List of screening tests during pregnancy, from trimester 1 to 3

Prenatal screening test or screening tests during pregnancy is a set of procedures performed during pregnancy to determine if the baby is likely to have certain birth defects or abnormalities. Most of these tests are non-invasive. These tests are usually done during the first and second trimester, but some are also done in the third trimester.

Screening tests during pregnancy can only tell you the risk or possibility of certain conditions in the fetus. If the screening test result is positive, more diagnostic tests will be needed to get a more accurate result. Here are some screening tests that are routine procedures for pregnant women.

Screening test in 1st trimester of pregnancy

The first trimester screening test, which can be started as early as 10 weeks of gestation, is a combination of an ultrasound of the fetus and a maternal blood test.

1. Ultrasound

This test is done to determine the size and position of the baby. In addition, it also helps determine the risk of the fetus experiencing birth defects by observing the structure of the baby's bones and organs.

Ultrasound nuchal translucency (NT) is a measurement of the increase or thickness of the fluid in the back of the fetal neck at 11-14 weeks of gestation by ultrasound. If there is more fluid than usual, it means there is a higher risk of Down syndrome in the baby.

2. Blood test

During the first trimester, two types of maternal blood serum tests are carried out, viz Pregnancy-associated plasma protein (PAPP-A) and the hormone hCG (Human chorionic gonadotropin). These are proteins and hormones produced by the placenta in early pregnancy. If the results are abnormal, there is an increased risk of chromosomal abnormalities.

Blood tests are also done to check for infectious diseases in babies, or what is called the TORCH test. This test is an acronym for five types of infectious infections, namely toxoplasmosis, other diseases (including HIV, syphilis and measles), rubella (German measles), cytomegalovirus, and herpes simplex.

In addition, a blood test will also be used to determine your blood type and Rh (rhesus), which determines your Rh relationship with the developing fetus.

3. Chorionic villus sampling

Chorionic villus sampling is an invasive screening test that is done by taking a small piece of the placenta. This test is usually done between the 10th and 12th week of pregnancy.

This test is usually a follow-up test of NT ultrasound and abnormal blood tests. This test is done to further confirm the presence of genetic disorders in the fetus such as Down syndrome.

Screening test in the 2nd trimester of pregnancy

1. Blood test

Blood tests during the second trimester of pregnancy include several so-called blood tests multiple markers . This test is done to determine the risk of birth defects or genetic abnormalities in the baby. This test is best done at weeks 16 to 18 of pregnancy.

These blood tests include:

• Alpha-fetoprotein (AFP) levels. This is a protein that is normally produced by the fetal liver and is present in the fluid that surrounds the fetus (amniotic fluid), and crosses the placenta into the mother's blood. Abnormal AFP levels may increase risks such as spina bifida, Down syndrome or other chromosomal abnormalities, defects in the fetal abdomen, and twins.
• The levels of hormones produced by the placenta include hCG, estriol, and inhibitors.

2. Blood sugar test

Blood sugar test is used to diagnose gestational diabetes. This is a condition that can develop during pregnancy. This condition can increase cesarean delivery because babies of mothers with gestational diabetes usually have a larger size.

This test can also be done after pregnancy if the woman has high blood sugar levels during pregnancy. Or if you have low blood sugar levels after giving birth.

This is a series of tests that are done after you drink a sweet liquid that contains sugar. If you are positive for gestational diabetes, you have a higher risk of diabetes in the next 10 years, and you should get tested again after pregnancy.

3. Amniocentesis

During amniocentesis, amniotic fluid is removed from the uterus for testing. It contains fetal cells with the same genetic makeup as an infant, as well as various chemicals produced by the baby's body. There are several types of amniocentesis.

Genetic amniocentesis test for genetic disorders, eg spina bifida. This test is usually done after the 15th week of pregnancy. This test is recommended if:

• Screening tests while pregnant show abnormal results.
• Have a chromosomal abnormality during a previous pregnancy.
• Pregnant women aged 35 years or more.
• Have a family history of certain genetic disorders.

3rd trimester of pregnancy screening test

Screening Strepococcus Group B

Strepococcus Group B (GBS) is a group of bacteria that can cause serious infections in pregnant women and newborns. GBS in healthy women is often found in the mouth, throat, digestive tract, and vagina.

GBS in the vagina is generally harmless to women regardless of whether they are pregnant or not. However, it can be very dangerous for newborns who do not yet have a strong immune system. GBS can cause serious infections in babies who are infected at birth. This test is done by rubbing the vagina and rectum of pregnant women at 35 to 37 weeks of gestation.

If the GBS screen is positive, you will be given antibiotics while in labor to reduce the risk of the baby developing GBS infection.

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