Genetic testing is when a blood test is given to prospective or expecting parents to look for abnormal genes that can lead to certain diseases in their baby.
Genetic testing is ideally done before you start trying to get pregnant, however because so many pregnancies are unplanned, many couples get screened early in pregnancy
Genetic tests are done by analyzing small samples of blood or body tissues. They determine whether you, your partner, or your baby carry genes for certain inherited disorders.
Talk to your doctor about any concerns you have regarding the need for the tests, any associated risks, how tests will be performed, or what the results will mean. Your doctor will run through information with you but if you have any concerns you can broach them with your doctor to put your mind at rest.
Genetic Testing Before and During Pregnancy
Getting screened before you try to conceive can give you reassurance or can help you make an informed game plan for pregnancy. If it turns out that you are both carriers, you can be prepared and choose to learn about certain prenatal tests to check whether your baby is healthy, or you can consider other options like egg or sperm donation or adoption.
For genetic testing before birth, pregnant women may decide to undergo amniocentesis or chorionic villus sampling.
Amniocentesis is a test performed between weeks 16 and 18 of a woman’s pregnancy. The doctor inserts a hollow needle into the woman’s abdomen to remove a small amount of amniotic fluid from around the developing fetus. This fluid can be tested to check for genetic problems and to determine the sex of the child
Chorionic villus sampling (CVS) is usually performed between the 10th and 12th weeks of pregnancy. The doctor removes a small piece of the placenta to check for genetic problems in the fetus. Because chorionic villus sampling is an invasive test, there’s a small risk that it can induce a miscarriage. Your health care professionals can talk you through any associated risks so you can make an informed decision.
Why Doctors Recommend Genetic Testing:
A doctor may recommend genetic counseling or testing for any of the following reasons:
- A couple is planning to start a family and one of them or a close relative has an inherited illness.
- An individual already has one child with a severe birth defect.
- A woman has had two or more miscarriages. A woman has delivered a stillborn child with physical signs of a genetic illness.
- A woman is pregnant and over age 34.
- A child has medical problems that might be genetic. A child has medical problems that are recognized as a specific genetic syndrome.
Genetic Screening
You may be referred to a genetic counselor if you or your partner has any risk factors, including:
- a family history of genetic disease
- if you’ve had recurrent miscarriages
- if you’ll be 35 or older when you give birth
Genetic screening before pregnancy can help reassure you that your child won’t be at risk for these diseases. And if your baby will be at risk, it can give you the opportunity to discuss your options.
Although advances in genetic testing have improved doctors’ ability to diagnose and treat certain illnesses, there are still some limits. Genetic tests can identify a particular problem gene, but can’t always predict how severely that gene will affect the person who carries it.