In: Biology
Women with the Rhesus negative serotype are routinely given a dose of Rh immunoglobulin (RHOGAM) in the 28th week of pregnancy. They are given a second dose if their baby is Rhesus positive. Why don’t they need the second dose if the baby is Rhesus negative? (10 points). May need 5-6 sentences for this one.
A second dose of anti -Rh antibody is given only if baby born to Rh negative mother is Rh positive. When foetal antibody cross placenta and mixes with mother's blood , mother's immune system recognise foetal antibody as foreign body and causes destruction of foetal antibodies causing erythroblastosis fetalis . But if baby is Rh negative there is no countering of foetus antibodies by mother's immunoglobin that is both are Rh negative . So there is no need of antibody against anti Rh. So second dose of ig is not given.
The Rh antibody is actually given to counteract the antibody which is generated by mother against Rh positive cells . If the baby is negative there is no necessity of a second dosage or there is no production of antibodies in mother's body that opposes foetal antibodies , so the treatment is not required.
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