During pregnancy, a lot of changes occur in the mother's body. To just give an example, the blood volume of the mother increases by one and a half litres and there are changes in the position of the heart, blood pressure, and pulse rate.
These are physiological changes. But there can also be some pathological alterations due to some underlying disease in the woman, which is not diagnosed or has become overt during the pregnancy.
These need to be investigated thoroughly as clinical examination alone may not be sufficient to detect them.
Hence, she needs to undergo some basic tests. Undergoing these tests also help ease the anxiety of most expectant moms, who keep worrying about the healthy progress of their pregnancy.
1. Haemogram for anaemia
As soon as a woman realises she is pregnant, it is important to get her blood haemoglobin level checked to rule out anaemia. Haemogram gives the complete blood count, which can give information about other parameters like the white cell count, platelet count and abnormalities if any.
The normal haemoglobin of a pre-pregnant woman should be 12g per cent. A haemoglobin count less than 10g per cent at the onset of pregnancy is anaemia and can cause several untoward consequences like growth restriction in the baby, infections in the mother, and dire changes in the cardiovascular system.
Nutritional anaemia is the commonest type of anaemia encountered. But some women may have other reasons to become anaemic such as thalassemia and sickle cell disease, which are further investigated if the haemoglobin level is found to be low or high.
Also, as the pregnancy progresses, blood gets diluted due to increase in its fluid content. The degree of this dilution needs to be assessed and therefore the test is repeated in the later months.
2. Sugar for diabetes
It is mandatory to screen pregnant women for diabetes. You could either do a random blood sugar level test or a test with oral glucose. This helps in identifying the disease, which can adversely affect the mother and the foetus.
3. TSH levels for thyroid
Thyroid screening [by checking your Thyroid Stimulating Hormone [TSH] levels] is essential because a thyroid abnormality can retard the growth of the baby.
If it comes positive, further thyroid evaluations are suggested to determine the exact cause of the abnormality as each type has a different affliction on the pregnancy outcome.
4. Serological tests for several diseases
Serological tests are done to screen for certain disease carrier states as they are known to cross the placental barriers and infect the foetus. The tests include VDRL for syphilis, Tridot test for HIV-AIDS and HBsAg for hepatitis B. These diseases are transmitted through close physical contact and therefore the father-to-be is also screened if the mother is found positive.
5. Rhesus factor for compatibility
It is essential to know the blood group of the mother. If a mother's blood group is negative, there is a possibility of developing problems during pregnancy.
Rhesus [Rh] antigen is an important antigen on the red blood cells, which determines the positive or the negative blood group of an individual. If the mother is Rh negative and the father is Rh positive, there is a 50 per cent chance of incompatibility in the pregnancy, which can result in anaemia and jaundice. Such a mother is periodically subjected to some tests such as the indirect Coomb's test, sonographic examinations, and colour Dopplers to determine the progress of the pregnancy.
6. Urine tests for infections
The urine is checked regularly for detecting infections and proteins. Presence of proteins in the urine indicates infection. Infections are common in pregnancy and can affect it adversely. Such infections can exacerbate and affect the urethras and the kidneys. Screening of this condition is therefore regularly done throughout the pregnancy.
7. TORCH and other tests
In addition, there are tests such as the first trimester screening and the triple tests for uncovering abnormalities in the foetus. In these, a combination of hormones and antigenic markers are checked from the blood sample and then graphically evaluated.
Some viral infections such as Toxoplasmosis, Rubella, Cytomegalovirus and Herpes [TORCH] are known to cross the placental barrier and cause adverse effects on the foetus. These infections are assessed by performing the TORCH tests.
The sound technology
Ultrasound examination [USG] is a non-invasive technique that uses sound waves. It does not involve any radiation and is harmless. USG in pregnancy, helps to assess the following:
- Location of pregnancy—inside or outside the uterus.
- Growth of the pregnancy—whether it corresponds to the derived duration.
- Signs of early stages of pregnancy, which cannot be clinically determined.
- The number of babies.
- The location of the placenta inside the uterus.
- Structural abnormalities in the baby.
- Biometric measurements of the baby to assess weight and growth restriction.
- The fluid around the baby.
- The blood flow in the various important blood vessels of the baby and the mother.
- The position of the baby.
USG examinations are done:
- In the first three months: to establish the correct baseline duration of the pregnancy.
- Between 18 – 24 weeks: To detect any structural abnormalities.
- 28 – 32 weeks: To assess the interim growth of the baby.
- 36-term: To assess foetal wellbeing and determine the biophysical profile.
In addition, the doctor may advise USG examination in situations where there are complaints such as pain, bleeding, and if s/he suspects growth restriction of the baby.
Advanced planning is key
The tests mentioned above are all basic screening tests. In situations when the mother-to-be is positive to a particular screening test or is clinically suspected to have a disease, further detailed evaluation is mandatory.
Ideally, a woman should visit a doctor even before she stops a contraceptive. The doctor can then properly evaluate her physical condition, order relevant tests [if necessary], recommend folic acid supplements and ensure a healthy pregnancy.
This was first published in the May 2011 issue of Complete Wellbeing.
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