Blood tests: why should they be done infants and during pregnancy?

Blood tests are easy, however extremely important. They answer lots of questions and allow to start an appropriate treatment. In case of pregnant women and infants, blood tests are particularly essential. Why is that? - we asked dr Beata Szymczyk-Hałas.

A lot of young moms ask themselves a question: how often should they test their kids' blood?

Beata Szymczyk-Hałas: Such tests aren't done routinely in case of infants. In order to receive a correct result, you have to draw 5-7 milliliters of blood at once - for such a small baby that is too much. Let's also add the pain, fear and extreme stress. If the history does not contain any abnormalities, there's no reason to put the baby through that. Unfortunately, there are situations in which blood tests are necessary. 

Such as?

It depends on the health issue what kind of test you have to do and how long it will take. Some of the indications for a blood test in a small child could be diseases of the mother during pregnancy, prematurity, low birth weight, growth disorders, improper feeding of the child. 

Are there any parameters in blood test results of the child which aberration isn't really a reason to worry?

We are talking about physiological lymphocytosis which is an increased number of lymphocytes in the blood smear (up to 70 percent). It stays that way from 3 months of child's life up to 4-6 years . In pediatrics there is a term called "physiological anemia of the first quarter" which occurs at 3 months of age and is characterized by a decrease in hemoglobin to 9-9,5 g/dl . Haematologists, in this case, recommend to conduct screening counts about at 12 months of age, unless there is a suspicion of anemia (then the control test is ordered in earlier).
Mówimy o fizjologicznej limfocytozie, czyli zwiększonej ilości limfocytów w rozmazie krwi (nawet do 70 proc.). Utrzymuje się ona od 3. miesiąca życia nawet do ukończenia 4-6 lat. W pediatrii funkcjonuje też termin ''fizjologiczna niedokrwistość pierwszego kwartału'', która występuje w 3. miesiącu życia i charakteryzuje się spadkiem wartości hemoglobiny do 9-9,5 g/dl. Hematolodzy w takiej sytuacji zalecają przeprowadzenie przesiewowego badania morfologii około 12. miesiąca życia, chyba że istnieje podejrzenie anemii (wówczas badanie kontrolne zleca się wcześniej).

Do such deviations also occur in case of pregnant women?

The only difference in case of women expecting a baby is a slightly reduced level of hemoglobin (up to 11-14 g/dl). Pregnancy does not affect any other parameters.
Seems like the number of blood tests that have to be done during pregnancy is big. Why is that?
All blood tests are performed for a reason, there's no randomness. During first gynecological exam (up to 10th week of pregnancy, between 7 and 8th week ideally), Polish Gynecology Society recommends compulsory tests. Some of them are: blood group with Rhesus and Immunoglobulins, full blood count, glucose and VDRL as well as other tests that allow us to detect viral diseases. 

How often should we do blood tests while pregnant?

Full blood count and urine examination should be done every month, but tests for infectious diseases - just once, unless the result is unambiguous or positive; then the test should be repeated.

Why is that so important?

I'll use  toxoplasmosis as an example, since in Poland congenital infections with this disease still occur. If a pregnant woman does not have antibodies against toxoplasmosis, it is recommended to repeat the test in subsequent trimesters. In case of an infection a quick  intervention by antibiotics is necessary, because it is the only way to protect the newborn against very dangerous complications. HIV is a similar story. Many women do not want to do this test, because they consider it unnecessary.

In our society there still is a stereotypical image of a HIV infected man as a person addicted to drugs or leading a rich sex life.

Exactly, and that's not true. The HIV virus does not rule out the possibility of being a mom, appropriate treatment and prevention gives 99 percent chance of having a healthy baby. Thus doctors recommend a test for determination of HIV in early pregnancy and at the end of it, because there were cases of infection with this virus during pregnancy.