You’ve just found out you’re pregnant. You’re excited, but you want to make sure the pregnancy is going well before you announce it to all your family and friends. Happily, there are now several screenings that can be performed in the first 10 to 14 weeks of pregnancy to detect your risk for chromosomal abnormalities, heart defects and other birth defects. Early testing has several advantages. When we diagnose problems early, we can provide appropriate care and give you the very best chance at a healthy pregnancy and delivery. Even if you have no risk factors or reason to worry, tests like an advanced ultrasound give you the reassurance that your pregnancy is proceeding normally.
Who should do your testing?
If you are going to do any testing in your first trimester, it should follow high quality genetic counseling so you get all the information you need about your potential risks and understand your options for tests or procedures. Tests are only as good as the technology used, the expertise of the clinician doing the screening and the ability of the physician to interpret the results. Some tests are only performed by medical specialists, such as perinatologists (also known as maternal-fetal medicine specialists). While many ob/gyn and radiology offices offer ultrasound testing, studies have shown that three times the number of abnormalities are detected when advanced testing is done by a specialist. When considering any screening during your first trimester, find a specialist who has considerable experience in performing the kind of test you require.
First-trimester screening options
Several non-invasive tests provide a good first look at your risk for complications. Your options may depend on your age, risk factors and general health.
First trimester screening: A blood test combined with a special ultrasound test can provide instant risk assessment for Down syndrome and other chromosomal abnormalities. This can decrease the number of false negatives and increase the true positive rates significantly over a blood test or ultrasound alone. Further testing is required if abnormalities are indicated.
Genetic testing of fetus: A relatively new, non-invasive screening uses a sample of the mother’s own blood to test fetal DNA and detect the risk for some chromosomal problems as early as 9 weeks into your pregnancy. This test is usually administered for women considered high risk and after genetic counseling.
Ultrasound: The most advanced ultrasound technology enables us to assess your risk for Downs syndrome and major fetal abnormalities such as spina bifida and heart defects between 11 and 13 weeks.
Chorionic villus sampling (CVS): This invasive but relatively painless test may be performed between 11 and 14 weeks to detect many genetic disorders. Your doctor may recommend this if you are 35 or over or have had an abnormal ultrasound, abnormal testing or a previous abnormal pregnancy. The test is performed by a limited number of specialists and involves removing chorionic villi cells from the placenta with a thin needle through the cervix or abdomen, using ultrasound as a guide. You should get rapid results within 72 hours and final results in 10 days. While the test is invasive, it has less than a one percent risk of miscarriage.
As you approach your second trimester, there are additional diagnostic tests you may consider, including amniocentesis and fetal echocardiography, that provide further information about your pregnancy. Should you have any questions about testing and live in the greater Las Vegas area, the doctors at the High Risk Pregnancy Center are always available to provide the information and guidance you need.