First Trimester | First Trimester Screening Tests: What to Expect

In your first trimester of pregnancy, there is a lot going on with both your body and your life, but with regular appointments with your doctor all of these things can be much easier. One of the things your doctor may suggest is a series of first trimester tests, most of which are optional but recommended. They can show you what’s really going on with your baby, and we’ll take a look at some of them now.

Do You Really Need These Screening Tests?

Legally, no first trimester screening is required, but most moms-to-be want to know if their fetus is healthy and developing normally. Most of the tests are offered near the end of the first trimester -- usually between 10 and 14 weeks -- although some are given as early as nine weeks. If your pregnancy is an at-risk pregnancy or if you’re over the age of 35, the doctor will likely highly recommend that you take certain tests.

First trimester prenatal screening usually includes two basic tests. The first one is a basic blood test, which tests the DNA of the developing fetus. They simply draw blood from one of your veins and send the sample to a lab. The second test is a transvaginal ultrasound, in which a tiny transducer is inserted into the vagina to help them get more accurate results.

More Specific Testing Is Sometimes Conducted

Sometimes these tests are looking for general information, while other times they are conducted to look for something specific. For the blood test, two substances are looked for in the pregnant woman’s blood. The first is the level of pregnancy-related plasma protein-A (PAPP-A) in the placenta. If the number is too low, it might mean the baby is at risk for some type of chromosomal defect.

The second test looks for a hormone called the human chorionic gonadotropin (hCG). Much like PAPP-A, an abnormal number might mean the fetus is at risk for a chromosomal defect. Neither of these tests mean for certain that the fetus will have some type of abnormality. It just means they might be at risk of it.

There is also a test to determine if certain birth defects are likely. Many of these tests are done up to weeks 12 or 13 and test for defects such as Down syndrome (trisomy 21), Trisomy 13, or Trisomy 18. Some of these defects are incompatible with life, so it’s important to many expectant moms that they find this out as soon as possible.

There is also an ultrasound test for fetal nuchal translucency, or NT. The test involves looking at the back of the baby’s neck in case there’s thicker-than-normal skin or increased fluid in the area. If there is, it might mean a defect. Finally, there is cell-free fetal DNA screening. With this test, structural birth defects are not found but it is easier to find defects in the X or Y chromosomes, which are the sex chromosomes.

What Happens Next?

If you get any type of testing during one of your pregnancy checkups, it might mean that further testing is needed. These tests can sometimes cause false-positive results, and the doctor will want you to know for certain what your options are. First and foremost, you’ll want to ask yourself certain questions before getting any type of testing done.

These include the following questions:

• Will the results be perfect? Before you agree to any type of prenatal test, you’ll want to know the accuracy of each test and what the results mean. Check with your doctor to get the answer to this question.
• Am I prepared for the results of the test? If you end up with unexpected test results, you’ll have some serious decisions to make, so you need to be prepared for the outcome of the test regardless of what it is.
• Are there any risks with the test? These tests generally come with very few risks, but since this is your body that’s being affected, not to mention your baby’s, you’ll want to know exactly what the risks are with each test.

Once you agree to having the tests done, you’ll be meeting with a healthcare professional after they get the results. In that meeting, they’ll go over everything in detail and answer all of your questions. The test results may, in fact, affect your remaining prenatal care and might even make you change your course, but at least you and the doctor will both know that this is necessary.

If something is wrong with your child, you will have to decide whether or not to continue the pregnancy. If you decide to do just that, at least you’ll be more prepared to take care of the child once they arrive. You’ll have the rest of your pregnancy to research the baby’s condition and learn all you can about it so you can be a better parent to the child.

The bottom line is this: Only you can make the decision whether or not to get prenatal testing done. This is why it’s so important to ask lots of questions and check with your doctor before deciding for sure to have the testing done.

Conclusion

Prenatal testing is done mostly to check for certain birth defects, but the tests can create both false-positive and false-negative results, which means the doctor will likely want to do additional testing. Some of this additional testing is done later in the pregnancy, and you should feel comfortable getting all of the facts about the tests before you make a final decision.