Infection during pregnancy can lead to severe fetal defects; which virus is known for this teratogenic risk?

• A. Rubella
• B. Influenza
• C. Hepatitis B
• D. Polio

Answer: (A)

Some viral infections during pregnancy can cause birth defects, with rubella being the classic example of a teratogenic virus. If a fetus is exposed to rubella, especially in the first trimester, congenital rubella syndrome can develop. This can lead to serious outcomes such as cataracts, sensorineural deafness, and heart defects like patent ductus arteriosus, as well as potential microcephaly and developmental delays. Because of this risk, vaccination with the MMR vaccine is recommended before pregnancy, and nonimmune individuals should avoid rubella exposure and receive vaccination after delivery rather than during pregnancy.

Influenza, while important to prevent because it can harm both mother and fetus, is not known for causing the specific birth defects associated with rubella. Hepatitis B can be transmitted to the baby around birth, leading to neonatal infection, but it does not create the congenital malformations seen with rubella. Polio likewise does not cause characteristic fetal birth defects.