What is a prenatal ultrasound? When should they be performed?

Prenatal tests are various types of tests that are carried out during intrauterine development. Their goal is the early detection of malformations and genetic defects, as well as the control of fetal conditions. For some abnormalities, it is possible to schedule treatment immediately after birth or while still pregnant. Prenatal tests are divided into invasive (including amniocentesis, chorionic villus biopsy) and non-invasive (e.g. PAPP-A test, prenatal ultrasound, NIFTY test).

What is a prenatal ultrasound?

Prenatal ultrasound is an ultrasound during which the doctor performs a comprehensive evaluation of the developing fetus. This allows early detection of certain birth defects, including genetic ones. Depending on the trimester, other parameters are taken into account. During the first ultrasound, the doctor primarily measures nuchal fold translucency and determines the age of the pregnancy. In the second trimester, he focuses on a thorough evaluation of the baby’s body structure and internal organs, and during the last prenatal ultrasound he additionally determines the rate of fetal growth and the location of the placenta.

Prenatal ultrasound can detect trisomy of chromosomes: 21 (Down syndrome), 18 (Edwards syndrome) and 13 (Patau syndrome), defects of internal organs (such as the heart), limbs and neural tube.

Prenatal ultrasound should be performed on every pregnant woman. It is also recommended that another test – the PAPP-A test– be performed at the same time. It involves taking a blood sample from a pregnant woman and determining the concentration of the free beta-hCG subunit and protein A. This allows for a more accurate assessment.

Why is a prenatal ultrasound performed?

Prenatal ultrasound is performed to make a comprehensive assessment of fetal development. The purpose of the study is to assess:

• gestational age based on CRL, or fetal length from the top of the head to the buttocks,
• The structure and functioning of internal organs,
• The development of the limbs, head, trunk and other parts of the body,
• fetal movements,
• nuchal translucency,
• nasal bone structure,

and determine the risk of genetic or developmental defects.

In addition, during the prenatal ultrasound, the placenta is also evaluated – its size, position and appearance.

When should a prenatal ultrasound be performed?

The first prenatal ultrasound should be performed at the beginning of pregnancy, which is between 11 and 14 weeks. This is the right time to assess the translucency of the nuchal fold, since the result obtained is considered the most authoritative. Earlier the fetus is too small, and later it adopts a different position (bends the head), which makes it difficult to assess this parameter.

It is recommended that the test be performed 3 times. The second prenatal ultrasound is performed between 18 and 22 weeks, which is why it is referred to as a “midterm” ultrasound. For the last one you need to report between 28 and 32 weeks of pregnancy.

What does a prenatal ultrasound look like?

Prenatal ultrasound is performed in the supine position, using an abdominal probe (and sometimes a transvaginal probe if the baby’s positioning requires it). During the examination, the doctor makes a thorough assessment of all internal organs of the fetus and its anatomical structure (lower and upper limbs, chest, trunk, head). He also pays special attention to the nasal bone and the subcutaneous tissue in the nuchal area. Prenatal ultrasound is non-invasive, painless and requires no special preparation on the part of the pregnant woman.

Prenatal ultrasound price

The price of prenatal ultrasound ranges from PLN 150-250. Women over the age of 35 can perform them free of charge. Sometimes various preventive programs are organized aimed at pregnant women, so that they do not pay the cost of prenatal tests.

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