What Prenatal Tests Are Done in The First Trimester

List of Important Prenatal Tests Done in the First Trimester

Prenatal tests done in the first trimester combine blood tests for routine testing, blood tests for genetic testing, and ultrasound scans. Each of these tests give the doctor different pieces of information regarding the health of the mother and the growing foetus. Geneitc testing plays a crucial role in the set of prenatal tests as it helps with the early identification of any possible chromosomal abnormalities.

Let us take a look at each of these tests in detail

1. Carrier Screening For Genetic Testing

According to NCBI, this is a type of genetic testing to check if there is any genetic disorder in your genes or not. This test involves testing a blood sample, saliva sample, or sample picked from the cheek to test for genetic disorders. Both parents must undergo this testing. Doctors may even suggest you to do this test when you are planning a pregnancy. The purpose of this test let you know if you have any chances of having a baby with a genetic disorder. If there is anything wrong with the test results, your doctor will give you genetic counselling according to your condition.

[Read : What Is Genetic Carrier Screening Test And How Is It Done?]

2. Cell-Free Fetal DNA Testing (NIPT)

A cell-free fetal DNA (cfDNA) test is done to rule out certain chromosome disorders like

• Down syndrome, which occurs when there is a trisomy or extra copy of chromosome 21.
• Edwards Syndrome, that happens due to the trisomy of chromosome 18.
• Patau syndrome, which happens due to the trisomy of chromosome 13.

As some of the unborn baby’s DNA circulates in the mother’s blood, cfDNA or NIPT blood test is done to predict any such syndrome. This test can be done any time after 10 weeks. There is no risk from cfDNA test for you and your baby. Your doctor can suggest this test if you or your spouse/partner are

• More than 35 years old.
• Have complications with other prenatal test results.
• Have a family history of chromosome disorders.
• Foetal ultrasound doesn’t look normal.

3. Chorionic Villus Sampling (CVS)

A cell-free DNA (cfDNA) test can detect a chromosomal disorder. But to know which type of Chromosome syndrome it is, the Chorionic Villus Sampling test will help. This test is done between 10 to 13 weeks of pregnancy. In this test, a sample of chorionic villi is taken from the placenta either through the cervix or through the abdominal wall. This test has a risk of miscarriage, so doctors only suggest this test when it is extremely necessary. For instance, when the test results will decide whether you should continue the pregnancy or not. Babies with conditions such as Down syndrome can survive but those with Edwards syndrome or Patau Syndrome will die within one year. In such cases, doctors may decide that the best course would be to terminate the pregnancy. In such cases, CVS testing may become imperative.

4. Early Ultrasound (First-Trimester Ultrasound)

One of the most necessary prenatal tests is the First-trimester ultrasound. In this test, sound waves are used to get images of the baby and its position in the uterus. It is a safe process and throughout your pregnancy, you will have to do USG multiple times. A first-trimester ultrasound aims to detect

• The expected date of delivery
• Pregnancy outside uterus
• Number of foetuses
• Growth, development, and heartbeat of the fetus
• Amount of amniotic fluid and the position of the placenta.

For the first trimester ultrasound, you will have to drink a lot of water and hold your pee before the test to get a better view of the uterus.

[Read : First Trimester Scans For Your Growing Baby]

5. Quadruple Test

As the name suggests, this test checks for the levels of four hormones in the mother’s blood. These hormones are Alpha-fetoprotein, HCG, Estriol, and Inhibin A. This test helps to determine the risk factors of carrying a baby with genetic defects such as Down syndrome, or Edwards syndrome, Anencephaly or Spina bifida.

6. Additional Tests

Other than the above, your doctor will also recommend some routine tests to check blood sugar, thyroid, HIV, ABO, and Rh factors during the first trimester. All these tests will keep your doctor informed of your general health condition so that they can take the necessary steps if something is amiss.

Prenatal testing must be an important part of the routine for all parents who are preparing to invite a new life into their lives. It helps you prepare for the best and the worst as well. Prenatal tests are vital to confirm your safe and secure pregnancy and a healthy baby. So, try not to miss them.

[Read : What Causes Anencephaly During Pregnancy?]

FAQ’S

1. Why Would a Pregnant Woman Have to Undergo Prenatal Testing?

Pregnant women must go through some prenatal tests to check whether their body is capable of the pregnancy, or if there is any abnormality, genetic disorders, birth defects, etc. Early detection can help the doctor identify the complications and help you decide on the next steps.

2. How Early in Pregnancy Can You Test For Birth Defects?

You can go for the first-trimester screening between 11 to 13 weeks of pregnancy. This will be the right time for your gynaecologist to monitor the progression of your pregnancy and identify the possibility of birth defects.

3. Does Prenatal Genetic Testing Detect the Gender of The Baby?

The NIPT test or non-invasive prenatal test can detect the gender of the baby. Since the chromosomes undergo testing, the gender also can be identified.

Read Also: What Prenatal Tests Are Done in the Second Trimester?