Prenatal Testing: 8 First Trimester Tests And Screenings You Need to Know About

Regular screening tests for each trimester are essential for prenatal care. You will be advised by your OB/GYN to take these tests, as they help track the progress of your pregnancy throughout the gestational period.

These tests are routinely performed and are quick, painless, and beneficial for both the mother and baby. In addition to this, your doctor may recommend some other special tests to determine developmental anomalies or other complications.

Here’s all that you need to know about the prenatal tests you will undergo during the first trimester of your pregnancy.

What Is Prenatal Testing?

Prenatal testing refers to the series of medical assessments that an expecting mum has to undergo throughout her gestational period. These tests include ultrasounds, blood tests, vaginal swabs, invasive and non-invasive genetic tests, and electronic fetal monitoring.

These routine tests help your doctor understand your and your baby’s health. Some of these tests are performed in every pregnancy. They analyse the baby’s development progress and check if you are in good health to hold the baby till delivery.

There are also other optional screening tests, which you can opt for, if you are at risk of some compilation. These optional tests help determine if your baby has any congenital disabilities or genetic abnormalities.

In case there are certain health conditions that run in your family, do ensure to mention them to your genetic counsellor. The specialist can help you identify if there are any possible birth defects that can have an impact on your or the child.

What Are The Different Types of Prenatal Testing?

There are two types of prenatal testing. They are categorised as:

• Diagnostic Tests: These tests help determine if your baby has a congenital disability or genetic condition. Diagnostic test results are 99% accurate. However, these tests may pose some risks for you and your baby.

• Screening Tests: These tests help identify the chances of having a baby with a chromosomal abnormality. Although screening tests don’t give definitive results, they have a set parameter that determines the outcome. 

If results are above or below a set measure, they are deemed positive for further testing. There are no risks involved in undergoing screening tests.

What Are The Routine Prenatal Tests Performed during Pregnancy?

There are certain prenatal tests that are commonly  performed during pregnancy:

• Urine Test: This test checks for bladder and kidney infections. It also helps identify conditions such as preeclampsia. 

• Blood Pressure Test: This test also helps to check for preeclampsia, which is a condition of high blood pressure.

• Blood Tests: These tests are done to find the Rh factor, thyroid function, blood type, and anaemia. It also helps reveal infections such as HIV, hepatitis B, hepatitis C, and syphilis.

In addition to these tests, the doctor will also determine your weight during every prenatal checkup to understand if your weight gain is ideal.

What Tests Are Necessary for The First Trimester?

The following is the list of tests performed in your first trimester, which is from week zero to week 13:

1. Blood Tests: The blood screening test checks for:

• Blood type
• hCG levels
• Possibility of sexually transmitted infections ( HIV, hepatitis B, hepatitis C, and syphilis.)
• Blood sugar levels
• Vitamin D deficiency
• Immunity to diseases such as chickenpox and measles
• Genetic risk for thalassemia, cystic fibrosis, spinal muscular dystrophy, and other diseases.

This test is done by collecting your blood sample using a syringe or needle and submitted to the lab for testing. There are no risks involved in this test, other than the discomfort of bruising and pricking from the injection.

2. Ultrasound: The first ultrasound is done between 6-9 weeks. It checks the estimated due date, rules out tubal or ectopic pregnancies, detects fetal heartbeat, and the number of fetuses. This test has very low risks involved.

3. Urine Tests: Urine tests are quick and have zero risks involved. They check for the following:

• High protein levels that indicate preeclampsia
• High blood sugar levels that indicate gestational diabetes
• Levels of white and red blood cells to determine urinary tract infections.

4. Pap Smear Test: This test detects the presence of any abnormal cells in the cervix. It helps reveal if there are any cervical abnormalities that aren’t visible to the naked eye. It also detects infections that might affect the outcome of the pregnancy. 

5. Chorionic villus Sampling: This test is performed between the 10th and 13th weeks to determine birth defects such as cystic fibrosis and Down syndrome. It is usually suggested for those with a greater risk of genetic disorders.
   
   For this test, a small sample of placenta cells is withdrawn. There are some risks involved in this test, but it is generally safe and reliable.

6. Rh Factor Testing: This test is vital for all pregnant women. If you test Rh-negative and the baby’s father tests Rh-positive, that would mean that your baby too has Rh-positive blood.  In this case, your body might consider the baby’s Rh factor as a foreign object and react by producing antibodies to fight the baby’s blood cells.
   
   Based on your doctor’s supervision, you will need a simple treatment plan that would protect you and the baby.

7. Non-invasive Prenatal Testing (NIPT): It is performed after 10 weeks and checks for chromosomal disorders such as Edwards syndrome, Patau syndrome, and Down syndrome. 
   
   The test uses your blood sample to look at cell-free DNA and detect abnormalities. Very low risks are involved in this test.

8. Nuchal Translucency Screening: This test is performed between 11-13 weeks of pregnancy and checks for Down syndrome. It uses a unique ultrasound to examine the possibility of a chromosomal defect.

Recommended Prenatal Tests For Women Over 35

Pregnant women over the age of 35 are usually recommended to undergo genetic screening tests. This is because the risk of chromosomal abnormalities increases with advancing age. The usual tests that your doctor may recommend include chorionic villus sampling, cell-free DNA testing, amniocentesis, anatomy ultrasound, and nuchal translucency screening. 

Always ensure to get your prenatal tests done on time as they help determine your and your child’s safety. Also remember, that the number of tests performed or the frequency of ultrasounds can vary from one woman to another, depending on their health condition.

Do consult your doctor for any other specific tests that you need.