Pregnancy, Women Guide

Blood Counts in Pregnancy

A large or small blood count is one of the routine tests in pregnancy. The blood tests show that the mother and child are healthy and the pregnancy is normal.

The blood picture as part of the check-up

A large blood count is created during the three major antenatal checkups. The “smaller” preventive appointments every four weeks also include a small blood count. At the end of the pregnancy or when special risk factors are present, the blood tests can also be more frequent.

In addition to the standard evaluations, various pregnancy-specific examinations of the maternal blood are carried out. Blood levels of certain minerals and vitamins (iron, magnesiumfolic acid,…) are also measured. The documentation of the results of the blood tests is done in the maternal passport.

What is the difference between a small and a large blood picture?

With a small blood picture, the solid components of the blood are examined, in conjunction with a so-called differential blood picture to check the concentration and cellular nature of the white and red blood cells; this results in the large blood picture.

With a large blood count, the concentration of reticulocytes – the last precursor of red blood cells or erythrocytes – is also detectable. If present in large numbers, it indicates that the body is currently forming new erythrocytes to a greater extent. This can be an indicator that the body is about to overcome or develop a state of deficiency.

What values does the small blood count include?

A small blood count can be made from a few milliliters of blood. The doctor assesses the following values:


The hematocrit value describes the proportion of solid blood components in the whole blood. The higher it is, the worse the fluidity of the blood, which increases the risk of blood clots and thrombosis.


The erythrocytes (red blood cells) transport oxygen into all organs and tissues. An increased number of red blood cells is usually due to a lack of oxygen to compensate for the shortage. A reduced number of erythrocytes indicates blood loss or lack of care.

Hemoglobin (Hb)

The red blood pigment hemoglobin binds both oxygen and carbon dioxide in the blood.
The small blood count determines its total amount (HbE) as well as the amount of hemoglobin (MCH) bound to the erythrocytes. Too low a value almost always results in pregnancy from an iron deficiency.

Leukocytes (white blood cells)

The leucocytes are part of the body’s immune system; they destroy bacteria, viruses and other foreign structures. The leucocyte score indicates the overall condition of the immune system as well as inflammation and infection.

Platelets (platelets)

The number of platelets depends on the coagulation capacity of the blood. Pregnancy can cause the number of platelets to decrease or increase. At very low levels or the onset of other physical symptoms, the doctor will order further examinations to rule out pregnancy complications.

Special blood tests in pregnancy

As part of the initial examination, a small blood count is made, the blood type (A, B, AB or 0) is determined and the woman’s blood is tested for various properties important for the course of pregnancy:

Rh factor

About 15 percent of people do not have the rhesus factor; they are Rhesus (Rh) negative.
When an Rh-negative mother first expects an Rh-positive child and there is direct blood contact between mother and child, the mother develops antibodies against the baby’s blood. The antibodies may cause complications in a subsequent pregnancy if there is again a Rhesus intolerance.

Rh antibody screening

In Rh-negative mothers is already tested at the beginning of pregnancy, whether they have already trained rhesus antibodies. If he shows a negative result, from the 28th week of pregnancy and immediately after birth, prophylaxis with anti-D immunoglobulins. Also, the Rh antibody screening is repeated at the end of the second trimester of pregnancy.

Tests for antibodies against pathogens and infections

Primary infection with certain pathogens during pregnancy can be dangerous for the unborn child. As part of prenatal care, all women are screened for the presence of rubella antibodies. Also, there is a check for syphilis (Lues search test). These benefits are taken over by the health insurance funds as part of regular prenatal care. Default also offers all pregnant women an HIV test.

On the other hand, antibody tests for the detection of a previous infection with toxoplasmosis, listeriosis or cytomegalovirus are self-payable. They should also take place as soon as possible after the pregnancy becomes known.

Four to six weeks before the expected date of birth, the mother’s blood is examined for the presence of hepatitis B virus, in the case of a positive test result, the child is vaccinated immediately after birth.

Around the 24th week of pregnancy expectant mothers the so-called “oral glucose tolerance test” – the three times measurement of blood sugar levels within two hours after drinking a glucose solution – offered to detect gestational diabetes.

Blood tests in prenatal diagnostics

As part of the prenatal (prenatal), diagnostic blood tests are performed as part of the so-called first-trimester screening. The determination of the concentration of various proteins and hormones in maternal blood makes it possible to assess the statistical probability of genetic damage to the child.


  • A large or small blood count is one of the standard tests in pregnancy.
  • In addition to the standard examinations, various pregnancy-specific blood tests are performed (determination of the Rhesus factor, search for Rh antibodies, exclusion of infections).
  • As part of the first-trimester screening, special blood tests provide information about the statistical probability of genetic defects.

Leave a Comment

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.