Important Tests During Every Trimester Of Pregnancy

During pregnancy, it is important to get certain medical tests done in every trimester. Here's what the expert says. 

Navya Kharbanda
Written by: Navya KharbandaUpdated at: Dec 02, 2022 17:35 IST
Important Tests During Every Trimester Of Pregnancy

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Pregnancy is a physiological condition. As you get pregnant, doctors are responsible for the health of the mother as well as the baby in your womb. Antenatal care is an important aspect of pregnancy. It is necessary to detect medical conditions and diseases affecting mother and/or baby as early as possible to reduce the mortality or morbidity associated with it. The objective of antenatal care is to achieve a normal pregnancy with delivery of a healthy baby to a healthy mother. Your doctor may recommend you multiple tests as a part of routine antenatal care. It is important to report to your gynaecologist as soon as you skip your menses and confirm your pregnancy.

It's also necessary to highlight the necessity of preconception counselling. Most of the couples who are thinking about getting pregnant are not aware of the benefits of meeting a gynaecologist before you start planning a baby. Women need to be in optimal health prior to planning a pregnancy. Preconception is a vital time to assess and identify various risks that could lead to adverse maternal and foetal outcomes. OnlyMyHealth editorial team spoke to Dr. Shreedevi Tanksale, Director - Obstetrics & Gynecology & Infertility specialist, Little Miracles Fertility Clinic, to know about the important tests that should be done during all the trimesters of pregnancy. 

Important tests during pregnancy: Trimester wise 

Most commonly performed blood tests include:

1. Complete blood count; Haemoglobin levels to detect anaemia

2. Blood group and Rh type

3. Blood sugar levels to detect Diabetes

4. Thyroid function test to detect thyroid dysfunction

5. Hb Electrophoresis to detect Thalassemia

The first visit to your gynaecologist is vital. It’s the time when you confirm that you're pregnant. Usually the gynaecologist will recommend an ultrasound. An early ultrasound (around five to seven weeks) is needed to:

• Confirm the pregnancy and give accurate timing of pregnancy. 

• Rule out ectopic pregnancy and miscarriage signs 

• Check other complications associated with early pregnancy like subchorionic collection 

• Detect number of foetus

Pregnancy is calculated in weeks from the last normal period date.

Also read: Stages Of Pregnancy: Here's The Baby Development, Symptoms And Self Care Tips For All Three Trimesters

First Trimester

At about six to seven weeks, gynaecologists will recommend blood tests as a part of initial screening. These tests include:

1. Complete blood count (CBC)

2. Blood type and Rh factor

3. Blood sugar levels - Fasting and Post Lunch

4. Urine analysis 

5. HIV antibody

6. Hepatitis B screening - HbsAg

7. Syphilis screening VDRL

8. Thyroid function test - TSH,T3,T4

9. Rubella antibody screening

Screening for genetic conditions

It consists of two tests that are done between 11-13 weeks of pregnancy:

1. Ultrasound test for foetal nuchal translucency (NT) and Nasal bone

An ultrasound is done to examine the part at the back of the foetal neck for extra fluid or thickening.

2. Maternal serum (blood) tests 

These tests measure two substances ( also known as DUAL MARKER ) found in the blood of all pregnant women:

A. Pregnancy-associated plasma protein screening (PAPP-A). 

B. Human chorionic gonadotropin (hCG). This hormone is made by the placenta in early pregnancy. 

If the results of these tests are abnormal, you may need more testing. Additional test that can be recommended is NIPT, to detect genetic abnormalities. However it is not recommended to all patients on routine basis.

Second Trimester

In addition to the Dual marker test, gynaecologists may recommend Triple or Quadruple marker as a part of screening for genetic abnormalities. The most important test in the second trimester would be an Ultrasound scan done between 18-20 weeks. Anomaly scan is done to: 

• To examine the foetal anatomy for abnormalities - detailed scan to check all the organ systems of the foetus

• To check the amount of amniotic fluid

• To examine blood flow patterns

• To measure the length of the cervix

• To monitor foetal growth 

Blood tests are done around 24 weeks for screening anaemia, diabetes and thyroid dysfunction. These tests include:

1. Complete blood count

2. Blood sugar levels - Fasting and post lunch

3. Glucose challenge test - single 75 gram oral glucose challenge test done between 24-28 weeks 

4. Urine analysis

5. Thyroid function test

Also read: Prenatal Tests That Every Woman Should Undergo Before Planning a Pregnancy

Third Trimester

Ultrasound scan to be done at 28, 32 and 36 weeks:

• To monitor foetal growth

• To check the blood flow pattern - Colour Doppler study

• To check the amount of amniotic fluid

• To determine the position of the foetus

• To assess the placenta

Blood tests are done around 36 weeks.

1. Complete blood count (CBC)

2. Blood sugar levels - Fasting and Post Lunch

3. Urine analysis 

4. HIV antibody

5. Hepatitis B screening- HbsAg and anti HCV

6. Essential tests that should be offered to all pregnant women:

Trimester Ultrasound Blood

1. Dating scan six to eight weeks

2. NT scan - 11-13 weeks 1. CBC

2. Blood type

3. Blood sugar levels

4. Thyroid function test

5. Urine analysis

6. Infection screening- HIV, HbsAg, VDRL

Second Anomaly scan 18-20 weeks CBC, Blood sugars, Thyroid test and urine analysis. Third Growth scan and Doppler at 32 weeks CBC, Blood sugars, Thyroid test, urine analysis and HIV, HbsAg, HCV. Remember that pregnancy is a precious gift and it is important to preserve it carefully. Few basic blood tests can help detect and prevent maternal and foetal complications.