The Rh factor may not be the predominant thing on your mind when you are pregnant. But it can be one of the factors that could affect your pregnancy, and hence must be a part of the discussion you have with your doctor. If you are wondering how the Rh factor can affect your pregnancy, read on.
Here, MomJunction explains the Rh factor, Rh incompatibility, effects of Rh incompatibility in pregnancy, and the preventive measures to take.
What Is Rh Factor?
The Rh factor is a type of protein found in the red blood cells. If your blood cells have the protein, then you are Rh positive. Otherwise, you are Rh negative. The Rh factor is passed through genes from the parents to the offspring (1).
If both the parents have Rh-negative blood, then the baby will be Rh negative. If the mother is Rh negative and the father is Rh positive, then it is possible for the fetus to be Rh positive (2). The latter condition, where the baby’s Rh factor is different from that of the mother, is termed as ‘Rh incompatibility’.
Should you worry if your baby is Rh positive and you are Rh negative? Keep reading to know.
Does Rh Incompatibility Affect Pregnancy?
Yes, there could be complications during the delivery, especially in the second pregnancy, if the mother is Rh negative and the fetus is Rh positive.
During delivery, when the Rh negative maternal blood comes in contact with the Rh positive fetal blood, the mother’s body mistakes the Rh protein to be a foreign substance and triggers the maternal blood to make anti-Rh antibodies to destroy the blood cells of the fetus.
This is referred to as the Rh disease and results in a neonatal condition called hemolytic disease (3). It can cause serious health problems in the fetus, including fetal mortality.
In the first pregnancy, it takes time for the Rh negative woman’s blood to make antibodies; therefore, it doesn’t affect the baby much. But an Rh-positive fetus in a second pregnancy is at a higher risk of being attacked by the antibodies that are created during the first delivery and already present in the mother’s blood.
Can You Develop Antibodies If The Pregnancy Is Not Carried To Term?
Yes, you can. If you have a miscarriage, induced abortion, or ectopic pregnancy, then the antibodies can develop in the blood. If the next pregnancy occurs before receiving the treatment, there are increased chances of risks to the fetus if it is Rh positive.
Next, we tell you what could increase the risk of Rh incompatibility during pregnancy.
What Are The Risk Factors For Rh Incompatibility?
Usually, the mother’s blood and fetal blood do not come into contact until delivery. However, their blood can get mixed up earlier due to:
- Amniocentesis or chorionic villus sampling (CVS)
- Attempts to manually turn the baby from a breech presentation before labor
- Trauma to the abdomen during pregnancy
- Bleeding during pregnancy
But how would you know when one of these leads to Rh incompatibility?
What Are The Symptoms Of Rh Incompatibility?
You may not experience any physical symptoms associated with Rh incompatibility. However, the baby can show the signs mentioned below (4).
- The amniotic fluid may turn yellow and contain bilirubin, which can be identified through amniocentesis.
- The ultrasound shows an enlarged spleen, liver, or heart, along with fluid build-up in the fetus’ abdomen.
- After birth, the infant may have low muscle tone or lethargy (5).
If not detected in time, the anti-Rh antibodies in the mother’s blood can affect your fetus’ well-being. Read on to know more about it.
How Does Rh Incompatibility Affect Your Baby?
Rh incompatibility can lead to various fetal and neonatal complications (6).
Complications in the fetus include:
- Anemia (severe anemia is associated with enlargement of the spleen and liver)
- Jaundice (yellowing of the eyes, skin, and the mucous membranes)
- Hydrops fetalis (fluid build-up in the fetal organs and tissues) (7))
Complications in the newborn include:
- Severe jaundice (the baby’s inability to handle a high quantity of bilirubin that results from the breakdown of the red blood cells).
- Kernicterus, a rare form of brain dysfunction due to excessive bilirubin. This is a form of severe jaundice that can also lead to deafness, brain damage, intellectual disabilities, and problems with vision and teeth (8).
There are different ways to diagnose Rh incompatibility during pregnancy, which we discuss next.
How Is Rh Incompatibility Diagnosed?
Detecting the Rh factor before or in early pregnancy is essential to reduce the associated pregnancy risks. The diagnostic procedures include:
- Testing the mother’s blood to determine the presence of Rh positive antibodies.
- Viewing the internal organs and tissues of the fetus through ultrasound to detect any fluid build-up or enlargement of the organs. It also assesses the blood flow through the vessels.
- Testing a sample of amniotic fluid via amniocentesis.
- Sampling a small amount of fetal blood from the umbilical cord using methods like percutaneous umbilical blood sampling to check for anemia and the presence of bilirubin and antibodies in the blood.
If this condition is diagnosed in the early stages of pregnancy, then the doctor might prescribe a treatment to reduce the risk to the fetus
What Is The Treatment For Rh Incompatibility?
The treatment methods for the baby with Rh incompatibility include (2):
- Intrauterine blood transfusion involves transfusion of red blood cells into the baby’s blood vessels. This is done by placing a needle through the uterus and the abdominal cavity of the fetus or into the vein of the umbilical cord. This method needs to be repeated even after the baby is born. This aims at preventing heart failure due to anemia in the fetus and enabling healthy fetal growth inside the womb (9).
- If the fetus develops any complication, then the doctor might suggest an early delivery. If the fetus has matured lungs, then labor induction is considered to prevent worsening of the condition.
The doctor will suggest the ideal treatment based on:
- Your overall health during pregnancy and medical history
- The extent of the problem
- Your tolerance towards specific procedures, medications, or therapies
- Your expectations from the treatment
- Your consent or preference
Another way to deal with the Rh incompatibility is to try and prevent it.
Can Rh Incompatibility Be Prevented?
Yes. Rh incompatibility can be prevented by stopping the production of Rh-negative antibodies in the maternal blood.
A blood test early during pregnancy can help determine if the mother-to-be is Rh negative. The test will also check for any Rh antibody titres. Accordingly, a medication called Rh immunoglobulin (RhIg) is given to her to stop the production of Rh antibodies. This is done in the following situations (1):
- At around 28th and 34th week of pregnancy (10)
- After the baby is born; the drug is administered within 72 hours of delivery to minimize the mother’s chances of developing Rh antibodies in six months of delivery and also in future pregnancies (11).
- After a miscarriage, abortion, or an ectopic pregnancy
- After carrying out invasive procedures such as CVS, amniocentesis, or fetal blood sampling
- Bleeding during pregnancy
- Trauma to the abdomen during pregnancy
- Manually turning a fetus from a breech presentation
With the medical advancements, the risk of Rh incompatibility has been mitigated to a great extent. If you are planning a pregnancy, make sure to get your blood checked and get the first-hand treatment to rule out any complications during pregnancy.
Do you have a related experience to share? Let us know about it in the comments section below.
2. Rh Sensitization During Pregnancy; University of Wisconsin Hospitals and Clinics Authority
3. Hemolytic Disease of the Newborn; UCSF Children’s Hospital, Stanford Children’s Health (2019)
4. Rh Disease; University of Rochester Medical Center Rochester, NY
5. Rh incompatibility; NIH
6. Hemolytic disease of the newborn; NCBI
7. Hydrops fetalis; NIH
8. What are Jaundice and Kernicterus?; Centers for Disease Control and Prevention (2018)
9. Intrauterine Transfusion; Texas Children’s Hospital
10. Rh Sensitization During Pregnancy; University of Wisconsin Hospitals and Clinics Authority (2019)
11. RhD negative blood type in pregnancy; State of Queensland