York General Hospital
Melanie Bedford– Medical Genetics Specialist, North York General Hospital
Amir Aviram– MFM Specialist, Sunnybrook Health Sciences Centre
Sara Jones– Medical student, University of Toronto
Stefania Ronzoni– MFM Specialist, Division of maternal fetal medicine, Department of Obstetrics and Gynecology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
Elad Mei-Dan– MFM Specialist, North York General Hospital