One hundred and ninety women who contracted toxoplasmosis after the se
venth week of pregnancy underwent antenatal diagnosis, including ultra
sound examination and biological tests. Tests included Toxoplasma isol
ation in fetal blood and amniotic fluid by mouse inoculation, specific
IgM and IgA in fetal blood, and non-specific tests. Twenty fetuses ha
d positive specific as well as non-specific tests for Toxoplasma infec
tion. At birth, four of these presented with clinical congenital toxop
lasmosis and 12 with subclinical forms. Antenatal diagnosis enabled th
e detection of 83 per cent of the infected fetuses. Under specific con
ditions, cordocentesis permits early diagnosis and considerably reduce
s the number of terminations of pregnancy.