The Rh Factor and Your Pregnancy
Information About Pregnancy Protection
The Rh Factor and When It Is Important
The Rh factor is one of many blood group antigens found
on the surface of red blood cells. If you have this antigen you are considered
Rh positive. If you don't, then you are considered Rh negative. Everyone is
either Rh positive or Rh negative. One type is neither better nor worse than
the other, only different.
Your Rh factor is important if you are an Rh negative
woman and you become pregnant, or if you receive a blood trans fusion.
How the Rh Factor Can Affect Your Future
If you have Rh negative blood, there are two situations
that can affect you:
1. If the father of your baby is Rh positive, the baby
will probably be Rh positive too. An Rh negative woman carrying an Rh positive
baby may have an immune reaction if some of the baby's Rh positive blood cells enter
This immune reaction, called isoimmunization, means your
body's defense system recognizes Rh positive blood as foreign from your own and
produces “antibodies” to destroy the invading Rh positive blood cells.
The passage of blood from the baby to the mother's
bloodstream happens most often at delivery, but can also occur during
miscarriage, the termination of pregnancy, amnio centesis (test performed to
determine fetal health), or due to an injury or trauma. It is important to note
that a small number of women develop antibodies to Rh positive blood cells
during pregnancy for no apparent reason.
Antibodies to Rh positive blood may not be a problem in
first pregnancies; however, the antibodies stay in your blood stream, ready to
attack invading Rh positive blood cells, for many years to come. This can lead
to problems in future pregnancies by causing miscarriage or a disease known as
hemolytic disease of the newborn.
Babies born to Rh positive mothers, regardless of the
father's blood type, will usually be free of the dangers of hemolytic disease.
2. Someday it may become necessary for you to receive a
blood transfusion. If Rh positive antibodies already reside in your bloodstream
due to isoimmunization and the blood you receive is Rh positive due to error or
lifesaving reasons, your Rh positive antibodies will become mobilized and de
stroy the donor Rh positive cells. As a result, the transfusion could be
unsuccessful and possibly harmful to you.
Hemolytic Disease of the Newborn: A Threat to Your
When an Rh negative woman has Rh positive antibodies in
her blood and the baby she is carrying is Rh positive, the antibod ies could
possibly enter the baby's bloodstream, attack the baby's red blood cells and cause
hemolytic disease of the new born. At birth, the infant suffering from
hemolytic disease may be jaundiced and anemic or suffer permanent damage of the
brain and central nervous system which may result in mental retardation,
hearing loss, or cerebral palsy. Extensive medi cal care can be required,
including an exchange transfusion, in which all of the baby's blood is
replaced. This usually stops the destruction of the baby's red blood cells and
gives the infant a chance to survive.
The risk of hemolytic disease of the newborn is slight
with the first baby, but increases with each successive pregnancy.
Preventing Hemolytic Disease
HyperRHO® S/D, Rho(D) Immune Globulin (Human) can pre
vent hemolytic disease of the newborn, provided Rh positive antibodies do not
already reside in your bloodstream.
HyperRHO S/D is a specially prepared gamma globulin with
a high level of preformed antibodies against Rh positive blood cells. The
injection of HyperRHO S/D destroys any Rh positive blood cells that may have
entered the mother's bloodstream and prevents the mother's immune system from
producing Rh positive antibodies; thus protecting the baby from developing
HyperRHO S/D Full Dose — When Prescribed
Pregnancy and Other Obstetric Conditions Pertaining to
Rh Negative Women
HyperRHO S/D Full Dose is administered during pregnancy
if you fall into a high-risk category. For example, you are at risk of
producing Rh positive antibodies if you have an amniocentesis procedure
performed, or if you have a miscarriage or other termination of pregnancy at or
beyond 13 weeks' gestation.
Laboratory findings have shown that some Rh negative
women develop Rh positive antibodies during the last weeks of pregnancy even
without an antibody-stimulating event. As a preventive measure, your physician
will probably recommend the first injection of HyperRHO S/D Full Dose at the
28th week of pregnancy.
In both of the above situations, if the blood type of the
father or baby can be determined to be Rh negative, an injection of HyperRHO S/D
is not required.
Another injection of HyperRHO S/D Full Dose is
administered within 72 hours of delivery of an Rh positive baby.
HyperRHO S/D Full Dose may be used to prevent
isoimmunization in Rh negative individuals who have been transfused with Rh
positive red blood cells or blood components containing red blood cells.
HyperRHO S/D Mini-Dose — When Prescribed
A single dose of HyperRHO S/D Mini-Dose may be prescribed
for an Rh negative woman instead of HyperRHO S/D Full Dose in the event of
miscarriage or other termination of pregnancy occurring prior to 13 weeks' gestation.
HyperRHO S/D Mini-Dose is not required if the blood type of the father or fetus
can be determined to be Rh negative.
Will You Need HyperRHO S/D Again?
HyperRHO S/D provides protection only if you have not
already produced Rh positive antibodies. Women who have developed antibodies
through previous pregnancy, miscarriage, other ter mination of pregnancy, or
blood transfusion cannot be protected by HyperRHO S/D. This is why with each
pregnancy it is important to have
HyperRHO S/D injections within the prescribed time
Reactions to HyperRHO S/D
You may feel a temporary soreness at the site of the
injection. You may also have a slight and temporary change in body tem
perature. In very rare instances, an allergic type of reaction can occur, for
which your physician will take appropriate measures.
Delivering a Sound, Healthy Baby
Your physician can answer any questions you may have
about receiving a HyperRHO S/D injection to prevent hemolytic disease of the
newborn. If you know that you are Rh negative and you are pregnant, you should discuss
your situation with your phy sician. Today, with HyperRHO S/D, hemolytic
disease of the newborn can be reduced to its lowest possible rate of incidence.
Grifols Therapeutics Inc., Research Triangle Park, NC
27709 USA 08941120, U.S. License No. 1871 (Rev. September 2012)
Development of Hemolytic Disease
1. Rh positive (+) father. Rh negative (-) mother.
2. Pregnancy: Rh– mother is carrying Rh+ baby.
3. The passage of Rh+ blood from the baby to the mother's
bloodstream happens most often at delivery, but can also occur during
miscarriage, other termination of pregnancy, amniocentesis, or due to injury or
4. Rh+ antibodies stay in your blood stream, ready to
attack invading Rh+ blood cells, for many years to come.
5. Next pregnancy, mother's Rh+ anti bodies enter baby's
Rh+ bloodstream, attacking baby's blood cells and caus ing hemolytic disease of