Tests During Pregnancy

• 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.

• 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%. High glucose load presented to the baby in antenatal period can result in big babies who cannot control their sugar after birth and worse these babies can become diabetic in adult life.

• 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. Thyroid hormone is important for neurological development of the baby.

• 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.

• Thalassemia status:

  This test is done to know your thalassemic status as a thalassemic minor status in both parents can lead to a thalassemic child.

• Urine routine:

  Sometimes there are bacteria present in urine and can complicate pregnancy.c

Test between 11 and 12.4 weeks of pregnancy:

• An ultrasound 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, further testing like NIPT is required.

Test between 16th and 20th week of pregnancy:

• 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.

Test between 18th and 20th week of pregnancy:

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

Test between 24th and 26th week of pregnancy:

• 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.

Test in 32nd week of pregnancy:

• Ultrasound Scanning – to monitor baby’s growth
• Blood tests – 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 develop.

Test after 36th week of pregnancy

• 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