Value of Toxoplasma gondii detection in one hundred thirty-three placentas for the diagnosis of congenital toxoplasmosis.

The placenta examination by polymerase chain reaction and mouse inoculation increased the sensitivity of the diagnosis of congenital toxoplasmosis at birth from 60% (use of serologic techniques on the newborn's blood only) to 75% (both serologic techniques and placental analysis). The specificity of Toxoplasma gondii detection in the placenta was 94.7%.