Prenatal screening test

Prenatal screening test

HARMONY PRENATAL DIAGNOSTIC TEST
Non-invasive prenatal testing for the diagnosis of the most common fetal trisomies and fetal aneuploidy of the X and Y chromosomes, simple safe and without risk to the mother and fetus.

What is Harmony Prenatal Test

It' a non-invasive prenatal diagnostic test that can detect accurately , the most common fetal trisomies , trisomy 21 , or Down syndrome , trisomy 18 or Edwards Syndrome , Trisomy 13 or Patau syndrome , aneuploidy of the X and Y chromosomes ( Turner syndrome , Klinefelter , XYY ) and fetal sex from the 10th week of pregnancy until the end .

It’s a safe examination and presents no danger to the mother and fetus as it runs on a simple aspiration of the maternal blood.

How does Harmony Prenatal Test

The test is a combination of the latest scientific findings in the field of prenatal diagnosis and innovative molecular biology technologies.
Numerous scientific studies have demonstrated the presence of fetal DNA in maternal blood during the entire pregnancy.
The total DNA (fetal and maternal) is extracted from the blood , is then identified that of the fetus that is distinct from that of the mother because it is in the form of small fragments. Sequentially and analyze markers that identify fetal chromosomes 13, 18, 21, X and Y by direct analysis of fetal DNA itself. This allows to investigate if there is an extra copy of the chromosome analyzed.

How accurate Harmony Prenatal Test

The test has a 99% higher diagnostic reliability for trisomy 21 with a lower rate of false positives to 0.1%
The data relating to the accuracy of diagnostic Harmony Prenatal Test are reported in the table.

  Rate of diagnosis False positive rate
TRISOMY 21
>99%
<0,1%
TRISOMY 18
>98%
<0,1%
TRISOMY 13
80%
<0,1%
The X and Y chromosomes test provides greater accuracy of 99 % in the determination of the sex of the fetus. The test determines the risk of aneuploidy of the X and Y chromosomes

The prenatal tests compared: benefits and limitations

The tests of prenatal screening in the first trimester of pregnancy, such as the measurement of nuchal translucency combined with the two biochemical markers, free-βHCG and PAPP-A, are non-invasive prenatal testing, but have a false positive rate of up to 5% and They do not detect correctly up to 30% of cases of trisomy 21.

These tests can, in fact, bring a positive for fetal trisomy although in fact we are in the presence of a pregnancy with a healthy fetus (false positive) or may bring a negative for fetal trisomy, while in reality we are dealing with pregnancy a fetus with fetal trisomy (false negative).

The prenatal diagnostic tests, such as amniocentesis and chorionic villus sampling, while having a diagnostic reliability of over 99% for all trisomies and fetal aneuploidy, are highly invasive and have a potential risk to the health of the mother and fetus (up to cause the ' abortion).

The following table compares the advantages and the limitations of current prenatal diagnostic test non-invasive and invasive with latest-generation test performed on maternal blood.
TEST TYPE OF SAMPLE ADVANTAGES LIMITI
Screening tests of the 1st trimester of pregnancy
based on the combination of biochemical markers and ultrasound data (PAPP -A , free β - hCG and NT)
Non-invasive:
- Maternal Blood Sampling
- Data sonographic
- Secure: extremely limited risk for the mother and the child
- Reasonable costs
Indirect tests on a statistical basis
Multiple visits to screen
Up to 5% of false positives
Up to 30% of false negatives
Amniocentesis - chorionic villus sampling
(Chromosome analysis)
Invasive:
- Removal of amniotic fluid
- Withdrawal chorionic villi
- High diagnostic acccuratezza
- Possibility of cytogenetic or molecular testing
Risk of miscarriage ' (0.5 - 1 % )
Possibility 'of complications for the mother
High cost for the patient and for the health system
Non-invasive test using fetal DNA
First-generation test (shotgun sequencing)
Non invasive:
- Blood sample
- Accurate
- Sicure
High cost for the patient
Limited to the detection of fetal trisomy sun
Harmony Prenatal Test
Direct test DNA
Non invasive:
- Maternal Blood Sampling
- Accuracy > 99 % for Down Syndrome
- Sicure
- Efficient and economical
- Customized quantitative results
 

What if Harmony Prenatal Test gives a positive outcome

Any positive result, after appropriate genetic counseling, can be confirmed by chromosome analysis by amniocentesis.

What CRABioN does
• CRABioN offers free genetic counseling before the test;
• CRABioN offers free post-test counseling and amniocentesis with fetal karyotype when Harmony Prenatal Test produces a positive result.

Testing Features

Who has access to Harmony Prenatal Test
• Harmony Prenatal Test can be performed from the 10th week of pregnancy.
• It can perform in the event of a spontaneous pregnancy with a single fetus and from fertilization "in vitro" fertilization (IVF , ICSI) either with self - donation is from donors not parental oocytes, but always in the presence of a single fetus.
• You can carry in case of spontaneous twin pregnancy and "in vitro" fertilization with self- donation of oocytes.
• In twin pregnancies is still not possible to test for the X and Y chromosomes, but only for chromosomes 13, 18, 21.
• The test does not assess the risk of mosaicism, partial trisomy, or translocation.

ACOG (American College of Obstetricians and Gynecologists)[ www.acog.org], SMFM (Society for Maternal-Fetal Medicine)[www.smfm.org], ISPD (International Society for Prenatal Diagnosis)[www.ispd.org] e NSGC (National Society of Genetic Counselors)[ www.nsgc.org] recommend its use even in pregnancies considered to be at high genetic risk

Response times

12 working days

Simple

Just a common collection of executable maternal blood from the tenth week of gestation

Accurate

• Highly accurate detection of the most common trisomies and fetal aneuploidy
• Very low rate of false positives (less than 0.1 %)
• Customized results for clear interpretation also through graphics
• Possible confirmation of positive results offered by CRABioN free through genetic counseling and amniocentesis.