Overview of Rh Incompatibility Screening

What Rh incompatibility is and how our North Florida OB/GYN specialists screen for it

Pregnancy is a magical thing, and delivering a healthy newborn is a miracle. But not all pregnancies don’t always go perfectly or smoothly. Pregnancy complications can affect the expectant mother, the unborn fetus, or both. One such complication is Rh incompatibility.

We’ll discuss more about this pregnancy complication below. In the meantime, if you have questions about your pregnancy journey, we invite you to contact the knowledgeable and compassionate North Florida obstetricians at All About Women.

What is Rh incompatibility?

Rh incompatibility, also known as Rhesus (Rh) disease, occurs when a woman has Rh-negative blood, but her baby has Rh-positive blood. Rh-negative blood contains no Rh factor, while Rh positive blood does. The Rh factor occurs as a covering of the red blood cells. If this coating is present on the cells, the person is considered Rh-positive. When a person’s blood cells have no such cover, the person’s blood has Rh-negative blood.

When is Rh incompatibility a problem?

Rh factors are genetic, meaning people get their Rh factor from their parents. It gets passed through your genes. The majority of individuals have Rh-positive blood. In general, your health isn’t affected by your Rh-factor. However, your blood’s Rh factor might cross from your baby into your bloodstream, causing your body to react as if the baby’s blood is a foreign substance.

If your body perceives your baby’s blood as a foreign substance, it will create antibodies against your baby’s blood. If you’re on your first pregnancy, antibodies shouldn’t develop or cause any issues during that pregnancy. But once the antibodies develop during a first pregnancy, they stay in your body. So, when a second baby comes along, you’ll most likely have problems during the pregnancy if your baby has Rh-positive blood.

If your body’s Rh-negative antibodies attack the baby’s positive Rh blood, the baby might develop hemolytic anemia. In hemolytic anemia, the baby’s red blood cells are destroyed faster than the baby’s body can replace them. The baby won’t get the oxygen needed from these red blood cells. Babies with significant or severe hemolytic anemia can even die from this condition.

Rh incompatibility signs and symptoms

Expectant mothers who are pregnant for the first time don’t typically have issues with Rh sensitivity and incompatibility. After the first pregnancy, however, an Rh-negative mother becomes sensitized to an Rh-positive baby.

Some of the symptoms of Rh incompatibility in a baby include:

Yellow amniotic fluid (During pregnancy, the amniotic fluid surrounding the baby will appear yellow due to bilirubin, which occurs when blood cells break down.)
Jaundice (The skin and the whites of the baby's eyes will appear yellower than average.)
Heart failure
Enlarged organs, otherwise known as hydrops fetalis (The baby’s stomach, scalp, liver, heart, spleen and lungs may swell.)
Pale skin because of anemia
Fast breathing
Fast heart rate
Swelling under the baby’s skin
Lethargy
Kernicterus (Kernicterus remains a severe state of too much bilirubin in the baby’s brain, which can cause brain damage, deafness, seizures, and death.)

If you’re an Rh-negative woman and have a baby with an Rh-positive man, your child remains at risk for Rh compatibility problems and hemolytic anemia. Your child has a 50 percent higher chance of having Rh-positive blood in this situation.

If you’re planning on becoming pregnant, talk to your doctor about having an Rh-factor screening test done to better understand your Rh factor status before becoming pregnant.

Treatment for Rh-negative factor

Rh immune globulin injections can be given to keep your body from producing Rh antibodies. If you discover that you have Rh incompatibility problems, you’ll need to receive these injections every time you have an Rh-positive baby. These injections remain both necessary and straightforward to keep you and your baby safe.

Another scenario that might expose you to Rh-positive blood during your pregnancy is miscarriages. If you get treated with Rh immune globulin immediately after a miscarriage, you won’t have Rh incompatibility during your next pregnancy.

If you’re looking to get pregnant, you should know whether you’re Rh-negative or not. Also, be sure to tell your healthcare providers so that they can recommend the right treatment for you.

How doctors screen for Rh incompatibility

If your healthcare provider suspects Rh incompatibility, he or she can run the following testing to ensure a proper diagnosis:

A test for Rh-positive antibodies in the mother
An ultrasound to view the baby for fluid build-up
Amniocentesis
Percutaneous umbilical cord sampling of the fetal blood (During this test, a blood sample gets taken from the baby’s umbilical cord. This sample gets tested for anemia, bilirubin, and other antibodies.)

Treatment for Rh factor incompatibility

Various treatment options for Rh incompatibility exist. Talk to your doctor about which type of treatment is right for you.

One treatment option is when a needle is placed through your uterus into your unborn baby’s abdomen, and then into an umbilical cord vein. The baby may get sedated to prevent movement during this procedure.

Another treatment possibility is early delivery. If the pregnancy becomes quite complicated, the best solution remains for the baby to be born. Once the unborn baby’s lungs have adequately matured, labor might get induced.

Thankfully, early testing and regular OB/GYN visits should keep both you and your baby healthy.