Final answer:
Rubella immunization during pregnancy can lead to Congenital Rubella Syndrome, which may cause developmental defects, birth defects, stillbirth, or miscarriage. It's crucial for the client to consult with healthcare providers for risks evaluation.
Step-by-step explanation:
The administration of rubella immunization to a client who was unaware she was pregnant poses a risk to the fetus. The rubella virus is teratogenic, which means it can cause developmental defects if it crosses the placenta and infects the fetus, leading to a condition known as Congenital Rubella Syndrome (CRS).
CRS is associated with a high incidence of birth defects, including heart defects, microcephaly, hearing and vision problems, and developmental delays. Similarly, infection by the rubella virus during pregnancy can lead to stillbirth or miscarriage if the mother gets infected with rubella during the first trimester.
If a client has received a rubella vaccination during pregnancy, it is important to consult with healthcare providers for close monitoring and evaluation of potential risks to the unborn child.