HEMOLYTIC DISEASE
OF THE NEWBORN
Hemolytic disease of the newborn is caused
by the incompatibility between the blood of
the mother and her baby. In the case of the
Rh blood group system, most people have Rh-positive
blood, meaning that they produce the Rh factor,
an inherited protein found on the surface of
their blood cells. The others lack this Rh factor
and are considered Rh-negative.
An Rh-negative mother and an Rh-positive father
may conceive a baby who inherits the father's
Rh-positive blood type. There is then a danger
that, during pregnancy and especially during
labor and delivery, some of the fetus's Rh-positive
red blood cells may get into the mother's bloodstream.
Since red blood cells containing the Rh factor
are foreign to the mother's system, her body
tries to fight them off by producing antibodies
against them. This triggering of the mother's
immune response is referred to as "sensitization."
In a first pregnancy, there is very little
danger to an Rh-positive fetus because the baby
usually is born before the mother is sensitized,
or at least before the mother produces substantial
Rh antibodies. But, if sensitization occurs,
the woman will continue to produce antibodies
which may be present in her blood throughout
her life. In each later pregnancy, maternal
Rh antibodies can cross the placenta and reach
the fetus. Each subsequent baby becomes at greater
risk for more severe Rh disease. If the fetus
is Rh-positive, the mother's antibodies will
destroy fetal blood cells, resulting in Rh disease
for the baby.
To prevent Rh disease, all Rh-negative mothers
should receive an injection of Rh immune globulin,
which protects the fetus from antibodies from
its mother. This treatment works in the vast
majority of cases, but a few women cannot benefit
from it. |
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BRIDGET'S STORY
Bridget was born on May 5, 2005. Soon after her birth,
her doctor diagnosed her with Rh incompatibility disease.
This took everybody by surprise as Kim, her mother, had
given birth to two babies previously with no problems. She
had received Rh immune globulin shots for those births and
also had the shot for her pregnancy with Bridget.
It is not uncommon for newborn babies to have jaundice,
which is a yellow discoloration of the skin and the whites
of the eyes. It is caused by a build-up of a yellow pigment
in the blood called bilirubin. In most cases, jaundice goes
away without treatment, but in severe cases, it can pose
a risk of brain damage. Bridget showed signs of jaundice,
and her bilirubin numbers were somewhat elevated, so she
received treatment before going home.
Not long after Kim and her husband, Edward, had taken Bridget
home they noticed she was looking dramatically yellow. After
lab tests showed that her bilirubin level was dangerously
high, she was rushed back to the hospital. Her doctor, Igor
Gladstone MD, considered giving her a full blood exchange,
but instead decided to give her a transfusion of red blood
cells. She ended up having two transfusions. These transfusions,
along with other therapies for jaundice, showed immediate
results, and Bridget's numbers dropped to a far safer level.
Five days after receiving her life-saving transfusion, Bridget
went home again, this time for good. She is now a happy,
healthy baby who is gaining weight daily.
Bridget
receives phototherapy to treat her jaundice. This special
blue light helps to change the bilirubin in the blood
to a form that can be easily eliminated in urine. |
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