If you are already sensitized, treatment can help protect your baby. Who gets Rh sensitization during pregnancy? If the mother is Rh-negative and the father is Rh-positive, there is a good chance the baby will have Rh-positive blood. Rh sensitization can occur.
If both parents have Rh-negative blood, the baby will have Rh-negative blood. Since the mother's blood and the baby's blood match, sensitization will not occur. How is Rh sensitization diagnosed?
If you have Rh-negative blood but are not sensitized: The blood test may be repeated between 24 and 28 weeks of pregnancy. If the test still shows that you are not sensitized, you probably will not need another antibody test until delivery. You might need to have the test again if you have an amniocentesis, if your pregnancy goes beyond 40 weeks, or if you have a problem such as placenta abruptio , which could cause bleeding in the uterus.
Your baby will have a blood test at birth. If the newborn has Rh-positive blood, you will have an antibody test to see if you were sensitized during late pregnancy or childbirth. If you are Rh-sensitized, your doctor will watch your pregnancy carefully. You may have: Regular blood tests, to check the level of antibodies in your blood.
Doppler ultrasound , to check blood flow to the baby's brain. This can show anemia and how severe it is. Amniocentesis after 15 weeks, to check the baby's blood type and Rh factor and to look for problems.
How is Rh sensitization prevented? You may get a shot of Rh immune globulin: If you have a test such as an amniocentesis. Around week 28 of your pregnancy. After delivery if your newborn is Rh-positive. The shots won't work if you are already Rh-sensitized. How is it treated?
Treatment of the baby is based on how severe the loss of red blood cells anemia is. If the baby's anemia is mild, you will just have more testing than usual while you are pregnant. The baby may not need any special treatment after birth. If anemia is getting worse, it may be safest to deliver the baby early. After delivery, some babies need a blood transfusion or treatment for jaundice.
For severe anemia, a baby can have a blood transfusion while still in the uterus. This can help keep the baby healthy until he or she is mature enough to be delivered. You may have an early C-section , and the baby may need to have another blood transfusion right after birth. Cause Rh sensitization can occur when a person with Rh-negative blood is exposed to Rh-positive blood.
Symptoms If you are already Rh-sensitized or become Rh-sensitized while pregnant, you will not have any unusual symptoms. What Happens If you are Rh-negative 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 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.
Mild Rh disease involves limited destruction of fetal red blood cells, possibly resulting in mild fetal anemia. The fetus can usually be carried to term and requires no special treatment but may have problems with jaundice after birth. Mild Rh disease is more likely to develop in the first pregnancy after sensitization has occurred.
Moderate Rh disease involves the destruction of larger numbers of fetal red blood cells. The fetus may develop an enlarged liver and may become moderately anemic. The fetus may need to be delivered before term and may require a blood transfusion before while in the uterus or after birth. A newborn with moderate Rh disease is watched closely for jaundice. Severe Rh disease fetal hydrops involves widespread destruction of fetal red blood cells.
The fetus develops severe anemia, liver and spleen enlargement, increased bilirubin levels, and fluid retention edema. The fetus may need one or more blood transfusions before birth. A fetus with severe Rh disease who survives the pregnancy may need a blood exchange. This procedure replaces most of the infant's blood with donor blood usually type O, Rh-negative. A history of pregnancy with Rh disease is a sign that you will need special treatment when you are pregnant with an Rh-positive fetus.
What Increases Your Risk Rh sensitization can occur when a person with Rh-negative blood is exposed to Rh-positive blood. Things that increase the risk of blood mixing and sensitization during pregnancy include: Delivery. Abdominal trauma, such as from a car accident. Abdominal surgery, such as a cesarean section. Placenta abruptio or placenta previa , both of which can cause placental bleeding.
External cephalic version for a breech fetus. Obstetric procedures such as amniocentesis , fetal blood sampling, or chorionic villus sampling CVS. Miscarriage spontaneous abortion , ectopic pregnancy , or elective abortion medical or surgical abortion after 8 weeks of fetal age when fetal blood cell production begins.
Partial molar pregnancy involving fetal growth beyond 8 weeks. When should you call your doctor? If you are already Rh-sensitized and are pregnant Your pregnancy will be closely monitored. If you are Rh-negative Call your doctor immediately if you: Think you may have been pregnant and miscarried. Are pregnant and have had an accident that may have injured your abdomen.
Who to see A woman who may have problems with Rh incompatibility or sensitization can be treated by: A family medicine doctor , for mild fetal Rh disease. An obstetrician , for mild to moderate Rh disease. A perinatologist , for moderate to severe fetal Rh disease hydrops. Exams and Tests If you are pregnant, you will have your first prenatal tests during your first trimester.
If you are Rh-negative and your partner is Rh-positive, your fetus is likely to be Rh-positive. If you are Rh-negative All pregnant women have an indirect Coombs test during early pregnancy. At the first prenatal visit, your blood is tested to see if you have been previously sensitized to Rh-positive blood. If you are Rh-negative and test results show that you are not sensitized, a repeat test may be done between 24 and 28 weeks.
If test results at 28 weeks show that you have not been sensitized, no additional tests for Rh-related problems are done until delivery barring complications such as placenta abruptio.
You will also have a shot of Rh immune globulin. This lowers your chances of being sensitized during the last weeks of your pregnancy. If your newborn is found to be Rh-positive, your blood will be screened again at delivery with an indirect Coombs test to see if you have been sensitized during late pregnancy or childbirth. If you have not been sensitized, you will have another shot of Rh immune globulin.
If you are sensitized to the Rh factor If you are already Rh-sensitized or become sensitized while pregnant, close monitoring is important to determine whether your fetus is being harmed. If possible, the father will be tested to see if the fetus could be Rh-positive. Rh disease is a dangerous kind of anemia.
The placenta grows in your uterus womb and supplies your baby with food and oxygen through the umbilical cord. This can happen if:. But if you get pregnant again, your body produces more antibodies that can cause Rh disease in your baby.
Rh disease can be prevented in your baby if you get treatment at the right times. Your provider watches your baby closely during pregnancy to check his health and for signs of anemia. In your third trimester, your provider may use amnio or a special ultrasound called Doppler to check your baby.
Ultrasound is a prenatal test that uses sound waves and a computer screen to show a picture of your baby inside the womb. If your baby has mild Rh disease, you may be able to have a full-term pregnancy. Full term means your baby is born between 39 weeks and 40 weeks, 6 days. After birth, your baby may need certain medicine, and she may need treatment for jaundice. Most babies recover fully from mild Rh disease.
If your baby develops severe Rh disease and severe anemia before birth, you may have to give birth early, before her due date. She may need a blood transfusion with new blood to replace red blood cells that the Rh antibodies destroyed. Babies can get a blood transfusion in the womb as early as 18 weeks of pregnancy; they also can get a transfusion after birth.
If your baby is born with severe jaundice, she needs quick treatment to prevent more serious complications. Get expert tips and resources from March of Dimes and CDC to increase your chance of having a healthy, fully-term pregnancy and baby. March of Dimes leads the fight for the health of all moms and babies. We support research, lead programs and provide education and advocacy so that every family can have the best possible start. Building on a successful year legacy, we support every pregnant person and every family.
March of Dimes, a not-for-profit, section c 3. Privacy, Terms, and Notices , Cookie Settings. These include:. Rh antibodies are harmless until the mother's second or later pregnancies.
If she is ever carrying another Rh-positive child, her Rh antibodies will recognize the Rh proteins on the surface of the baby's blood cells as foreign. Her antibodies will pass into the baby's bloodstream and attack those cells. This can make the baby's red blood cells swell and rupture. This is known as hemolytic or Rh disease of the newborn. It can make a baby's blood count get very low. If a pregnant woman has the potential to develop Rh incompatibility, doctors give her a series of two Rh immune-globulin shots during her first pregnancy.
She'll get:. Rh immune-globulin acts like a vaccine. It prevents the mother's body from making any Rh antibodies that could cause serious health problems in the newborn or affect a future pregnancy.
A woman also might get a dose of Rh immune-globulin if she has a miscarriage, an amniocentesis , or any bleeding during pregnancy.
If a doctor finds that a woman has already developed Rh antibodies, her pregnancy will be closely watched to make sure that those levels are not too high. In rare cases, if the incompatibility is severe and a baby is in danger, the baby can get special blood transfusions called exchange transfusions either before birth intrauterine fetal transfusions or after delivery.
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