This article is about the use of ultrasound to detect complication of Rh incompatibility during pregnancy. Rhesus disease develops when red blood cells which is Rh positive from a fetus enter the maternal circulation of an Rh negative mother. This circumstance commonly happens at the time when the mother delivers the baby, but it can also happen at other times during pregnancy, like for instance when there is a spontaneous miscarriage or abortion.
Blood cells are recognized as foreign to the immune system of the mother, antibodies are then formed to destroy them. The Rhesus factor is an indicator that may or may not be present on the surface of the red blood cells of an individual. When a woman has the Rh constituent in her blood, she is considered Rh positive. When she does not have the Rh factor, she is considered Rh negative. When a person who has Rh negative blood is exposed to Rh positive blood, the body of the individual does not recognize the Rh factor and considers it as foreign. The body then builds antibodies against it as it would for any foreign substance that enters its system.
If the person who is Rh negative is ever exposed in the future to Rh positive blood, his or her body is armed to destroy the red blood cells that have the Rh factor. Troubles may happen if a woman with Rh negative blood conceives a fetus who has Rh positive blood. This may arise if the father of the baby has Rh positive blood. The body of the mother can become sensitive to the Rh factor and build up antibodies to attack the Rh factor.
The build up of antibodies does not usually occur until after the pregnant woman has delivered the fetus. However, not all women develop antibodies to the Rh factor after having one baby with Rh positive blood. Normally, there is no effect on the first born baby. If problems occur, they usually arise in second and later pregnancies. In the following pregnancy, these antibodies can cross the placenta and cause anemia or low blood count in the developing fetus. Rhesus immune globulin is given routinely for seven months in pregnancy and after delivery in Rh negative mothers. Although 99 percent effective in preventing Rh disease, reports from the 1990s indicate that 1 to 6 infants per 1,000 live births have evidence of the effects of Rh disease. Pregnant women with an antibody concentration of greater than 1:16 are monitored with serial ultra sounds and amniocenteses to measure possible destruction of fetal blood. In some cases, the fetus can be given red blood cells while still in the womb, this is done through an intrauterine transfusion.
Nowadays, there is a great way of detecting severe anemia to the baby even before the mother delivers the fetus. Through the use of a doppler ultrasound test, complication of Rh disease can now be detected early and proper treatment can be administered at the earliest time possible thus preventing further fatal complications. Before this procedure was discovered, to be effective in detecting anemia in Rh disease, the mother has to undergo several invasive procedures like amniocentesis just to keep tract of the health of the fetus. Now, we can effectively detect fetal anemia with a non invasive procedure, saving the mother from the risk of miscarriage or premature labor that comes from repeated amniocentesis.
In order to diagnose anemia in fetus through the use of a Doppler ultrasound, physicians measure the blood flow through the brain of the fetus inside the womb. It can be diagnosed that the baby has severe anemia when the baby has a less viscous blood that move faster through the brain. By monitoring the health of the fetus in the womb, doctors can intervene with blood transfusions for the baby if the anemia of the fetus gets severe. Now there is a better way and a more accurate test with a lesser risk to both the mother and the baby.
