What to Know About RhoGam Injections During Pregnancy

If you've given birth or experienced a pregnancy loss, and have a negative blood type, your healthcare provider may have recommended a RhoGAM injection. RhoGAM is the brand name for rho (D) immunoglobulin. It is a drug given to people with negative blood types during pregnancy or after a miscarriage to prevent the formation of antibodies to positive blood types.

RhoGAM is not the only brand of Rh immunoglobulin on the market, but it was the first developed, and the term became commonly used to refer to all Rh immunoglobulin.

What Is Rh Factor?

Rh factor is determined by the presence or absence of a certain protein on red blood cells. Those without the protein are Rh negative (so, A negative, B negative, and so on) and those with the protein are Rh positive (A positive, B positive, etc.).

Rh positive blood and Rh negative blood react to one another and result in the destruction of the blood cells. During pregnancy, a difference in Rh factor between parent and child can result in the parent's body producing antibodies that fight off the presence of the fetus.

What Are Rh Immunoglobulins?

Rh immunoglobulins prevent the pregnant parent's body from forming antibodies to Rh factor in the event that their baby's blood type is Rh-positive. Sensitization, or the formation of Rh antibodies, after a miscarriage is rare, but most physicians give Rh immunoglobulin to people with Rh-negative blood types as a precaution for future pregnancies.

Rh immunoglobulin is given by injection. It is a blood product and carries a very small risk of transmitting blood-borne viruses, but in the vast majority of cases, the benefits far outweigh the risks. Adverse effects attributable to RhoGAM are very rare; however, most physicians will keep people for observation for about 20 minutes following the injection.

Complications of Blood Type Mismatch

When an Rh-negative person gives birth to a baby with Rh-positive blood or miscarries a baby with Rh-positive blood, some blood from the baby can leak into the parent's circulatory system during delivery. During pregnancy, intermixing of blood occurs between parent and fetus as blood passes through the placenta.

With a blood type mismatch, called Rh incompatibility, this blood exposure can cause the parent's immune system to create antibodies to Rh-positive blood. In the case of future pregnancy, if the baby was Rh-positive, antibodies in the parent's body may then be primed to attack the fetus. This results in a blood condition called hemolytic disease of the newborn.

Symptoms

Hemolytic disease of the newborn is also called erythroblastosis fetalis. Infants born with this condition can appear in various states from normal to severely ill. This condition commonly presents as jaundice, or yellowing of the skin, eyes, and tongue, which occurs due to the breakdown of red blood cells by the liver and the accumulation of the blood cell byproduct bilirubin.

Hemolytic disease of the newborn can result in mild to severe anemia and can also cause cardiorespiratory arrest and death of the newborn baby.

Diagnosis

Hemolytic disease of the newborn can be detected either in the fetus or in the baby using laboratory tests. In order to diagnose the fetus, a cordocentesis must be performed at around 17 weeks gestation. Cordocentesis is an test in which blood is drawn from the umbilical vein in the umbilical cord, which connects to the placenta. Hemolytic disease of the newborn is diagnosed in newborns using blood testing.

Treatment

Treatment of newborns includes fluid support and feeding, light therapy to break down circulating bilirubin, intravenous immunoglobulin for the newborn, and supportive care. In severe cases, a blood transfusion might be necessary.

If the fetus is diagnosed in utero, treatment may begin before the baby is born. These types of treatments may include an intrauterine blood transfusion where blood is injected directly into the umbilical vein. Or, if the baby's lungs are fully developed, doctors may induce labor to deliver the baby early.

What Rho (D) Immunoglobulin Does

When a blood type mismatch is determined, a healthcare provider will recommend an injection of rho (D) immunoglobulin, commonly called RhoGAM. RhoGAM prevents the parent's body from developing antibodies that fight Rh-negative blood types.

One dose is given at the beginning of the third trimester, and a second is given within 72 hours of birth. RhoGAM is given as a shot and is generally well tolerated. Common side effects are pain at the injection site and low-grade fever.

Accurate blood typing and medical history are vital to ensure blood type mismatches aren't overlooked.

A Word From Verywell

With advances in modern medicine, hemolytic disease is becoming increasingly rare. Blood typing is part of most early pregnancy health checks and arrangements are made for pregnant parents to receive Rh immunoglobulin around the beginning of the third trimester. Regardless, potential complications can be scary, so don't hesitate to talk to your health care provider about your concerns.