This causes Rh disease , which is dangerous for the fetus. Some Rh-negative people never become sensitized, even after exposure to large amounts of Rh-positive blood. The reason for this is not known. If you are already Rh-sensitized or become Rh-sensitized while pregnant, you will not have any unusual symptoms. Fetal problems from Rh sensitization are detected with Doppler ultrasound testing and sometimes with amniocentesis.

It is possible, though, that a fetus with severe Rh disease will move less frequently than it did earlier in the pregnancy. Other conditions with symptoms similar to Rh sensitization include other blood type incompatibility problems and fetal infections. Unless you are given Rh immune globulin just before or after a high-risk event, such as miscarriage, amniocentesis, abortion, ectopic pregnancy, or childbirth, you have a chance of becoming sensitized to an Rh-positive fetus's blood.

If you have been Rh-sensitized in the past, you must be closely watched during any pregnancy with an Rh-positive partner, because your fetus is more likely to have Rh-positive blood.

In response to an Rh-positive fetus, your immune system may quickly develop IgG antibodies, which can cross the placenta and destroy fetal red blood cells. Each subsequent pregnancy with an Rh-positive fetus may produce more serious problems for the fetus. The resulting fetal disease called Rh disease, hemolytic disease of the newborn , or erythroblastosis fetalis can be mild to severe. If you have been Rh-sensitized in the past, an Rh-negative fetus cannot trigger an immune reaction.

During pregnancy, an Rh-negative woman can become sensitized if she is carrying an Rh-positive fetus. Although rare, Rh sensitization has been known to occur after needle sharing between intravenous drug users.

Transfusing Rh-positive blood in an Rh-negative person can also trigger sensitization. But this is extremely rare, because blood is always tested prior to transfusion. Your pregnancy will be closely monitored. Discuss possible symptoms early in pregnancy with your doctor.

Repeated diagnostic testing will be needed to watch the fetus. Call your doctor immediately if you note a decrease in your fetus's movement after 24 to 26 weeks of pregnancy. A woman who may have problems with Rh incompatibility or sensitization can be treated by:. If you test positive for Rh sensitization, your health care system or health professional may want you to be followed and treated by a perinatologist or an obstetrician who can easily call in a perinatologist. If you are pregnant, you will have your first prenatal tests during your first trimester.

Every woman has her blood tested at the first prenatal visit to see what her blood type is. If your blood is Rh-negative, it will also be tested for antibodies to Rh-positive blood. If you have antibodies, that means that you have been sensitized to Rh-positive blood. The antibodies can now kill Rh-positive red blood cells. If you are pregnant or have miscarried, or if you have had an elective abortion, a partial molar pregnancy, or an ectopic pregnancy, you will need testing to see if you have been sensitized to Rh-positive blood.

All pregnant women have an indirect Coombs test during early pregnancy. If you are already Rh-sensitized or become sensitized while pregnant, close monitoring is important to determine whether your fetus is being harmed. If your blood is Rh-negative and you have been sensitized to Rh-positive blood, you now have antibodies to Rh-positive blood.

The antibodies kill Rh-positive red blood cells. If you become pregnant with an Rh-positive baby fetus , the antibodies can destroy your fetus's red blood cells. This can cause anemia. If you are already Rh-sensitized and are pregnant, your treatment will focus on preventing or minimizing fetal harm and on avoiding early preterm delivery.

If you are an Rh-negative woman and you have conceived with an Rh-negative partner, you are not at risk of Rh sensitization during pregnancy. Most health professionals treat all Rh-negative pregnant women as though the father might be Rh-positive. If you are already sensitized to the Rh factor, your pregnancy will need to be closely monitored to prevent fetal harm.

For more information on fetal and newborn treatment, see Treatment Overview. If you are unsensitized Rh-negative, treatment focuses on preventing Rh sensitization during pregnancy and childbirth. Rh immune globulin such as RhoGAM is a highly effective treatment for preventing sensitization.

Rh immune globulin is also needed within 72 hours after vaginal bleeding, a miscarriage, partial molar pregnancy, ectopic pregnancy, or abortion. Use of Rh immune globulin is effective in preventing Rh sensitization. Rh immune globulin contains Rh antibodies that have been purified from human donors. This treatment prevents an unsensitized Rh-negative mother from making antibodies against her fetus's Rh-positive blood.

If an affected fetus younger than 34 weeks needs to be delivered, corticosteroid medicine betamethasone or dexamethasone may be given to the mother to speed fetal lung development before a premature birth. An intrauterine fetal blood transfusion is sometimes used to supply healthy blood to a fetus with severe hemolytic disease of the newborn also called Rh disease or erythroblastosis fetalis.

A blood transfusion or exchange transfusion is sometimes given to a newborn to treat severe anemia or jaundice related to Rh disease. Author: Healthwise Staff. This information does not replace the advice of a doctor.

Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content. To learn more about Healthwise, visit Healthwise. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. Updated visitor guidelines. This can cause your baby to develop anemia , and in severe cases, result in miscarriage.

Since you and your baby don't share circulation, there are only a few points during pregnancy that fetal blood can come into contact with maternal blood. Tami Prince, M. To prevent complications, "it is critical that an Rh-negative woman be treated with Rh immunoglobulin if bleeding occurs in order to prevent antibody formation," Dr.

Prince says. Luckily, there's an injection women can receive during pregnancy to counteract Rh incompatibility: the RhoGAM injection. RhoGAM is an injection made up of antibodies called immunoglobulin that help protect a fetus from its mother's antibodies. According to the product website , "RhoGAM prevents the Rh-negative mother from making antibodies during her pregnancy. As long as the Rh-negative mother receives RhoGAM appropriately during every pregnancy, her babies are at very low risk of developing [anemia].

Sheila Chhutani, M. The RhoGam does not cross the placenta and will not harm the baby. This was 4 and a half months after my rhogam shot. I asked my dr if it was possible to still have the antibodies in my system from my last rhogam shot and perhaps those were the antibodies being picked up on the blood draw.

She didn't know and had me come back a month later for another blood draw to see if anything had changed. When I went home I googled and posted here but couldn't find much about how long the rhogam stays in your system, other than "about 3 months". So, I am NOT sensitized. Anyway, it just shows that the rhogam antibodies CAN stay in your system for as long as 4 and a half months.

Hope this helps someone! See all replies 2. Thank you for the update it was very very helpful! I was struggling and worrying because I miscarried May 23rd and had the Rhogam shot then. My doctor who had given me the shot in May said that I was still covered and just order a blood test to look at the ratio of antibodies.

After many messages from the other clinic I was so scared. I trusted my doctor but still having conflicting information was worrisome. I couldn't find much info on how long it stays in your system so your post really eased my mind. Why RhoGAM is used. Common side effects of RhoGAM. Risks of the RhoGAM shot — and not getting it.

Costs and options. The takeaway. Parenthood Pregnancy Pregnancy Complications. Second Trimester Pregnancy Complications. Read this next. Rh Incompatibility.

Medically reviewed by Debra Rose Wilson, Ph. Medically reviewed by Debra Sullivan, Ph. Medically reviewed by Fernando Mariz, MD.