[Antenatal diagnosis of toxoplasmosis. 176 case reports]

To determine the value of antenatal diagnosis of congenital toxoplasmosis by ultrasound guided aspiration of cord blood for testing.

This is a prospective study of 176 cases. As well as obtaining fetal blood and amniotic fluid the searched for specific IgM and A as well as culturing for the parasites on human fibroblasts and inoculation of mice, as well as researching them for non-specific signs of fetal infection. 149 children were able to be followed up one year after birth.

15% of the children (22/149) were infected with toxoplasmosis. 11 out of these were diagnosed positive antenatally. For the 11 others the diagnosis of fetal infection could only be made after birth, but the non-specific signs made it possible to expect early that they had been contaminated. 59% (13/22) had latent toxoplasmosis which only showed up after a mean interval of 34 months after birth. 41% (9/22) had clinical and/or paraclinical signs of toxoplasmosis (mainly unilateral non-macular chorioretinitis and intracranial calcifications) but they are well after a follow-up period averaging 30 months.

Ultrasound alone, when it shows up fetal abnormalities, can make the diagnosis of the severity of the condition. The role of taking fetal specimens is to make clear those infants that are infected because of specific signs, and to find those fetuses which are at high risk because of non-specific signs in order to improve the management of the cases. This development has made it possible to avoid carrying out a large number of unnecessary terminations of pregnancy and has resulted in the birth of affected infants that had no functional sequelae from the infection.