Negative Blood Group and Pregnancy Rh Incompatibility
Pregnancy and Trying to conceive

Negative Blood Group and Pregnancy Rh Incompatibility

Written by
Dr. Jimesh H Mavani
and medically reviewed by iCliniq medical review team.

07 Sep 2018  -  1 min read



This article gives a brief knowledge about Rh negative blood group and pregnancy complications, and preventions in simple terms.

What Is Rh Factor?

There are mainly four blood groups, namely A, B, O, and AB. There is a subtype of each as positive and negative blood groups, namely A +ve, A -ve, B +ve, B -ve, etc. The subtype gets decided by the Rh factor (rhesus), an antigen present on the red blood cells. When it is present, it is a positive blood group, whereas if it is absent, it is defined as a negative blood group.

In the general public, the absence of this antigen does not cause any issues. But, if an Rh-negative mother is carrying an Rh-positive baby, there is a need to take special care and treatment along with some precautions and preventive measures.

There is mixing of the mother's and baby's blood at some point in the pregnancy. So, when a mother is Rh negative, and the baby is Rh positive, then there is a chance of some complication if not in the same pregnancy, in the subsequent pregnancies.

Rh Incompatibility

When two different types of blood get mixed, out of which one is Rh positive, and the other one is Rh negative, then it is called as Rh incompatibility.

This is an important factor to consider during blood transfusion. In the context of pregnancy, when the mother’s blood group is Rh negative, and the fetus (baby growing in the womb) is Rh positive, then there is a chance of mixing of their blood during pregnancy or at the time of delivery which can lead to some serious complications. This is known as Rh incompatibility.

Pregnancy Complications Due to Rh Incompatibility

Most of the below complications happen during the second pregnancy, and the first pregnancy is spared from this.

  1. Abortion.
  2. Intrauterine death of the fetus.
  3. Anemia in the mother.
  4. Severe jaundice in baby on birth.
  5. Damaged liver and brain due to intrauterine anemia.
  6. Ascites.
  7. Generalized edema of the fetus.
  8. Low birth weight of the baby.

Precautions to Minimize Complications

  • Take enough rest. Do not push yourself hard.
  • Avoid lifting heavy objects.
  • Avoid sexual intercourse during pregnancy.
  • Consult your doctor regularly.
  • Take your medicines as per your doctor's instructions.


Once sensitization (mixing) occurs in the mother or when one pregnancy is affected, then the prognosis will get worse as the number of pregnancy increases.

Prevention of Complications

  • If you have a negative blood group and are planning to have a baby, then visit your doctor to know more about the precautions to undertake beforehand.
  • If pregnancy is positive, then start the treatment as early as possible.
  • If you notice any bleeding while pregnant, immediately consult your doctor.
  • If the husband's blood group is positive, then there is a high chance of the baby being Rh positive.

To know more about this unique pregnancy and negative blood group consult an Obstetrician & Gynaecologist online -->

Last reviewed at:
07 Sep 2018  -  1 min read



Related Questions & Answers

Rh was given as 'weak D positive'. Does that affect mother or baby?
Query: Hi doctor, My wife is pregnant for the first time and it is her 12th week. We did a blood grouping and urine culture testing last week. It is found that the blood group is 'O' but the Rh was given as 'weak D positive'. We did a second opinion testing in a different lab and the result was the same. ...  Read Full »
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Answer: Hello, Welcome to Weak D in itself is a specific category of blood group. Weak D expression primarily results from single point mutations in RhD which encode amino acid changes predicted to be intracellular or in the transmembrane regions of RhD. Molecular RhD blood group typing is ve...  Read Full »
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Answer: Hi, Welcome to Rh incompatibility is a mismatch that occurs between the blood of the mother and the blood of the fetus. It happens when the mother is Rh-negative, and the fetus is Rh-positive. When Rh-negative blood is exposed to Rh-positive blood, the Rh-negative blood responds by pr...  Read Full »
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Answer: Hello, Welcome to There is no harm in marrying a girl with the same blood group as you. Everyone is born with a certain blood type that is either Rh positive or Rh negative. Rh-positive blood is more common than Rh-negative. There is no problem if you marry a partner with the same blo...  Read Full »
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