Genetic screening is a process used to determine a child's risk
of inheriting certain diseases or birth defects from his or her
parents. Couples planning to have a baby might be concerned about
illnesses that have occurred in family members. The best
time to have genetic screening is before a pregnancy,
but it can also be done at specific time points during a pregnancy.
There are several tests that look for different genetic disorders.
Keep in mind that genetic testing is not done for every pregnancy. Some have an increased risk of having a child with a genetic condition. Here are some common reasons your healthcare provider may recommend genetic screening: Mother or father has family members with inherited disordersMother is 35 years old or older when you deliver your
babyPrevious child with a hereditary disease or
Previous stillbirths or several
miscarriagesAbnormalities in the pregnancy, such as too much or too little serum
alpha fetoprotein (AFP)
Conditions that your healthcare provider may screen for include: Down syndromeCystic
fibrosis—Caused by two defective genes, affecting the lungs and pancreas.
Tay-Sach's disease—A brain
disorder, which is more common in people of Eastern European (Ashkenazi) Jewish descent, that causes early death.Thalassemia—A type of anemia caused by abnormal red blood cells. The condition is more common in people from southeast
Asia, China, and Mediterranean countries, such as Greece and Italy.
Hemophilia—A blood clotting disorder.
Sickle cell anemia—More common in African Americans of sub-Saharan origin, affecting the red blood cells.
Any possible genetic defect that may affect your child in the future, such as BRAC mutations that increase the risk of breast and ovarian cancers.
You should find out about the medical history of your family,
including hereditary diseases in your mother's and father's
families. If possible, ask your parents and your partner's parents
about any abnormalities, disabilities, or
family. Make a record of any of the following personal
Exposure to environmental hazards before or during pregnancy
or other radiation; chemicals used at work, home, or with
Any prescription or nonprescription drugs you took before
pregnancy or before you knew you were pregnantAny history of alcohol or drug use
During the genetic screening process, your healthcare provider
will ask you and your partner for a detailed family history of
diseases, disorders, and birth defects. You may be given blood
tests. If you are already pregnant, you might be given tests to
examine the chromosomes and condition of the fetus. Examples of
genetic screening tests given during pregnancy include: Blood tests to check the levels of alpha fetoprotein, with possible follow-up tests to look
for neural tube defectsUltrasound
scans to check for birth defects of the brain,
heart, spine, arms, legs, and other organs
Chorionic villus sampling (CVS) to check for chromosomal
to check for chromosomal abnormalities
After the screening and tests, your healthcare provider will
discuss the results with you and make recommendations about any
treatment that may be beneficial. Treatment is a personal choice
that is left entirely up to you. Your healthcare provider should
provide you with lots of information about treatment options so
that you can make informed choices.
Genetic counseling. American Pregnancy Association website. Available at: http://americanpregnancy.org/getting-pregnant/genetic-counseling. Updated March 2011. Accessed December 9, 2014.
Routine prenatal care. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 4, 2014. Accessed December 9, 2014.
Routine tests in pregnancy. American Congress of Obstetricians and Gynecologists website. Available at: http://www.acog.org/~/media/For%20Patients/faq133.pdf?dmc=1&ts=20121217T1134335563. Accessed December 9, 2014.
Screening for birth defects. American Congress of Obstetricians and Gynecologists website. Available at: http://www.acog.org/~/media/For%20Patients/faq165.pdf?dmc=1&ts=20121217T1134388121. Accessed December 9, 2014.
Last reviewed December 2014 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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