Comparing first trimester screening performance: routine care gynaecologists' practices vs. prenatal centre.

Area of Science:

• Prenatal Diagnostics
• Maternal-Fetal Medicine
• Genetics

Background:

• First-trimester screening for fetal trisomy 21 is crucial for early detection.
• Comparing screening performance between general gynaecologists' practices and specialized prenatal care centers is important for healthcare quality.

Purpose of the Study:

• To evaluate and compare the screening performance for fetal trisomy 21 in the first trimester.
• To assess screening effectiveness in general gynaecologists' practices versus specialized prenatal care centers in Germany.

Main Methods:

• Included 15,026 serum samples analyzed for free beta-human chorionic gonadotropin (hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11-14 weeks gestation.
• Fetal risk for trisomy 21 calculated using nuchal translucency (NT) and crown-rump-length (CRL), with measurements from general practices or a tertiary prenatal center.
• Detection rates calculated for a fixed risk cut-off (1:300) and false-positive rate (5%) using NT, serum biochemistry, maternal age, and combinations thereof.

Main Results:

• The combined screening (maternal age, NT, free beta-hCG, PAPP-A) achieved detection rates of 78.9% in general practices and 88.5% in specialized centers for a 5% false-positive rate.
• Screening performance varied depending on the method used, with combined screening demonstrating superior detection rates.
• Risk estimation for trisomy 21 was higher in pregnancies with the condition (78.9-88.5%) compared to normal pregnancies (5.1-8%).

Conclusions:

• First-trimester screening for fetal trisomy 21 yields satisfactory results in both general gynaecologists' practices and specialized prenatal centers.
• The combined screening approach offers the highest detection rates for fetal Down syndrome.
• Standardized protocols and training may further enhance screening performance across different practice settings.