Non Invasive Genetic Screening Tests for Women 35 years and over
Cell Free fetal DNA test >10 weeks
The cell free DNA test is a newly available genetic screening test that takes a maternal blood sample to find circulating fragments of baby’s DNA. This can help determine if he or she may have certain genetic conditions such as a chromosome abnormality. It is not recommended as a first line test for women who are low risk, or have a multiple pregnancy. This test is appropriate for women >35 yo at time of birth, previous abnormal screening results, a previous child affected by trisomy, or parents who carry a chromosomal translocation. It screens for Trisomy 21 (>99% accuracy) , Trisomy 18 (97% accuracy), Trisomy 13 (91% accuracy) and sex chromosome anomalies (91% accuracy). It is not as accurate in women under 35 years old. To check insurance benefits : CPT code 81420
Nuchal Translucency 12w-13w6d
One of the most accurate screening tests for the common trisomies (extra chromosomes) is the Nuchal Translucency First Trimester Screen. It is appropriate as a first line test for women under 35 years old who want to know their risk for a fetal chromosome abnormality. This is also a first line test for twin gestations. To perform the test an ultrasound is done between 12 weeks and 13 weeks and 6 days. It combines a measurement of the fetal neck thickness with a blood test that analyzes markers associated with trisomy. It has a 90% detection rate for Trisomy 21 (Down syndrome) and Trisomy 18. There is a 5% false positive rate.
Insurance CPT codes to check benefits are: 84163, 82397, 76813
Penta Screen 15 wks- 22w6d
The Penta screen is a second trimester blood test that analyzes your blood for markers of the most common trisomies (21,18,13) as well as neural tube defects. It is performed if you decide later in your pregnancy that you would like genetic screening, you begin prenatal care after the window of first trimester screening, or due to insurance coverage variance. It has an 83% detection rate for Trisomy 21, 73% for Trisomy 18, and 95% for neural tube defects. There is a 3-5% false positive rate.
Insurance codes to check benefits are: 82105, 82397, 82677, 84702, 86336, 81512
The alpha fetoprotein (AFP) is a blood test performed to determine the risk of a fetal neural tube defect such as spina bifida. This test and information can be valuable in preparing for the delivery of your baby. The AFP is typically done for a woman who has already performed first trimester aneuploidy screening. This is also an option for women who desire screening for open neural tube defects without testing for trisomy. The test detects 71-90% of open neural tube defects with a 1-3% false positive rate.
Insurance code to check benefits is CPT code 82105
Fetal Anatomy Survey Ultrasound- 20 weeks
This is an in depth ultrasound to review the baby’s anatomy from head to toe, to look for birth defects as well as signs (markers) for genetic syndromes. This is the time you may be able to find out the sex of your baby (if the genitals are visible).
Invasive Diagnostic Tests
Chorionic Villi Sampling (CVS) 10w-13w
The CVS is an invasive test that can diagnose if there is a genetic abnormality. It samples tissue from the placenta to obtain DNA and determine if a baby has a genetic condition like Down syndrome. CVS is done at a specialist’s office between 10 to 13 weeks of pregnancy. It carries a risk of miscarriage of 1 in 300 women and can be done as a first line test for high risk pregnancies, or a second line test if a screening test is abnormal.
Insurance codes to check benefits are : CPT 59105, 88267
Amniocentesis 15w and up (Amnio)
The amniocentesis (sometimes abbreviated “amnio”) is an invasive test that can diagnose if there is a genetic or sometimes other abnormality. It is performed by taking a sample of the amniotic fluid through the mother’s abdomen which enables a full genetic analysis of fetal cells. It carries less than 1:300 risk of pregnancy loss. Reasons for performing this test are similar to those of a CVS.
Miscellaneous Testing Options
Cystic Fibrosis Carrier Screening (preconception or first visit ideal)
A cystic fibrosis carrier screen is a blood test that can done at any time before or during the pregnancy, however ideally preconception or early in pregnancy. It is performed to see if you carry of the genes that cause CF. CF is a disease that affects breathing and digestion. If you were to test positive as a carrier, we recommend your partner be tested as the condition can be passed on if both partners carry an abnormal gene. The risk for being a carrier of the CF gene varies within different ethnicities. It is highest in the caucasian population, where 1 in 25 people may be carriers. For more information visit: http://www.mayoclinic.org/diseases-conditions/cystic-fibrosis/symptoms-causes/dxc-20211893
The insurance code to check benefits are: CPT code 81220 ICD 10 code Z31.430
Ashkenazi Jewish Panel/Tay Sachs Screening (preconception or first visit ideal)
Diseases commonly grouped together as “Jewish Genetic Disorders” (JGDs) range in incidence from 1/900 to 1/40,000 in the Jewish community, specifically those individuals of Ashkenazi (eastern European) heritage. The overall carrier rate in this population is significant, with between 1 in 4 and 1 in 5 Ashkenazi Jews carrying a mutation for any one of these disorders. Therefore, there is a blood test that can screen to see if you are a carrier for one of the disorders that are most prevalent in this community. If you were to test positive as a carrier, it is recommended that your partner be tested as you can pass that condition to your baby. For more information visit: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110977/
The insurance codes to check benefits are: ICD-10 code Z14.8 , CPT 81220, 81200, 81251, 81242, 81209, 81255
Spinal Muscular Atrophy (SMA)
SMA is a condition affecting 1 in 6000 to 1 in 10,000 babies annually. It causes death of motor neurons in the spinal cord that leads to atrophy and degeneration of muscles; it can be fatal in infancy due to respiratory failure. Carrier rates differ by ethnicity, ranging from 1 in 35 in caucasians to 1 in 117 in the hispanic population. Testing for SMA carrier status can be done at any time prior to or during pregnancy.