Prisca – Prenatal screening test

Manufacturer Siemens Healthcare Diagnostics

Why is prenatal screening performed?

Prenatal screening enables all pregnant women of any age and without any risk or pain, to find out more about the health of their unborn baby. The prenatal screening consists of a simple vein blood draw and a routine ultrasound examination at the gynecologist. Prenatal screening tests are a group of tests that give information to the doctor about the condition of the pregnant woman and her baby. These tests are quick, simple and highly specific with very high percentage of accuracy. It helps in identifying those pregnant women, out of the general population, who have an increased risk of delivering baby with defects.

What does PRISCA stand for?

PRISCA software (Prenatal RISk CAlculation software) includes measuring of specific markers that circulate in the blood of the mother and are directly related to the development and well-being of the fetus. The obtained values are combined along with other important parameters, such as: the age and health of the patient, as well as parameters of the fetus obtained by ultrasound (gynecological ultrasonography). Of no less importance is any other information gathered from the patient’s medical history, pregnancy, body weight, twin pregnancy, diabetes, and so on. After the software program calculates all the data, we get the final result, which indicates the risk of the fetus having one of the following abnormalities: Down syndrome, Edwards syndrome, and neural tube defect.

Down syndrome (trisomy 21) is a condition in which the fetus has excess genetic material, i.e. one more copy of the chromosome No. 21.This is the most common cause of mental retardation and it represents the most common chromosomal abnormality, which occurs with a frequency of 1 in 700-800 births. Although this syndrome is more common in women over 35 years of age, most babies with Down syndrome are born to mothers under 35 years. Infants with this disorder have a different physical appearance – broad face with slanted eyes, small ears with hearing impairment, short stature, mental retardation and often congenital heart defects, deformities of the gastrointestinal tract, etc.

Remember: positive screening test is not a final diagnosis; it just means that further more invasive tests are needed in order to determine whether your baby has any of the following conditions.

Which stage of pregnancy is best for conducting these tests for early detection of possible fetus defects?

The assessment of possible risks can be done very early, in the 10th to13th gestational week of the pregnancy. However, PRISCA can be performed up to the 22th week of the pregnancy.

What is the accuracy of the diagnostic procedures for detecting fetal abnormalities?

The percentage of detection of high-risk pregnancies, using this combination of laboratory marker-tests and ultrasound measures is up to 95%. However, a definitive confirmation is obtained only by invasive diagnostic procedures (amniocentesis or chorionic biopsy)

Is there a risk of causing unwanted abortion during the procedure?

Due to the fact that the entire procedure is safe, simple and inexpensive, prenatal screenings arerecommended for every pregnant woman*

(* Recommended by the American College of Obstetricians and Gynecologists, ACOG Practice Bulletin No. 77: Screening for Fetal Chromosomal Abnormalities. Obstetrics & Gynecology 2007; 109(1):217-228)