Rh Factor Disease and Severe Anemia and Jaundice in Newborns

Everyone is born with either Rh-positive or Rh-negative blood. Most people are Rh-positive, which means they have the Rh Factor, a protein found on their red blood cells. Rh-negative people do not have this protein. Rh-positive blood is not compatible with Rh negative blood. If a pregnant woman has Rh-negative blood and the fetus has Rh-positive, there is a risk of the baby developing Rh disease.

What Causes Rh Disease in Babies? When a Rh-negative mom is pregnant with a Rh-positive baby, the baby's Rh-positive blood can pass into the mother's body during pregnancy or birth. When this happens, the mother becomes sensitized to the baby's incompatible Rh-positive blood and her body starts to produce Rh antibodies. These antibodies can pass through the placenta into the baby during pregnancy or birth, depending on when the sensitization occurs.

What Does Rh Disease Do to Babies? Once Rh antibodies from the mom have passed through to the baby, they can cause the rapid breakdown of the baby's red blood cells. This rapid breakdown of red blood cells can cause the baby to have severe anemia during pregnancy or after birth. Bilirubin is also made when the body breaks down red blood cells. The rapid breakdown of the baby's red blood cells causes a quick build up of bilirubin, causing severe jaundice usually within a day after birth.

Rh-negative moms can have babies with little to no problems in their first pregnancy because the baby is often born before the mother becomes sensitized to Rh-positive blood, or before her body produces a lot of Rh antibodies. Unfortunately, once the mother is sensitized, her body will produce Rh antibodies for the rest of her life. This means that later pregnancies are at greater risk for a baby developing Rh disease and/or for the disease to be more serious.

Can Rh Disease Be Prevented? Blood tests before or during pregnancy can show if a woman is Rh-negative and if she has been sensitized to Rh-positive blood and producing antibodies. If pregnant, Rh-negative, and not sensitized, the mother can be given shots of Rh immune globulin (RhIg) to prevent sensitization and therefore the development of antibodies. These shots are usually given around 28 weeks of pregnancy and within 72 hours after giving birth.

What if an Rh-Negative Mother Is Already Sensitized? If a pregnant woman is found to be Rh-negative and sensitized, blood tests are usually done to find out what the father's blood is. If the father is Rh-negative, then there is no risk of Rh-disease because the baby will have Rh-negative blood. If father is Rh-positive, there is a fifty percent chance that the baby will be Rh-positive. The next step is to find out if the baby is Rh-positive or negative. Sometimes, this can be done by blood tests from mom, otherwise an amniocentesis will be done.

Tests and Treatment. If the baby is Rh-negative, there is no risk of Rh Disease. If the baby is Rh-positive, blood tests are often done on the mother throughout the pregnancy to measure the amount of antibodies she is producing. If her body starts producing high amounts of antibodies, her health care provider will probably recommend tests to find out if the baby is developing Rh Disease. One of the ways this can be done is by monitoring for anemia (destruction of baby's red blood cells) through amniocentesis or doppler ultrasound throughout pregnancy.

If severe anemia from Rh Disease is detected in an early term baby through these or other tests, a blood transfusion through the umbilical cord may be done as early as eighteen weeks of pregnancy. If Rh Disease is suspected or detected in a near term baby, the health care provider may recommend inducing labor before any more of the baby's red blood cells are destroyed.

Once the baby is delivered, a blood test known as a Coombs Test can be done on the baby to see if the antibodies the mother's body made against the baby's red blood cells are present. A positive Coombs Test means the baby does have the antibodies that cause Rh Disease.

Depending on the seriousness of the effects of Rh Disease, the baby may be need to be treated for jaundice and/or have a blood transfusion for severe anemia, which will require the baby staying in the hospital.

If bilirubin levels are dangerously high, an exchange transfusion, replacement of baby's blood with fresh blood, may be done to remove some of the bilirubin that quickly built up. Phototherapy using special fluorescent lights is often done to break down bilirubin so it can be passed out of the baby through urine and bowel movements. There are also several other forms of treatment that may be used.

The goal is to get bilirubin levels to fall below a level of 10 and continue to drop for twenty-four hours. Blood tests are usually done frequently to check bilirubin and red blood cell count levels. The baby is usually allowed to go home once the baby's bilirubin levels stay below 10 without phototherapy.

Sometimes Rh Disease is so mild that the baby doesn't need any treatment.

Sources:

WrongDiagnosis.com - Hyperbilirubinemia

March of Dimes - Rh Disease

WebMD.com - Coombs Test