Genetic Screening

The Nuchal Translucency ultrasound is performed at the end of the first trimester between 12 and 13.5 weeks of pregnancy. This ultrasound measures the fluid collection at the back of the baby’s neck. This space can be abnormal in babies with chromosome problems like Down Syndrome and other birth defects, including heart defects. The sonographer will perform this test on top of your abdomen. This exam should not cause pain just a small amount of pressure. Although this is a very exciting time, it is too early to determine the baby’s gender at this exam. This ultrasound can take up to 40 minutes, although sometimes can be done faster if the baby is cooperative. Once the sonographer has completed the ultrasound you will meet with the provider to go over the results.

The first trimester screen is a blood test taken within 5 days of the nuchal translucency ultrasound. This test measures two proteins within the mothers’ blood, which can be affected by chromosome problems like Down Syndrome. We will combine the results of this blood test with the nuchal translucency ultrasound to provide a risk assessment of the chance of the baby to have chromosomal problems like Down Syndrome. This test does not give you a yes or no answer but it will give you a result of low risk or high risk. If the test comes back as high risk, your provider may order additional testing to confirm this result. This test may or may not be covered by insurance. It is the patient’s responsibility to verify coverage thru insurance prior to testing.

Prenatal cell-free fetal DNA testing is a screening test for possible chromosomal abnormalities affecting the current pregnancy. The test offered at Christie Clinic is called Claritest. It is offered to women considered to be high risk including: older than age 35 at delivery; previous child with chromosome abnormalities; or abnormal genetic screening testing including first trimester screen or nuchal translucency ultrasound. The Claritest is a blood test that is collected locally at Christie Clinic and processed through GenPath. This test can be done any time after 10 weeks of pregnancy. The results will reflect if there is a risk for the baby to be affected by a chromosomal abnormality such as Down syndrome. The Claritest will not give a definitive yes or no answer regarding abnormalities. The results will include low risk screen or high risk screen. The Claritest may or may not be covered by insurance. It is the patient’s responsibility to verify coverage thru insurance prior to testing.

Quadruple Marker Test (“Quad screen”) or the second trimester screen is done between 15 weeks and 22.5 weeks gestation. It measures four different levels in the mother’s blood- Alpha-fetoprotein (AFP), Human chorionic gonadotropin (HCG), Estriol, and Inhibin A. The results will provide a risk assessment for chromosomal problems like Down Syndrome or structural problems like spina bifida. This test is a screening test and therefore cannot determine with certainty that the baby has one of these problems. The test estimates the risk that the baby might be affected. The “Quad screen” may or may not be covered by insurance. It is the patient’s responsibility to verify coverage thru insurance prior to testing.

AFP stands for alpha-fetoprotein. This test measures the level of AFP in the mother’s blood, and these results are combined with the mother’s age and ethnicity to determine the risk for potential birth defects. A higher level of AFP might suggest a defect such as spina bifida or anencephaly. Spina bifida is a problem in the development or closure of the spine or the abdomen. Anencephaly is a problem where the largest part of the baby’s brain does not develop. Most babies with anencephaly cannot survive after birth. This blood test is performed between 15 and 22.5 weeks of pregnancy. This test can be performed regardless of first trimester screening results as it is screening for different abnormalities. The information from this test will be combined with the results of an ultrasound to provide a risk assessment of the baby being affected with structural problems such as spina bifida. The AFP screen may or may not be covered by insurance. It is the patient’s responsibility to verify coverage thru insurance prior to testing.

Cystic fibrosis testing is a blood test that can be taken before or during pregnancy. It is possible for you to not have any symptoms yet still be a carrier with one abnormal gene. About 1 in 27 patients without the disease will be a carrier. If you have two abnormal gene copies then you will have this disease. If both parents have an abnormal copy of this gene the baby has a 1 in 25% chance of having this disease. Cystic fibrosis is a disease that affects breathing and digestion. Testing for this disease may or may not be covered by insurance, please check with your provider.

Spinal Muscular Atrophy (SMA) is a genetic disease affecting the part of the nervous system that controls voluntary muscle movement. SMA involves the loss of nerve cells called motor neurons in the spinal cord and is classified as a motor neuron disease. This will cause muscle weakness and even paralysis. There is a blood test for SMA that can be taken before or during pregnancy. Patients without any symptoms could still be a carrier of one abnormal gene copy. Patients with two abnormal gene copies will have this disease. Around 1 in 50 patients without the disease will still be a carrier of one abnormal copy of the disease. If both parents have one abnormal copy the baby has a 1 in 25% chance of having this disease. Testing for this disease may or may not be covered by your insurance, please check with your provider.