What Is Pre-Natal Screening?

As the name suggests, pre-natal screening tests are procedures which are conducted during pregnancy. The main aim of these non-invasive prenatal tests is to know whether your baby is healthy or may run the risk of suffering from any birth defects. During prenatal visits, your doctor will conduct a physical examination and also suggest a few routine tests to ensure that all is well with you and your baby.

In the first few visits, our doctors will conduct the following pre-natal tests:

A Urine Test

This will be tested to confirm your pregnancy. During your subsequent visits, your doctor will keep asking you for a urine sample, to check if you may be suffering from any urinary tract infections or other conditions.
A Blood Test

This will be tested to map your blood grouping and typing and help determine if you are suffering from any deficiencies for which supplements need to be prescribed. Also, a blood test will be able to determine if you have any sexually transmitted diseases, like Syphilis or Hepatitis B, as some of these can be transmitted to your baby. In such cases, your doctor will also advise you on different forms of treatment that can reduce the chances of passing on this ailment to your child.
An Ultrasound

This will be conducted to give an indicative idea about your delivery date, as well as whether you are expecting twins or triplets.

What Are Trimester-based Tests?

Your doctor, during the first, second and third trimester of your pregnancy, will suggest that you go in for a set of prenatal diagnosis tests.

First Trimester Screening Tests The First Trimester Fetal Diagnosis Tests include:
- Early Blood Tests – Two types of prenatal blood tests are conducted – serum integrated screening and sequential integrated screening test. The purpose of these tests is to measure the levels of substances in the blood, namely the plasma protein A, which is pregnancy-associated. Also, your doctor will use the blood test to rule out any genetic ailments like cystic fibrosis, sickle cell disease and thalassemia, among others.
- Ultrasound – Prenatal ultrasound tests offer you an image of the baby in the uterus. The main aim of ultrasound is to help you know the position of the baby, to find any potential abnormalities, to help you know how far the baby has come and so on.
Second Trimester Screening Test The Second Trimester prenatal diagnosis tests majorly include:
- Blood tests – During the second trimester, a quad marker screening test is performed. The main aim of this test is to know whether there is any sign of birth defects like Down syndrome.
- Glucose Screening– This prenatal test typically checks for any gestational diabetes. It is a condition which happens during pregnancy and is temporary. This type of problem could lead to the mother having a caesarian delivery.
Third Trimester Screening Test The third-trimester screening test includes:
- Group B testing – It is majorly performed during the 34-36 week. Your healthcare provider will swab your rectum and vagina. The samples would be sent to a lab to look for any bacteria. If the group B strep test is negative, no action is required. In case the group B strep test is positive, antibiotics are given during labour to prevent group B strep disease in your baby.
- Bio-Physical Profile (BPP) – This, essentially, is a test that is a combination of both non-stress and ultrasound. This late pregnancy test helps you to know how the is baby doing.