Non-Invasive Prenatal Testing
If you are a mom-to-be looking for reassurance about your pregnancy, there is exciting news! Generation® Non-Invasive Prenatal Testing (NIPT) offers greater accuracy, less discomfort, and virtually no risk to the baby. It’s the ultimate in prenatal testing.
Introducing Non-Invasive Prenatal Testing
Generation® Non-Invasive Prenatal Testing (NIPT) delivers highly specific genetic screening information comparable to invasive diagnostic techniques. That means less risk of miscarriage, less stress, less discomfort, and less hassle while still offering the highest accuracy.
How Does it Work?
The latest diagnostic technology has shown that a pregnant woman’s blood contains a small amount of fetal DNA. Accurate blood tests can now reveal information about the fetus earlier more safely than other types of tests. During the screening, DNA from the mother and fetus is extracted from a maternal blood sample to screen for the increased chance for specific chromosome problems, such as Down syndrome. This screening can also provide information about fetal sex and rhesus (Rh) blood type.
What is Detected?
Humans have 23 pairs of chromosomes, which are strands of DNA and proteins that carry genetic information. A trisomy is a chromosomal condition that occurs when there are three copies of a particular chromosome instead of the expected two. NIPT determines the risk of three fetal trisomies by measuring the relative amount of chromosomes in the mother’s blood.
Who Can Get the Test?
Generation® Non-Invasive Prenatal Screening is recommended for women who are at least 10 weeks pregnant and have adequate counseling regarding the options, benefits, and limits of first and second-trimester screening. Our genetic counselor will discuss whether this screening will benefit you and how to interpret the results.
Although women with a lower risk may choose NIPT, according to the American Congress of OBGyn (ACOG, 2015), NIPT is currently recommended for women who may be at increased risk for affected pregnancies due to the following reasons:
- Maternal age 35 or higher
- Ultrasound markers suggestive of anomalies
- Increased risk suspected during routine screening
- Suggestive history, i.e. previous pregnancy with chromosome abnormality
Why It’s Done.
Generation® Non-Invasive Prenatal Screening can be used to screen for fetal sex, fetal rhesus (Rh) blood type and the increased chance for specific chromosome problems, including:
- Down syndrome testing (Trisomy 21)
- Trisomy 18 testing
- Trisomy 13 testing
- Trisomy 16 testing
- Trisomy 22 trisome
- Triploidy testing
- Sex chromosome aneuploidy
Generation® Non-Invasive Prenatal Screening is much more sensitive and specific than traditional first and second-trimester screening, such as the first-trimester screening and the quad screen. As a result, Generation® Non-Invasive Prenatal Screening can often help women who have certain risk factors avoid invasive testing that carries a slight risk of miscarriage, including amniocentesis and chorionic villus sampling (CVS).
Your health care provider might recommend Generation® Non-Invasive Prenatal Screening first if:
- You have risk factors for having a baby who has a chromosomal condition. Risk factors might include older maternal age or having previously given birth to a baby who has Down syndrome, trisomy 13 or trisomy 18. Your health care provider might also recommend Generation® Non-Invasive Prenatal Screening if you’ve received worrisome results from another prenatal screening test.
- You’re a carrier of an X-linked recessive disorder. X-linked recessive disorders, such as Duchenne muscular dystrophy or a blood-clotting disorder (hemophilia), typically affect only males. Generation® Non-Invasive Prenatal Screening can determine fetal sex earlier than an ultrasound. However, the screening won’t determine if the fetus has the disorder. Depending on your test results, our genetic counselor can help you understand the next steps.
- You have an Rh negative blood type. Generation® Non-Invasive Prenatal Screening can determine the Rh factor of the fetus. If you’re Rh-negative and the fetus is Rh positive, you might produce Rh antibodies after exposure to fetal red blood cells. This is typically not a concern during a first pregnancy but can be a concern during subsequent pregnancies.
Generation® Non-Invasive Prenatal Screening has been shown to be less effective if you are:
- Pregnant with multiples
- Pregnant via a donor egg
- Pregnant and a surrogate
- Less than 10 weeks pregnant
Generation® Non-Invasive Prenatal Screening poses no physical risks for you or your baby.
While Generation® Non-Invasive Prenatal Screening might cause anxiety, it might help you avoid the need for more invasive tests, treatment or monitoring during your pregnancy.
Keep in mind, however, that Generation® Non-Invasive Prenatal Screening doesn’t screen for all chromosomal or genetic conditions. A negative test result does not ensure an unaffected pregnancy.
How You Prepare.
If you’re interested in Generation® Non-Invasive Prenatal Screening, talk to your health care provider about its availability. Also, consider checking to see if your health insurance covers the cost of Generation® Non-Invasive Prenatal Screening.
Before you undergo Generation® Non-Invasive Prenatal Screening, your health care provider or our genetic counselor will explain the possible results and what they might mean for you and your baby. Be sure to discuss any questions or concerns you have about the testing process.
What You Can Expect.
During Generation® Non-Invasive Prenatal Screening a maternal blood sample is taken and sent to our lab. The lab analyzes the maternal and fetal DNA in the blood sample. A higher than expected ratio of chromosome 21 sequences indicates, for example, the likely presence of trisomy 21 in the fetus. Trisomy 21 is the most common cause of Down syndrome.
Typically, test results are available within two weeks.
- Chromosomal conditions. If the test results are normal, you might not need further testing. However, if results indicate an increased risk that the fetus has a chromosomal abnormality, amniocentesis or CVS will be offered. Further testing using the sample from amniocentesis or CVS can be used to confirm the diagnosis.
- Fetal sex. If you’re the carrier of an X-linked recessive disorder and the test results indicate that you’re carrying a girl, you might not need further testing. If the test results indicate that you’re carrying a boy, amniocentesis or CVS might be offered for further evaluation. In most situations, these tests can be used to diagnose a genetic disorder linked to the X-chromosome.
- Rh factor. If you’re Rh negative and the test results indicate that the fetus is Rh negative, you won’t need medication to prevent your body from producing Rh antibodies during your pregnancy. If the test results indicate that the fetus is Rh positive and you’ve previously become sensitized, your baby will be carefully monitored.
Chromosomal abnormalities can’t be corrected. If your baby is diagnosed with a chromosomal abnormality, you’ll need to decide whether to continue with your pregnancy or what steps to take to care for your baby during pregnancy and after he or she is born. Your health care provider or our genetic counselor can help answer any questions you might have. This down syndrome testing gives you the information you need to prepare.
Regardless of the results of Generation® Non-Invasive Prenatal Screening, if you have risk factors that suggest your baby might be at increased risk of a chromosomal or genetic condition, you have the option of undergoing amniocentesis or CVS. This down syndrome testing gives you the information you need to prepare.
For information about our other prenatal services, please click here for the Center for Medical Genetics website.