In high-risk pregnancies, some diagnostic tests can be applied, especially if there is a suspicion of hereditary disease. These tests are interventional tests, sometimes they can be risky for the mother and the baby. It should be done by experienced and expert personnel, in an appropriate environment. Interventions performed by inexperienced people in non-sterile environments can result in serious complications such as infections, unstoppable bleeding, or loss of the baby.

In high-risk pregnancies, some diagnostic tests can be applied, especially if there is a suspicion of hereditary disease. These tests are interventional tests, sometimes they can be risky for the mother and the baby. It should be done by experienced and expert personnel, in an appropriate environment. Interventions performed by inexperienced people in non-sterile environments can result in serious complications such as infections, unstoppable bleeding, or loss of the baby.

However, expert personnel and operations carried out under appropriate conditions do not pose a risk. Anesthesia is not generally used for these procedures. They are mostly painless, causing some discomfort. Since they are performed with imaging, the risk of harming the baby is also low.



Although these tests carry some serious risks, they give definite results about the disease. Thanks to these tests, the genetic code of the baby can be obtained without touching the baby. Genetic diseases can be understood before the baby is born and an intervention plan can be created if necessary.

Who are these tests for? 

  • Expectant mothers who are found to be at high risk in the screening tests for diseases such as Down Syndrome during pregnancy,
  • In cases where blood tests are not sufficient during routine or non-routine follow-ups in pregnant women,
  • In the presence of abnormal images in the routine or detailed ultrasound images made during pregnancy follow-ups, where a definite diagnosis cannot be made,
  • If there is a family history of genetic disease, if it poses a risk to the baby,
  • If the mother-to-be has a history of hereditary disease in previous births,
  • Those who have a genetic disease or carrier state in other genetic tests.

Diagnostic tests during pregnancy require good planning. Test selection is affected by factors such as the suspected disease, gestational week, placenta condition, and location in the uterus. Tests that can be used for diagnostic purposes during pregnancy include:

Chorionic villus biopsy (CVS):

It is the process of taking samples of chorionic villi, which are part of the placenta. Usually between the 11th and 13th of pregnancy. taken in weeks. Chorionic villi have the same genetic structure as the baby. Genetic analyzes of the suspected disease are made in the samples taken.

For the procedure, first of all, the placement of the placenta in the uterus is determined by ultrasound. In a way that does not harm the fetus, with the help of a thin needle, ultrasound is entered from the abdominal wall to the placenta and a small piece is taken. Although it is not very painful for the expectant mother, it is an uncomfortable procedure. There may be a risk of bleeding or miscarriage due to the procedure, but it cannot be said to be more risky than the disease tested. The process usually takes 5-10 minutes. Afterwards, the patient is taken to rest.

Amniocentesis:

The amniotic sac is a fluid-filled sac in which the baby settles during pregnancy and continues its vital activities. The fluid in the amniotic sac is called amniotic fluid. Amniotic fluid originates from the baby’s lungs, urine, and shed cells. Therefore, it has the same genetic structure as the baby.

For the procedure, first of all, the location of the amniotic sac and placenta is determined by ultrasound. Under the guidance of ultrasound, a sample of amniotic fluid is taken from a corner far from the placenta, without harming the fetus, by needle aspiration method. Although it varies depending on the gestational week in normal pregnancies, there is usually 200-300 ml of amniotic fluid. During the procedure, a sample of 20 ml of amniotic fluid is taken.

Usually between 16-22 weeks of pregnancy. applied in weeks. The process takes a few minutes. Genetic analyzes are performed on the samples taken in the laboratory environment. Plenty of rest is recommended for the patient after the procedure. It carries a risk of miscarriage or bleeding.

Cordocentesis (Fetal blood sampling):

It is the process of taking a blood sample from the baby’s umbilical cord or a suitable vein with the help of a needle. It can be applied from the 16th week of pregnancy or later until the birth. Definitive results can be obtained about the baby’s genetic diseases, blood level, blood diseases. It can also be used to give blood to the baby in diseases such as blood incompatibility and anemia.

Before the procedure, the location of the umbilical cord is determined in detail by ultrasound. It is entered through the abdominal skin under ultrasound guidance. At least 2 ml of blood sample is taken. The blood sample is subjected to genetic testing in the laboratory.

Fetal skin biopsy:

With the development of new methods that are less harmful over time, it is a method that is not used very often anymore. With the help of a device called a fetoscopy, a sample is taken from the baby’s skin tissue. It is often applied at the gestational week recommended by the physician. Pathological and genetic analyzes can be performed on the samples taken.

Diagnosis before pregnancy occurs (PGD) (Preimplantation Genetic Diagnosis):

In pregnant women who plan to have a child with the in vitro fertilization method, cell samples are taken from the embryo 2-5 days after the sperm and egg adhere to the uterus. Genetic analyzes are performed on these samples.


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