Rh Sensitization During Pregnancy - Prevention
If you are Rh-negative and pregnant
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 the Treatment Overview section of this
If you are unsensitized
Rh-negative, treatment focuses on preventing Rh sensitization during pregnancy
Rh immune globulin (such as RhoGAM) is a highly effective treatment for
- To prevent sensitization from occurring late
in the pregnancy or during delivery, you must have a shot of Rh immune globulin
around week 28 of your pregnancy. This treatment prevents your immune system
antibodies against your fetus's Rh-positive red blood
- Rh immune globulin injection is also necessary if you have
had any vaginal bleeding or an obstetric procedure such as
external cephalic version.
- If your newborn
is Rh-positive, you are given Rh immune globulin again within 72 hours of
delivery. By preventing Rh sensitization from delivery, you are protecting your
next Rh-positive fetus.
- If your newborn is Rh-negative, sensitization cannot happen,
and no treatment is needed.
Rh immune globulin is also needed after a
partial molar pregnancy,
ectopic pregnancy, or abortion.