Prenatal tests during the first trimester would range from tests done on the mother’s blood samples and urine to the foetal screening. The tests would look for immunity towards certain diseases and infection in the mother, and also signs of any chromosomal disability in children. The screenings are typically done around the 11th week.
The below list gives a comprehensive list of the most common tests that a mother has to undergo during the first trimester:
- Blood tests and Rh factor test – This is done to assess the mother’s blood group (if not already known) and also to find the Rh element, a type of protein present in the surface of the red blood cells.
If an Rh negative mother is carrying a Rh positive baby, then there are chances that blood from the mother’s body would cross over to the placenta and cause harm to the baby.
- Complete Blood Count with ESR – This test will help in obtaining a complete account of different blood cells, and detect instances of underlying conditions like anaemia. ESR or erythrocyte sedimentation rate will also help in detecting some other inflammatory disease.
- Blood sugar test – Extremely important to detect if the mother is suffering from diabetes or not. Diabetes, when not in control, can cause pregnancy complications. The HbA1c shows the average blood sugar levels over the last three months.
- HbcAg – This test is needed to screen existence of hepatitis B virus. If the mother is tested positive with HBV, a lot of delivery care has to be ensured and the baby needs to be duly vaccinated actively and passively.
- TSH and FT4 – These tests are required to check prevalence of thyroid in expecting mothers. Free T4 is the measure of the T4 thyroid hormone in the mother’s body.
- Urine tests – One more routine test that is done to test the health of kidney, diabetes, urinary tracts, and bladder of the mother. Samples are collected to detect glucose and albumin.
- Tests for detecting sexually-transmitted infections – Tests for detecting HIV 1 and HIV 2 is done; herpes tests to detect the prevalence of Herpes 1 and Herpes 2, and a VDRL test for detecting the prevalence of syphilis is done.
- Double marker test – It is an important screening test undertaken to detect chromosomal abnormalities, especially if there is a suspicion that may arise sometime around the 12th week nuchal scan procedure, a sonographic pre-natal screening scan.
Apart from this, there are some more tests undertaken to detect other infections and diseases like rubella, toxoplasmosis, and cytomegalovirus. ICT and IgM torch test are also blood tests to detect Rh negative factor and also other blood-related infections.
There is also a first-trimester genetic test to screen for Down syndrome generally between the 11th and 14th week of pregnancy. Chorionic villus sampling for detecting sickle cell anaemia, cystic fibrosis, haemophilia, and muscular dystrophy, is also an invasive test that is prescribed especially if the expecting mother is more than 35.