Question

Assertion: The disease erythroblastosis feotalis can be avoided in second pregnancy if Rh negative maternal blood exposed to Rh positive foetal blood during delivery of first child. Reason: If mother is administered with anti Rh antibodies immediately after the delivery of first child.

Short answer

The Assertion and Reason are correct, and the Reason is a correct explanation of the Assertion. The administration of anti-Rh antibodies to an Rh negative mother following delivery of an Rh positive child prevents the maternal immune system from recognizing the Rh positive cells as a foreign threat, thus avoiding the disease erythroblastosis fetalis in future pregnancies

Step-by-step solution

Understand Rh factor

The Rh factor is an antigen that exists on the surface of red blood cells in most people. People are divided into Rh negative and Rh positive, based on the presence or absence of the antigen. An Rh negative person does not have the Rh antigen, and this may cause problems in pregnancy.

Understand erythroblastosis fetalis

When an Rh negative woman is pregnant with an Rh positive fetus, there are no problems during the first pregnancy. However, if she is exposed to the Rh antigen during delivery, her immune system may recognize it as a threat and produce anti-Rh antibodies. Hence, if she gets pregnant again with an Rh positive fetus, these antibodies may cross the placenta and attack the fetus' red blood cells, leading to erythroblastosis fetalis.

Explain prevention

To prevent the formation of anti-Rh antibodies, Rh negative women are administered anti-Rh antibodies immediately after the first delivery. This prevents the Rh negative mother's immune system from recognizing the rh positive baby's cells as a threat and hence stops the immune system from creating anti-Rh antibodies.

Assertion and Reason Verification

Based on our understanding, we can say that the assertion and reason are correct. The disease erythroblastosis feotalis can be avoided in a second pregnancy if Rh negative maternal blood exposed to Rh positive fetal blood during the delivery of the first child was followed by an immediate administration of anti Rh antibodies.

Key concepts

Rh factor

The Rh factor is a protein found on the surface of red blood cells. It's an antigen that plays a significant role in blood transfusions and in pregnancy. Most people have this protein and are classified as Rh positive. However, some people—about 15% of the Caucasian population and a lower percentage in other racial groups—do not have the Rh factor and are thus Rh negative.

When an Rh negative person receives blood from an Rh positive donor, their immune system may react by producing antibodies against the Rh factor, considering it a foreign substance. Similarly, during pregnancy, an Rh negative mother carrying an Rh positive baby can develop antibodies against the baby's blood if their bloodstreams come into contact. It's essential to identify an individual's Rh status early in pregnancy or before a blood transfusion to prevent complications.

Rh incompatibility

Rh incompatibility occurs when an Rh negative individual is exposed to Rh positive blood. This is most commonly discussed in the context of pregnancy, where an Rh negative mother is carrying an Rh positive fetus. During pregnancy, the mother's and baby's bloodstreams do not typically mix. However, small amounts of fetal blood can cross into the maternal circulation during certain events like delivery, miscarriage, abortion, or some medical procedures.

In these circumstances, the mother's immune system may recognize the Rh positive cells as foreign and produce anti-Rh antibodies. Once these antibodies are made, the mother is considered 'Rh sensitized.' The presence of these antibodies may not affect the first pregnancy, but they can cross the placenta in subsequent pregnancies, potentially causing harm to an Rh positive fetus.

Anti-Rh antibodies

Once an Rh negative person has been exposed to Rh positive blood, their immune system can start to produce anti-Rh antibodies. These are immune proteins specifically designed to target and destroy Rh positive red blood cells, which the body now sees as threats.

For pregnant Rh negative women, these antibodies can become problematic in future pregnancies with an Rh positive fetus. When these anti-Rh antibodies cross the placental barrier, they may attack the red blood cells of the Rh positive fetus, which can lead to hemolytic disease of the newborn, also known as erythroblastosis fetalis. The severity of this condition can range from mild anemia in the fetus to more severe problems such as jaundice, brain damage, or even fetal death.

Pregnancy complications

Erythroblastosis fetalis is one of the serious pregnancy complications that can result from Rh incompatibility. This can be effectively prevented if managed properly. If Rh incompatibility is detected during pregnancy, the Rh negative mother can receive anti-Rh immunoglobulin injections. This preventative treatment involves administering a solution that contains Rh antibodies, which destroy the Rh positive fetal red blood cells in the mother's bloodstream before her immune system has a chance to react and create antibodies.

The administration of anti-Rh antibodies is usually done at around the 28th week of pregnancy and within 72 hours after the birth of an Rh positive baby to an Rh negative mother. This intervention is crucial as it helps to prevent the mother's immune system from becoming sensitized, thereby preventing the attack on the red blood cells of future Rh positive babies.