Table of ContentsView AllTable of ContentsImportanceTimingSide EffectsSafetyFAQs

Table of ContentsView All

View All

Table of Contents

Importance

Timing

Side Effects

Safety

FAQs

RhoGAM is a shot given to pregnant people whose blood isnegative for Rhesus factor (Rh) proteinbut who are carrying an Rh-positive fetus.

This incompatibility can cause a pregnant person’s immune system to react to the Rh protein on the fetus’s red blood cells that have entered their bloodstream. This potentially causes complications like fetal brain damage and pregnancy loss in future pregnancies. RhoGAM almost completely prevents this.

RhoGAM contains Rho(D) immune globulin, which are antibodies specific to the Rh protein.These antibodies coat the Rh protein on any fetal blood cells that have entered the pregnant person’s bloodstream. This and other mechanisms prevent the pregnant person’s immune system from reacting to fetal Rh protein and developing their own antibodies, which could endanger a future pregnancy.

Read on to learn more about exactly why the RhoGAM shot is so important in cases of Rh incompatibility, when it’s given, and potential side effects.

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Doctor holding medication in the syringe, preparing for injection for a pregnant woman during a medical procedure in the clinic, close-up view

Importance of RhoGAM

If a person who is Rh-negative is pregnant with an Rh-positive fetus, there is a risk that if the parent’s blood comes into contact with the fetus’s blood, the parent could develop antibodies that attack Rh-positive red blood cells.

These antibodies could cause harm to an Rh-positive fetus, such as:

Because it takes time to develop antibodies, these effects are not usually seen in the first Rh-positive pregnancy, but may cause harm to any Rh-positive fetuses in the future.

The pregnant parent should have theirblood type, including Rh factor, tested and antibody screening done if indicated as part of early prenatal care. The fetus’s blood type is not routinely tested.

Rh factor is inherited in an autosomal dominant pattern, meaning it will be expressed whether a person has one or two copies of the gene, and there is no difference in expression in people of any sex. If both genetic parents are Rh-negative, their children will be, too.

If the sperm-contributing parent is Rh-positive and the egg-contributing parent is Rh-negative, there is a risk that their children will be Rh-positive.

If the pregnant parent is Rh-negative and their antibody screen is negative, a RhoGAM shot will be given if the other genetic parent is Rh-positive or if their Rh-factor is unknown.In cases where an Rh-negative pregnant person is not a genetic parent of the fetus, they will be given RhoGAM if either genetic parent is Rh-positive or their Rh-factors are unknown.

RhoGAM is considered safe to give to pregnant people. Millions of doses have been given to Rh-negative people who are or were pregnant and have never been shown to harm the fetus.

When Is RhoGAM Given?

The chance of parent and fetal blood mixing is highest at birth.But it can happen during the third trimester because of the growing placenta and thinning of the membranes that separate the parent’s blood and the fetus’s blood.

RhoGAM is given at around the 28th week of pregnancy.It is effective for about 13 weeks.

A RhoGAM shot should also be administered to an Rh-negative person within 72 hours after:

The fetus’s Rh type is usually not tested during pregnancy, as it can only be done using invasive procedures. If the pregnant parent is Rh-negative, the RhoGAM shot will be given during pregnancy if there is a possibility that the fetus is Rh-positive, without needing a confirmation.

Common Side Effects of RhoGAM

The most common side effects of RhoGAM are:

Allergic Reactions to RhoGAMAllergic reactions to RhoGAM are rare.Signs or symptoms of an allergic reaction include:Itchy rashTightness of the chestWheezingLow blood pressureAnaphylaxis(which may include swelling of the throat or tongue, shortness of breath, vomiting, lightheadedness, and/or hives)Wait at least 20 minutes to leave after receiving RhoGAM so you can be observed for a potential reaction.

Allergic Reactions to RhoGAM

Allergic reactions to RhoGAM are rare.Signs or symptoms of an allergic reaction include:Itchy rashTightness of the chestWheezingLow blood pressureAnaphylaxis(which may include swelling of the throat or tongue, shortness of breath, vomiting, lightheadedness, and/or hives)Wait at least 20 minutes to leave after receiving RhoGAM so you can be observed for a potential reaction.

Allergic reactions to RhoGAM are rare.

Signs or symptoms of an allergic reaction include:

Wait at least 20 minutes to leave after receiving RhoGAM so you can be observed for a potential reaction.

RhoGAM Safety

RhoGAM has been used since the 1960s and is considered very safe.

Because it is made from human blood, there is an extremely remote possibility of contracting ablood-borne infection. The measures taken to prevent this, including testing, makes this risk incredibly small. No one in the United States has gotten an infection from using RhoGAM since 1985.

The chances of developing Rh sensitization, and the risks to pregnancies that come with it, are much higher than the risk of potential problems from the RhoGAM injection.

RhoGAM and VaccinesSome vaccines (ones that contain live viruses) could be less effective when taken within three months of getting a RhoGAM shot. However, there is no evidence RhoGAM reduces the effectiveness of rubella vaccination after delivery, so this vaccine is still given when needed.Other vaccines are fineto take with RhoGAM. If you have had or will need a RhoGAM shot, talk to your healthcare provider about the timing of vaccines, including if you are planning on traveling out of the country.

RhoGAM and Vaccines

Some vaccines (ones that contain live viruses) could be less effective when taken within three months of getting a RhoGAM shot. However, there is no evidence RhoGAM reduces the effectiveness of rubella vaccination after delivery, so this vaccine is still given when needed.Other vaccines are fineto take with RhoGAM. If you have had or will need a RhoGAM shot, talk to your healthcare provider about the timing of vaccines, including if you are planning on traveling out of the country.

Some vaccines (ones that contain live viruses) could be less effective when taken within three months of getting a RhoGAM shot. However, there is no evidence RhoGAM reduces the effectiveness of rubella vaccination after delivery, so this vaccine is still given when needed.

Other vaccines are fineto take with RhoGAM. If you have had or will need a RhoGAM shot, talk to your healthcare provider about the timing of vaccines, including if you are planning on traveling out of the country.

Who Should Not Get a RhoGAM Shot?

People who should not get a RhoGAM shot include:

Summary

A RhoGAM shot should also be administered after any time an Rh-negative pregnant person may have come into contact with Rh-positive blood, such as with pregnancy loss, pregnancy termination, injury to the abdomen during pregnancy, or some forms of prenatal testing.

Complications and serious side effects from RhoGAM are rare, and the risks to future pregnancies from not getting the shot are greater than the risks of getting the shot.

Frequently Asked Questions

If a pregnant person is Rh-negative and their fetus is Rh-positive, the pregnant parent can be exposed to the fetus’s Rh-positive blood, causing antibodies to develop. These antibodies can then attack the fetus’s Rh-positive red blood cells.Future pregnanciesare also at risk if antibodies develop.

RhoGAM is a medication that contains antibodies against Rh factor protein. It stops the body from making its own antibodies against Rh-positive blood if apregnant parentis Rh-negative and is exposed to the blood of their Rh-positive fetus.

RhoGAM should also be given after any potential mixing of an Rh-negative pregnant parent’s blood and fetal blood, including after amiscarriage, pregnancy termination, some prenatal tests, or an injury to the abdomen during pregnancy.

When blood is typed, it is tested for both ABO and Rh types. These are two different blood type systems, which are inherited separately. A blood type is typically stated with its ABO type and its Rh type, such as A+, B-, O+, AB-, etc.Learn MoreBlood Types A, B, AB, O

When blood is typed, it is tested for both ABO and Rh types. These are two different blood type systems, which are inherited separately. A blood type is typically stated with its ABO type and its Rh type, such as A+, B-, O+, AB-, etc.

Learn MoreBlood Types A, B, AB, O

7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mount Sinai.Rh incompatibility.Kedrion Biopharma Inc.RhoGAM FAQs.MedlinePlus.Rh incompatibility.Children’s Hospital of Philadelphia.Blood types in pregnancy.American College of Obstetricians and Gynecologists.The Rh factor: how it can affect your pregnancy.American College of Nurse-Midwives.Rh-negative blood type in pregnancy.Journal of Midwifery & Women’s Health. 2020;65(1):185-186. doi:10.1111/jmwh.13086Centers for Disease Control and Prevention.General best practice guidance for immunization.

7 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Mount Sinai.Rh incompatibility.Kedrion Biopharma Inc.RhoGAM FAQs.MedlinePlus.Rh incompatibility.Children’s Hospital of Philadelphia.Blood types in pregnancy.American College of Obstetricians and Gynecologists.The Rh factor: how it can affect your pregnancy.American College of Nurse-Midwives.Rh-negative blood type in pregnancy.Journal of Midwifery & Women’s Health. 2020;65(1):185-186. doi:10.1111/jmwh.13086Centers for Disease Control and Prevention.General best practice guidance for immunization.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Mount Sinai.Rh incompatibility.Kedrion Biopharma Inc.RhoGAM FAQs.MedlinePlus.Rh incompatibility.Children’s Hospital of Philadelphia.Blood types in pregnancy.American College of Obstetricians and Gynecologists.The Rh factor: how it can affect your pregnancy.American College of Nurse-Midwives.Rh-negative blood type in pregnancy.Journal of Midwifery & Women’s Health. 2020;65(1):185-186. doi:10.1111/jmwh.13086Centers for Disease Control and Prevention.General best practice guidance for immunization.

Mount Sinai.Rh incompatibility.

Kedrion Biopharma Inc.RhoGAM FAQs.

MedlinePlus.Rh incompatibility.

Children’s Hospital of Philadelphia.Blood types in pregnancy.

American College of Obstetricians and Gynecologists.The Rh factor: how it can affect your pregnancy.

American College of Nurse-Midwives.Rh-negative blood type in pregnancy.Journal of Midwifery & Women’s Health. 2020;65(1):185-186. doi:10.1111/jmwh.13086

Centers for Disease Control and Prevention.General best practice guidance for immunization.

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