Question

multiple choice question
following the first pregnancy with an rh+ fetus, the immune system of an an rh- woman produces anti-d antibodies. during her next pregnancy the baby is at
disease of the newborn (hdn), but only if which of the following is true?

the babys blood is rh+.

the mothers blood type has changed to rh+.

the babys blood is rh-.

the fathers blood is rh-.

Explanation:

HDN (Hemolytic Disease of the Newborn) related to Rh factor occurs when an Rh - woman has anti - D antibodies (from a previous Rh+ fetus exposure) and the next fetus is Rh+. The mother's blood type doesn't change. If the baby is Rh -, there's no Rh factor mismatch. The father's blood type alone isn't the direct trigger for HDN in the baby; it's the baby's Rh status relative to the mother's antibodies. So the baby's blood being Rh+ is necessary for HDN to occur as the anti - D antibodies will attack Rh+ blood cells.

Answer:

A. The baby's blood is Rh+