RhoGAM
The anti-D injection that stops an Rh-negative mother’s immune system from targeting an Rh-positive baby.
What RhoGAM does
If an Rh-negative mother’s blood meets her Rh-positive baby’s red cells, her immune system can make anti-D antibodies. Those antibodies can cross the placenta in a later pregnancy and destroy the baby’s red cells: haemolytic disease of the fetus and newborn (HDFN).
RhoGAM (Rh immune globulin) is ready-made anti-D. It binds the baby’s Rh-positive cells in the mother’s circulation so they’re cleared quietly, before her own immune system learns to recognise D. The injected antibody fades within weeks, which is why it’s repeated for each pregnancy and each sensitising event.
Before anti-D became routine in the late 1960s, Rh disease affected about 1 in 100 pregnancies in some countries and was a leading cause of stillbirth. Today it is rare where anti-D is available.
See the four steps play out, with and without anti-D, in the Rh factor explainer.
- Around 28 weeks
- Routine dose if the baby is or may be Rh positive
- Within 72 hours of birth
- If the newborn tests Rh positive; dose adjusted to the amount of fetal blood found (Kleihauer–Betke test)
- Bleeding in pregnancy
- Vaginal bleeding after 12 weeks, or any heavy bleeding
- Pregnancy loss
- Miscarriage, abortion, ectopic or molar pregnancy
- Procedures
- Amniocentesis, CVS, external cephalic version
- Abdominal trauma
- Falls, car accidents, blows to the abdomen
Based on ACOG and NICE guidance. Timing varies by country; follow your care team.
RhoGAM FAQs
What is RhoGAM?
RhoGAM is a brand of Rh immune globulin (anti-D): purified antibodies from donated plasma. Given to an Rh-negative mother, it clears any Rh-positive fetal red cells before her immune system can react to them.
When is RhoGAM given?
Routinely around 28 weeks of pregnancy, within 72 hours of the birth of an Rh-positive baby, and after events that may mix blood, such as bleeding, miscarriage, abortion, ectopic pregnancy, amniocentesis or abdominal injury.
Do I need RhoGAM if the father is Rh negative?
If paternity is certain and he is Rh negative, the baby will be Rh negative and anti-D is not needed. Many clinicians still offer it when paternity is uncertain; some services test the baby’s Rh type from the mother’s blood instead.
Is RhoGAM safe?
It has been used since 1968 and is considered very safe. Side effects are usually limited to soreness at the injection site; allergic reactions are rare. Because it is made from plasma, donors are screened and the product is treated to inactivate viruses.
Does RhoGAM help if I am already sensitised?
No. Once a mother has made her own anti-D, the injection cannot remove it. Instead the pregnancy is monitored closely for signs of fetal anaemia.