Screening for Pregnancy Risks Over Age 35
If you’re pregnant and over the age of 35, your doctor might recommend some additional testing. Know that some tests do have risks, and sometimes the tests can have a false positive results. Make sure you talk with your healthcare provider about the risks and benefits of each test so you can make the right decision for you and your baby. Here are some tests your doctor may suggest:
Ovarian Reserve Test
If you are over 35, your doctor may recommend an ovarian reserve test before you try to conceive. Your ovarian reserve refers to both the quantity and quality of oocytes (the cells in your ovaries) after the natural effects of aging. While the result does not show with certainty if conception will be difficult, it is a good indicator, and you may want to discuss potential fertility options with your health care provider.
Quad Marker Test
A quad marker test is performed between the 15th and 20th weeks of pregnancy. It is a blood test that measures substances that may show neural tube defects, like spina bifida, as well as genetic disorders such as Down Syndrome. This test can detect 80 percent of Down Syndrome risk in women over 35. Note that this test only indicates an increased risk, not a definitive diagnosis and there is a possibility for a false positive.
Specialized or Targeted Ultrasound
An ultrasound is an imaging technique that uses high-frequency sound waves to produce images of a baby in the uterus. Specialized or targeted ultrasound is looking for a suspected problem, such as abnormal development.
If your quad marker test is positive, your doctor may suggest an amniocentesis. A needle is inserted into the abdomen wall to remove a small amount of amniotic fluid, which is used to test the baby’s chromosomes and check for genetic diseases. These include chromosomal defects (e.g. Down Syndrome), Turner syndrome, sickle cell disease, cystic fibrosis, neural tube defects and more. While blood testing (quad marker test) indicates a risk, amniocentesis can give a diagnosis. Make sure you speak with your provider about the risks associated with amniocentesis before proceeding.
Chorionic Villi Sampling (CVS)
CVS can be performed earlier in the pregnancy and in place of amniocentesis. A doctor will place a needle through the vagina or abdomen to collect a small sample of cells, called chorionic villi. These are tiny parts of the placenta that have the same genes as your baby and can be used to check your baby’s chromosomes. Talk with your doctor about the risks associated with this test as well.
Cell-Free DNA Testing
Cell-free DNA testing is a blood test, much less invasive than amniocentesis or CVS, but it doesn’t have the precision of those tests. It has limited ability to identify all chromosome abnormalities (known as trisomies), but it can screen for common abnormalities, specifically trisomy 18 (life-threatening medical complications) and trisomy 21 (Down Syndrome), and can also test for sex chromosome composition.
Your healthcare provider is an excellent source of information about pregnancy over age 35. Share your questions and concerns with him or her so that you have peace of mind about this new phase of your life.