Which disease or for what purpose torch test is conducted?

A placenta infection: Torch is an infection of the placenta that can cause fetal death or fetal growth retardation. It stands for toxoplasmosis, rubella, cytomegalovirus and herpes simplex type 2. Toxoplasmosis is a parasite infection, all the others are infections caused by viruses. Evidence of a torch infection may be looked for in a mother who has a miscarriage or delivers a baby who is small for gestational age.