• About us

All about Rh Incompatibility

Answers to Your Most Common Questions About Blood Types, Pregnancy, and Newborn Health .Please connect with your doctor to better understand your Rh status and possible risks. Your doctor can guide you on the right tests, precautions, and care to ensure a safe pregnancy.

How does Rh Incompatibility develop?

Blood group incompatibility happens when the mother and baby’s blood are clashing: A, B, AB and O incompatibility do not cause major illnesses in the baby
Rh incompatibility is a result of : Mother being Rh negative (without Rh factor) and baby being Rh positive (with Rh factor) Such as when the mother is A-ve , B-ve, AB-ve or O-ve and the baby is either A+ve, B+ve, AB+ve or O+ve

What is Rh incompatibility in pregnant women?

When a woman with an Rh-negative blood group is pregnant with a baby who has an Rh-positive blood group, she may be exposed to Rh-positive blood during certain events, such as:

  • Bleeding at any time during pregnancy
  • Miscarriage or ectopic pregnancy (when the pregnancy occurs outside the uterus)
  • Medical procedures such as amniocentesis (a test where amniotic fluid is collected using a needle) during delivery

Once the mother is exposed to Rh-positive blood, her body may produce antibodies against the Rh antigen. This process is called Rh sensitisation, and these situations are known as sensitising events.

While the first baby is usually not significantly affected, problems can occur in subsequent pregnancies if the baby is Rh-positive. The antibodies formed in the earlier pregnancy can cross the placenta and attack the baby’s red blood cells (RBCs). This causes the red blood cells to break down, a process called hemolysis, which can lead to severe anemia, heart failure, and other serious complications in the baby.

All about Rh Incompatibility

Answers to Your Most Common Questions About Blood Types, Pregnancy, and Newborn Health . Please connect with your doctor to better understand your Rh status and possible risks. Your doctor can guide you on the right tests, precautions, and care to ensure a safe pregnancy.
Rh incompatibility occurs when a mother’s blood type is Rh-negative and the baby’s blood type is Rh-positive. The mother’s immune system may recognize the baby’s Rh-positive red blood cells as foreign and produce antibodies against them.
In India, about 5–7% of people are Rh-negative, while globally it’s around 7% . Rh incompatibility can therefore occur in a smaller but significant number of pregnancies.
Rh incompatibility usually becomes a concern when the mother is exposed to Rh-positive blood such as during delivery, miscarriage, abortion, ectopic pregnancy, or certain prenatal procedures. However, sometimes a small, unnoticed fetomaternal haemorrhage (silent transfer of baby’s blood into the mother’s circulation) can also trigger antibody formation.
If untreated, maternal antibodies can cross the placenta and destroy the baby’s red blood cells, causing hemolytic disease of the newborn (HDN) or erythroblastosis fetalis. This can lead to anemia, jaundice, heart failure, or even stillbirth in severe cases.
It’s detected through:
• Blood typing (to know Rh status)
• Indirect Coombs test (to check if the mother has developed Rh antibodies)
By giving an Rh immunoglobulin injection (RhIg or Anti Rho-D Immunoglobulin) to the Rh-negative mother:
• Around 28 weeks of pregnancy, and
• Within 72 hours after delivery of an Rh-positive baby.
Also after miscarriage, abortion, or invasive prenatal tests.