The aim of this study was to determine the incidence of congenital toxoplasmosis (CT) and to assess the performances
of prenatal and neonatal diagnoses. From 1994-2005, in Toulouse University Hospital, France, amniocentesis
was performed on 352 pregnant women who were infected during pregnancy. All women were treated with
spiramycin and pyrimethamine-sulfadoxine when prenatal diagnosis was positive. Among the 275 foetuses with
follow-up, 66 (24%) were infected. The transmission rates of Toxoplasma gondii
were 7%, 24% and 59% in the first,
second and third trimesters, respectively. The sensitivity and specificity of PCR on amniotic fluid (AF) were 91% and
99.5%, respectively. One case was diagnosed by mouse inoculation with AF and six cases were diagnosed by neonatal
or postnatal screening. The sensitivity and specificity of PCR on placentas were 52% and 99%, respectively.
The sensitivity of tests for the detection of specific IgA and IgM in cord blood was 53% and 64%, respectively, and
specificity values were 91% and 92%. In conclusion, PCR performed on AF had the highest levels of sensitivity and
specificity for the diagnosis of CT. This permits an early diagnosis of most cases and should be recommended.