Did My Miscarriage Happen Because I'm Rh Negative?

Why your Rh status may not be to blame

Female doctor taking blood sample of a pregnant woman
Glow Wellness/Glow/Getty Images

Women who know they are Rh negative often wonder if their Rh status played a role in their miscarriage. With this review, learn what Rh factor is and how it may affect a woman's chances of pregnancy loss.

What Is Rh Factor?

Just as people have blood types, they can also have an Rh factor, the protein often found on red blood cells. While most people do have the Rh factor, which is known as being RH positive, some people do not.

They are referred to as Rh negative.

Nature determines who is Rh positive and who is Rh negative. If both parents are Rh negative, their offspring will be as well. But if the mother is Rh-negative and the father is positive, the child may be either Rh positive or Rh negative, according to American Congress of Obstetricians and Gynecologists (ACOG).

The Link Between Rh and Miscarriage

It's normal to want to understand why a miscarriage happened, and it's frustrating that definitive answers are few and far between. After hearing about the need for RhoGAM after a miscarriage, many Rh negative women wonder whether that blood type might play a role in causing the miscarriages.

The short answer to that is no, being Rh negative in and of itself does not cause miscarriage or pregnancy loss. Women who are Rh negative, who have kept up to date with recommended RhoGAM shots and who do not have antibodies against Rh factor do not face increased risk for pregnancy loss due to having Rh negative blood.

Rh Factor and Stillbirth

Assuming a woman does become sensitized to Rh factor, however, the primary risk is not of pregnancy loss but of Rh incompatibility issues with any future baby to whom she gives birth.

In Rh-negative moms who are sensitized to Rh factor, there's also an increased risk of stillbirth due to a condition called immune hydrops fetalis that can develop in the second and third trimesters -- but this condition is not a factor in first-trimester miscarriages.

The most common cause of first-trimester miscarriages is chromosomal abnormalities in the baby.

Wrapping Up

If you are Rh negative and concerned that you might be sensitized to Rh factor, talk to your doctor about having a blood test done to check for anti-Rh antibodies. If the test comes back negative, then your Rh status will not bring any increased risks in a future pregnancy (but do continue to get RhoGAM shots per your doctor's recommendations).

Mothers who are sensitized to Rh factor should be vigilant about seeking prenatal care in any subsequent pregnancy.

While knowing that you've tested Rh negative may cause you to worry, especially if you've had a miscarriage, remember that miscarriages are incredibly common, and most women who've endured them are Rh positive, as is the general population. Moreover, many women who are Rh negative have gone on to have full-term pregnancies and healthy children. 

Talk to your doctor about your concerns over your Rh status as well as any other factors that could have potentially led to your pregnancy loss.


A.D.A.M. "Rh incompatibility."  A.D.A.M. Healthcare Center 18 Aug 2006. Accessed 27 Nov 2007.