1170. Package # 24 Prenatal screening I trimester (PAPP-A, free β-HCG)

Package No. 24 – first trimester biochemical screening. Includes PAPP-A and free β-hCG determination to assess the risk of fetal chromosomal abnormalities (21, 18, 13). Recommended for weeks 11–13 as part of combined screening.

Package No. 24 (First Trimester Prenatal Screening: PAPP-A, Free β-hCG) is a non-invasive laboratory test included in the first trimester prenatal biochemical screening.

The package includes two key markers:

• PAPP-A – pregnancy-associated protein;
• Free β-hCG – free beta-subunit of human chorionic gonadotropin.

These indicators is aimed at:

• assessing the risk of fetal chromosomal abnormalities (trisomy 21 – Down syndrome, trisomy 18 – Edwards syndrome, trisomy 13 – Patau syndrome);
• to suspect placentation abnormalities (risk of preeclampsia, IUGR).

In combination with ultrasound parameters (CRL, nuchal translucency thickness, nasal bone thickness), these data are used for an individualized risk calculation using PRISCA software. Package No. 24 (First Trimester Prenatal Screening: PAPP-A, Free β-hCG) does not include ultrasound data or take into account the pregnant woman's personal information, so this calculation has lower diagnostic sensitivity compared to the full combined screening.

PAPP-A and β-hCG levels vary depending on gestational age, so it is important to have the test performed between 11 weeks 0 days and 13 weeks 6 days, in accordance with the due date determined by ultrasound.

Package No. 24 is recommended for pregnant women in the first trimester of pregnancy to assess levels of PAPP-A and free β-hCG markers, which are associated with the risk of trisomies 21, 18, and 13.

Recommended timing: from 11 weeks 0 days to 13 weeks 6 days of pregnancy, based on ultrasound results.

The study does not include an individual risk calculation and does not take into account ultrasound parameters or personal patient characteristics. The indicators are interpreted without calculating the combined risk using software (PRISCA), and therefore may be less informative than with full combined screening.

This package is recommended for use:

• if an ultrasound has not yet been performed;
• for a preliminary preliminary assessment;
• if rapid baseline testing is needed;
• as part of a more comprehensive approach to fetal monitoring.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: