What are Genetic Screening Tests? Methods, Benefits and Importance in Pregnancy
Genetic screening tests are examinations performed to evaluate certain disease risks inherited from the family or in the genetic structure of the individual. These tests help determine genetic diseases, congenital abnormalities and hereditary disorders. Genetic screening tests, especially performed during pregnancy, are of great importance to determine the baby's genetic disease risks.
What are Genetic Screening Tests?
Genetic screening tests are tests that analyze the genetic structures of individuals or couples and evaluate whether their babies may have certain genetic diseases. Genetic screening aims to detect disorders in genes and is especially recommended for expectant mothers during pregnancy.
Basic Features of Genetic Screening Tests:
- Detection of Hereditary Diseases: Genetic tests evaluate the risk of diseases in the family's genetic history being passed on to the baby.
- Prenatal Detection: Possible genetic abnormalities in the baby can be detected with tests performed during pregnancy.
- A Preventive Approach: Genetic screening is an important step in terms of early diagnosis and preventive treatment.
These tests play a critical role in determining possible risks, especially during pregnancy, and planning for a healthy birth process.
Why Are Genetic Screening Tests Performed?
Genetic screening tests are performed to determine the genetic disease risks in the individual's or family's history. This screening is used to evaluate the presence of hereditary diseases and to determine the risk of these diseases in the unborn baby.
Reasons for Genetic Screening Tests:
- Hereditary Diseases: Hereditary diseases such as Down syndrome, Edwards syndrome, Turner syndrome can be detected with genetic screening.
- Consanguineous Marriages: Genetic risks may be higher in couples who have had consanguineous marriages.
- Age Factor: The probability of some genetic abnormalities increases if the mother is over 35 years old.
- Past Pregnancy Problems: If you have previously given birth to a baby with a genetic disease or These tests are important in women who have had a miscarriage.
In such cases, genetic screening tests are performed to both increase the safety of the pregnancy process and to minimize postpartum complications.
The Importance of Genetic Screening Tests During Pregnancy
Genetic screening tests performed during pregnancy are of critical importance to evaluate the genetic health of the baby and to detect possible diseases before birth. Early diagnosis can provide a chance for prenatal treatment or intervention, allowing the baby to be born healthy.
Benefits of Genetic Screening Tests During Pregnancy:
- Early Diagnosis: Genetic tests performed during pregnancy provide early diagnosis of genetic disorders that may occur in the baby.
- Birth Planning: If a genetic disease is detected in the baby, the necessary health support and treatment plans can be created after birth.
- Determining the Risk: If there is a history of genetic disease in the family, the baby's risk status is determined and appropriate precautions are taken.
These tests are recommended screening tests during pregnancy to ensure the health of the expectant mother and the baby and to prevent possible complications. tests.
How Are Genetic Screening Tests Done?
Genetic screening tests can be done with several different methods during or before pregnancy. The most common methods include blood tests, ultrasound, and amniocentesis.
Genetic Screening Test Methods:
- Blood Test: Data on the baby's genetic structure is obtained with a blood sample taken from the mother-to-be. Tests such as NIPT (non-invasive prenatal testing) are performed with this method.
- Ultrasound: Ultrasound is used to evaluate abnormalities in the baby's anatomical structure.
- Amniocentesis: The baby's chromosomes are examined using samples taken from the pregnancy fluid.
- Chorion Villus Biopsy (CVS): A small tissue sample is taken from the placenta to check for genetic disorders.are eliminated.
The doctor determines which test to be applied according to the week of pregnancy and the baby's condition.
When Are Genetic Screening Tests Performed?
The timing of genetic screening tests varies depending on the period of pregnancy in which they are performed. Tests generally performed in the early stages of pregnancy provide important information about the baby's genetic health status.
Appropriate Times for Genetic Screening:
- First Trimester Screening: Screening performed between weeks 11-14 is important for Down syndrome and other chromosomal abnormalities.
- Second Trimester Screening: 16-20. Neural tube defects and other congenital disorders can be detected with screening performed at weeks.
- Amniocentesis: This test, usually performed between weeks 15-20, is used to detect chromosomal disorders.
Each test has a different time interval and your doctor will determine the most appropriate times according to your pregnancy.
Types of Genetic Screening Tests
There are different genetic screening tests that can be performed during pregnancy. Each test is used to detect specific genetic abnormalities.
Types of Genetic Screening Tests:
- First Trimester Screening: Screening performed in the first 3 months of pregnancy is performed to detect chromosomal abnormalities such as Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18).
- Second Trimester Screening: Alpha-fetoprotein (AFP) testing and quadruple screening are used to evaluate neural tube defects and other genetic problems.
- Non-invasive Prenatal Testing (NIPT): A blood sample taken from the mother-to-be is used to examine the baby's DNA and evaluate genetic disease risks.
- Amniocentesis: A sample of amniotic fluid is used to examine the baby's chromosomes.
- Chorion Villus Biopsy (CVS): A tissue sample from the placenta can be used to detect genetic disorders in the early stages.
These tests can be performed at different stages of pregnancy and each is designed to identify a specific genetic risk.
Benefits of Genetic Screening Tests
Genetic screening tests provide critical information to parents about pregnancy and birth by detecting genetic diseases in the unborn baby at an early stage.
Main Benefits of Genetic Screening Tests:
- Early Diagnosis and Intervention: Thanks to genetic tests, genetic diseases that the baby may have are diagnosed at an early stage and a treatment plan can be created.
- Planning the Pregnancy Process: More informed decisions can be made about the pregnancy process by determining risk factors.
- Healthy Birth Opportunity: Genetic screenings prevent possible congenital disorders and increase the chance of giving birth to a healthy baby increases.
These benefits show that genetic screening tests are of great importance for both mother and baby health.
Are There Risks of Genetic Screening Tests?
Many genetic screening tests are non-invasive and do not carry any serious risks. However, it is known that the risk of miscarriage may increase slightly with some invasive tests (such as amniocentesis).
Possible Risks of Genetic Screening Tests:
- Amniocentesis and CVS: The risk of miscarriage is less than 1%, but these tests should still be performed carefully, in accordance with the doctor's recommendation.
- Non-invasive Tests: Tests such as blood tests and ultrasounds are safe and do not pose any risks.
Your doctor will explain the risks of each test to you in detail and offer you the safest option.
How Are Genetic Screening Results Interpreted?
Genetic screening test results are usually reported as “normal” or “abnormal.” Normal results indicate that the baby is not at risk for a genetic disease, while abnormal results may require further testing.
Interpreting Results:
- Normal Results: This means that there is no problem with the baby’s genetic health.
- Abnormal Results: More detailed testing and evaluation may be necessary. Abnormal results do not necessarily mean that there is a genetic problem, but further testing is recommended.
The results are carefully evaluated by your doctor and the necessary steps are takenis thrown away.
What to Do After Genetic Screening
According to the results of genetic screening tests, a normal process may continue, or if abnormal results are obtained, further tests or treatment plans may be applied.
In Case of Abnormal Results:
- Advanced Tests: Results can be confirmed with tests such as amniocentesis or CVS.
- Counseling: Genetic counselors inform the mother and father about the results and provide guidance on the decisions that need to be made.
- Treatment Plan: In necessary cases, a prenatal treatment plan can be created.
Proceeding in line with your doctor's recommendations according to the results is important.
Who Are Suitable for Genetic Screening Tests?
Genetic screening tests are especially recommended for families with a history of genetic diseases and pregnant women with certain risk factors.
People Suitable for Genetic Screening Tests:
- Those with a Family History: Couples with a family history of genetic diseases.
- Advanced-Age Mothers: The risk of genetic disorders increases in pregnant women over the age of 35.
- Women Who Have Experienced Miscarriages in the Past: Mothers-to-be who have experienced recurrent miscarriages in the past.
Couples who meet these criteria are among the priority candidates for genetic screening tests takes.
Frequently Asked Questions (FAQ)
1. When are genetic screening tests performed?
They can be performed between weeks 11-14 in the first trimester and weeks 16-20 in the second trimester.
2. Are genetic screening tests mandatory?
No, these tests are recommended but depend on the decision of the expectant mother.
3. Are genetic screening results definitive?
Some tests can provide up to 99% accurate results, but in abnormal results, further tests may be required for definitive diagnosis.
4. Are genetic screening tests risky?
Non-invasive tests are risk-free. In invasive tests such as amniocentesis, the risk of miscarriage is very low.
5. Is it necessary to have a genetic screening test?
It may be recommended by the doctor considering the risk factors, but it is not necessary.
