Our radiologists in Ottawa routinely perform prenatal genetic screening tests for pregnant people to gain insight into the development of a fetus and determine whether serious conditions may be present. Today, we list the tests and explain the benefits of each.
Prenatal Genetic Screening Tests
As a pregnant person, you can opt for prenatal genetic screening tests to gain insight into the development of a fetus. Keep in mind that the results can also lead to some difficult, very personal choices such as whether to continue the pregnancy if it’s found that your baby likely has a serious condition.
Knowing this information may help prospective parents prepare for the birth of a baby that will require special care.
In addition, people attempting to get pregnant can take a test to investigate issues with fertility and gain insight into why they may be having difficulty conceiving.
No matter which choices you make, our radiology team at Premier Imaging will explain your prenatal screening options and help you navigate the process.
Two Types of Blood Tests
The two main types of blood tests include:
Standard Prenatal Blood Testing - This test measures chemicals in blood that can indicate relative likelihood of abnormalities.
DNA Detection Test - More recently, tests that can detect a baby’s DNA in a mother’s blood have hit the market.
Anyone who has prenatal genetic screening done should be aware that these tests cannot definitively detect whether an abnormality exists — they only estimate chances. If you receive an abnormal test result, further testing may need to be completed to confirm a diagnosis or to reassure parents about the condition.
Which prenatal genetic screening tests should I get?
Depending on how far along you are in your pregnancy and which tests your OB-GYN and medical team think may be useful, you may be referred to us for a couple of different types of tests, including:
Before Pregnancy
Saline Infusion & Tubal Patency
Saline infusion sonography (SIS) allows us to investigate problems with fertility, assess tubal patency in infertile patients and evaluate the size and position of the cervix and uterine cavity. A tubal patency study can assist in helping to identify why a woman may be having difficulty conceiving.
Your OB-GYN may also recommend SIS if your ultrasound results are abnormal, if you have had two or more consecutive miscarriages or are encountering a number of other circumstances. This test should be done between days 4 and 10 of your menstrual cycle. At this time, the endometrium will be at its thinnest and the secretory phase of your cycle will not cause any physiologic changes.
First Trimester
FTS Testing
A first-trimester screening test (also known as a first-trimester combined test) determines whether your baby may be at risk for specific chromosomal conditions such as Down Syndrome or Edwards Syndrome (trisomy 18).
The test can be taken earlier than many other prenatal screening tests and can offer a beneficial assessment of viability, anatomy and growth. An FTS test enables you and your healthcare team time to make informed, proactive decisions earlier in the pregnancy.
Throughout Pregnancy
Obstetrical Ultrasound
Depending on your specific health needs and your unborn baby’s needs, your doctor may send you for multiple obstetrical ultrasounds throughout your pregnancy. Women will often receive recommendations for one of these exams every trimester (three in total).
An obstetrical ultrasound captures images of a fetus or embryo in a pregnant person’s womb. This safe, painless test not only helps us to confirm pregnancy but to estimate how long a woman has been pregnant, and determine whether there are multiples.
Anatomy, growth and development of the fetus can also be assessed. If congenital or chromosomal abnormalities are present, they may be detected with this test.
Third Trimester
3D Ultrasound
If your OB-GYN or other specialists have a specific medical concern that needs more in-depth assessment, they will often order a 3D ultrasound to gain insight into fetal development issues.
Multiple two-dimensional images are taken at numerous angles and pieced together to create a three-dimensional rendering that’s easy for your medical team to understand and evaluate.
Detailed images of a fetus, both internally and externally are captured to find out whether congenital defects such as heart issues or skeletal abnormalities may be present. These may not appear on a standard ultrasound. Fetal heart rate can also be detected in real-time.
Through every phase of your pregnancy, prenatal genetic screening can potentially offer early indications of issues that may occur during the development of a fetus. While follow-up testing is needed to further assess any abnormalities that are discovered, these optional tests can yield valuable information.
