Q & A With Dr. Uday Thanawala: The Necessary Tests At Different Stages Of Pregnancy

As you step into motherhood, your and your baby's health must be your first priority. Dr. Uday Thanawala, a leading obstetrician and gynaecologist, advises on the tests that must be taken at different stages of pregnancy.

Tests during the first trimester (first 12 weeks)

a. Haemoglobin (Hb), Complete Blood Count (CBC):

Having a low Hb and being anaemic in pregnancy is highly avoidable as your Hb should be above 11gm%. Being anaemic makes you lethargic. Less iron can adversely affect your baby too, since iron is needed for proper brain development of your child.
Blood count is done to make sure other blood parameters like platelets are normal.

b. Blood Sugar (Gestational Diabetes):

Do a 75 gms glucose challenge test. Irrespective of fasting (it is difficult to fast when you are pregnant), just take 75 gms of glucose with half a glass of water and give a blood sample for blood glucose exactly after 2 hours. Your blood sugar should be less than 140mg%.

c. Thyroid screen:

TSH (Thyroid Stimulating Hormone) is the test to be done and the value in the first trimester should be around or below 2.5.

d. Infection screen:

Infection status for HIV, Hepatitis B and C must be checked. We repeat these during pregnancy, even though they have been carried out before pregnancy. This is critical. If HIV or, HBsAg (Hepatitis B) is positive, there are measures available to treat so that transmission of infection from the mother to the child can be prevented timely.


e. Thalassemia status:

This can be done if the report is not known through a test prior to pregnancy.

f. Urine routine: 

Sometimes there are bacteria present in urine and cause harm to pregnancy.

At 11-12.4 weeks:

An ultrasonically is certainly recommended at this gestation to rule out defects in the fetus and to measure Nuchal Thickness (NT) (Skin fold behind the neck). This is a specialized scan and better to get it done from a reliable imaging center.

Screening for chromosomal anomalies like Down Syndrome-
A biochemical screening test known as a double marker is available and should be ideally done along with the NT scan described above.
Results of the NT scan, double marker test, age and weight are all fed into a computer software to give you your personalized risk of having a Downs baby.
If this comes as low risk, there is no need for further testing. If it comes as high risk, typically an invasive test like CVS (Chorionic Villus Sampling) is recommended.

At 16-20 weeks:

Screening for chromosomal defects – A triple marker or quadruple marker blood test can be offered, if double marker and NT scan not done earlier. Sensitivity is lesser than the results of the first trimester screening.

At 18-20 weeks:

Anomaly scan is a detailed scan of the foetus to rule out structural defects in the foetus.

At 24-26 weeks:

Blood tests need to be repeated – Hb, CBC – Blood volume increases thus, Hb can drop so must test again now.
75 Gram Glucose Challenge test – This test is a must now because a fair number develop gestational diabetes now. (Sugar could have been normal earlier). Routine Urine test follows.

32 weeks

Ultrasound Scanning – to monitor baby's growth
Bloods – Nowadays repeating Hb, CBC, Sugar and urine tests is recommended – However, still many take only Hb, if required. Sugar test is repeated, if some signs like extra amniotic fluid develops. 

36 weeks and beyond

Investigations are individualized. You may require further scans for monitoring growth, Amniotic fluid and blood flow (Doppler Studies) to the baby.
NST (Non-stress test) – a test to check baby's heart rate in response to movement may be ordered.


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Comments (23)

taruna lakshakar

mujhe aaj eomating krte tym achanak se kuchh chubha gale me or ab jal rha h pani bhi nhi piya ja rha mera11th week chl rha h koi darne ki bat to nhi h na

sapna gautam

mera 75 Gram Glucose Challenge test hua hai and meri sugar 2 hours 160mg aae hai greater than 140mg what should I do to control it. mujhe bhut tension ho gae hai please help me...
danger ki baat to nhi.... n me Kya karu..... mujhe kuch samjh nhi aa raha hai

Garima Singla

I wish I knew this before

Daniya William

very helpfull information. Thank u doctor

mounika yalamaddi

thank you for your information...


I wish I knew this before

Swaraa Tiwaari

Can Babychakra help me?


This is exactly what I was looking for.

lubna tabassum

This is just in time


This is exactly what I was looking for.

priya goyal

Hello sir.sir mera 10th week chl reha.daily spotting d prblm e bcz of low placenta.koi risk ?plz tell me muje kya krna chahiye?


I wish I knew this before

Nitu Thakur

This is so well written.

lubna tabassum

This is just in time


So informative.. thanks a lot


I wish I knew this before


This is exactly what I was looking for.


This is so well written.

anjali burnwal

I'm 33weeks pregnant mera hb 9.7 hai kya Karu koi problem to nhi hogi na?

Bishal jana

This is exactly what I was looking for. - Bang on!

jaseena Ghouse basha

This is so well written.

nimmi rathore


Priya karthick

This is just in time

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