Prenatal tests – is it worth doing and when? [WE EXPLAIN]

In line with its mission, the Editorial Board of MedTvoiLokony makes every effort to provide reliable medical content supported by the latest scientific knowledge. The additional flag “Checked Content” indicates that the article has been reviewed by or written directly by a physician. This two-step verification: a medical journalist and a doctor allows us to provide the highest quality content in line with current medical knowledge.

Our commitment in this area has been appreciated, among others, by by the Association of Journalists for Health, which awarded the Editorial Board of MedTvoiLokony with the honorary title of the Great Educator.

Every pregnant woman would like to be sure that her baby is born healthy. In order to find out about the proper development of the fetus and to be able to carry out appropriate treatment while still in the womb, it is worth performing prenatal tests. Recommended by the Polish Society of Gynecologists and Obstetricians, they allow to estimate the risk associated with developmental defects.

Prenatal tests for pregnant women

Prenatal tests, although reimbursed only in selected cases, should be performed by every woman expecting a baby. Correctly conducted, they allow the estimation of the probability of giving birth to a child with birth defects. Such information at the beginning of pregnancy is extremely valuable because it allows parents to prepare for the birth of such a baby and at the same time allows for appropriate procedures in the fetal period – if it is possible. Diagnosing the disease before childbirth also allows doctors to develop a plan of action after the birth of a baby. They are then prepared, for example, to operate on a sick child after delivery, which increases its chances of recovery.

Prenatal tests also provide information on the inheritance pattern and the consequences of any birth defects. The current development of medicine allows you to start appropriate treatment while still in the womb. Prenatal examinations, due to their nature, can be divided into invasive and non-invasive. Invasive prenatal testing They are carried out only in justified cases, as they are associated with a high risk of miscarriage. This is due to the necessity of invasive material collection (during the procedure). However, invasive tests allow for a very accurate diagnosis of fetal development disorders.

What diseases can we diagnose with prenatal testing?

Prenatal examination allows to diagnose the following diseases:

  1. hemophilia,
  2. cystic fibrosis,
  3. Duchenne muscular dystrophy,
  4. Edwards syndrome,
  5. down syndrome,
  6. pląsawica Huntingtona,
  7. Patau team,
  8. meningeal and umbilical hernia,
  9. Turner syndrome,
  10. defects of the heart and urinary system,
  11. anemia.

What is non-invasive prenatal testing?

Are you wondering what is prenatal testing? Much depends primarily on their character – it is worth knowing that they are divided into non-invasive and invasive.

The following non-invasive prenatal tests include:

  1. Genetic ultrasound – it differs from regular ultrasound in that it is performed on very sensitive equipment and by an experienced doctor (preferably one who has a certificate). Prenatal ultrasound usually takes much longer than regular tests, sometimes up to an hour. During ultrasound, the gynecologist measures the thickness of the nape of the neck, gestational and yolk sac, dimensions and shape of the fetal organs, the baby’s nasal bone, heart rate, placenta, amniotic fluid, umbilical cord and the length of the femurs;
  2. double test (PAPP-A) – this is a blood test that is performed between 11 and 13 weeks of pregnancy. The mother’s blood is used to measure the concentration of substances that are markers of Patau syndrome, Down syndrome and Edwards syndrome. The substances are PAPP-A pregnancy protein and free beta-hCG, i.e. free beta subunit of chorionic gonadotropin;
  3. triple test – blood taken from a pregnant woman is analyzed for the concentration of beta-HCG, AFP pregnancy protein and free estriol (fE3). This test is performed between 14 and 21 weeks of pregnancy and is not compulsory, but can be performed by women of any age, although it is particularly recommended after the age of 35;
  4. fetal echocardiography – the test can be performed around the 20th week of pregnancy in order to diagnose congenital heart defects or circulatory disorders;
  5. The NIFTY test is a non-invasive prenatal test used to determine the risk of fetal trisomy in a child, based on the child’s DNA analysis. The sensitivity of this test exceeds 99%. The material for the study is taken from the mother’s blood;
  6. test IONAis a test for early assessment of the risk of genetic defects in a child (Patau, Down’s syndrome, Edwards syndrome). This test is especially recommended for women who have undergone in vitro fertilization, are over 35 years of age and for those who have a much older partner (especially over 55);
  7. test PANORAMAis a non-invasive screening test, thanks to which we can obtain important information about the course of pregnancy from the 9th week of pregnancy. The Panorama test, apart from assessing whether there is an additional chromosome in the fetus, allows to determine the sex of the child.

What is invasive prenatal testing?

Prenatal tests can also be invasive – they are performed then, when non-invasive tests indicate certain abnormalities. If a birth defect is suspected, the gynecologist may refer the patient to invasive prenatal tests, such as:

  1. amniocentesis – ultrasound-guided amniotic fluid collection is usually performed between the 15th and 20th week of pregnancy, as early amniocentesis (performed between 11th and 14th week of pregnancy) is associated with a higher risk of complications; the test allows you to carry out tissue culture of the collected material, determine the karyotype and detect with high accuracy chromosomal abnormalities of the fetus;
  2. Chorionic villus sampling (CVS) – the procedure is usually performed between the 11th and 14th week of pregnancy and involves collecting a chorion fragment (under ultrasound control) using one of the two methods, i.e. through the anterior abdominal wall or through the cervix; DNA or chromosomes are isolated from the sample thus obtained, and a cytogenetic test is performed;
  3. cordocentesis – a test involving the collection of umbilical cord blood by puncturing the umbilical cord; this test can be performed after the 20th week of pregnancy, and on its basis, diagnostics of fetal defects and haemolytic diseases can be performed.
Attention

Although non-invasive tests can accurately indicate the risk of certain diseases in the unborn child and can quite accurately (even 95%) exclude the disease, they are not the basis for a diagnosis. However, in order to diagnose a genetic disease, an invasive examination must be performed.

The invasiveness of these tests means that they are associated with a certain risk of complications. Therefore, they are usually performed with specific indications, and if possible, the deadlines in which they are recommended are followed to minimize the likelihood of complications. These complications include, among others: spotting, lower abdominal pain, bleeding, lower limb edema, anxiety, infections.

Keep in mind that invasive test miscarriages are very rare (risk up to about 1,3% in the case of chorionic villus sampling; 0,5-1% in the case of amniocentesis). Spontaneous miscarriages or deaths of the fetus are more frequent between 16 and 20 weeks of pregnancy, which occur in about 5% of pregnancies.

What prenatal tests look like depends on the type of test. For example, Genetic ultrasound consists in performing a detailed ultrasound examination taking into account such parameters as, for example, the presence of the nasal bone, assessment of the nuchal translucency, and the CRL dimension. Whereas test PAPP-A is a blood test that measures the levels of the protein PAPPA-A and the hormone beta-hCG.

Invasive research looks different. For example, amniocentesis involves the removal of a sample of amniotic fluid by puncturing the amniotic bladder. In this way, fetal cells are obtained, which are cultured in vitro, and then the karyotype of the child is determined.

According to the recommendations of the Polish Society of Gynecologists and Obstetricians, prenatal examinations should be performed between the 10th and 14th week of pregnancy. However, a lot depends on the type of examination, e.g. amniocentesis can be performed only after the 13th week of pregnancy. The first and second trimester tests are considered the most important.

The indications for prenatal tests are:

  1. worrying results of ultrasound and other pregnancy tests,
  2. family history of genetic diseases,
  3. mother’s age over 35,
  4. giving birth to a child with a genetic or developmental defect in a previous pregnancy.

Although every woman expecting a baby should undergo prenatal screening, the indications for them are:

  1. pregnant woman’s age – over 35;
  2. previous pregnancy which resulted in the birth of a child with a chromosomal abnormality;
  3. chromosomal aberration in one of the parents;
  4. family history of genetic diseases;
  5. in vitro fertilization.

Prenatal tests – price

There is a program of the National Health Fund (NFZ) under which a certain group of women can take advantage of prenatal tests free of charge. Among the criteria that a pregnant woman must meet are age (over 35) and cases of genetic diseases in the immediate family. On the other hand, women who would like to undergo prenatal screening, but are not entitled to a refund, must take into account the costs.

1. Amniocentesis – the price ranges from PLN 1300 to PLN 2000.

2. Test PAPP-A – about PLN 250

3. Double test and triple test – about PLN 250

4. Chorionic villus sampling – from PLN 1500 upwards.

5. Test Nifty – about PLN 2400

6. Harmony genetic testing – about PLN 2000

The content of the medTvoiLokony website is intended to improve, not replace, the contact between the Website User and their doctor. The website is intended for informational and educational purposes only. Before following the specialist knowledge, in particular medical advice, contained on our Website, you must consult a doctor. The Administrator does not bear any consequences resulting from the use of information contained on the Website.

Leave a Reply