Objective: Evaluate the frequency and discuss the mechanisms and the prognostic value of sonographic anomalies observed during the surveillance of seroconversion for toxoplasmosis during pregnancy.
Methods: Cases of seroconversion during pregnancy were collected from 6 teams working with similar protocols. There were 2,168 seroconversions. We focused on ultrasound anomalies reported.
Results: Ultrasound anomalies were reported in 48 cases including the 168 fetuses with proven contamination (fetal blood or amniotic fluid sample), i.e. 2.2% (48 cases out of 2,168) of the seroconversions and 28% (48 cases out of 168) of the contaminated fetuses. There were multiple lesions in 44% of the cases. Brain calcifications had been found in utero in 44% of the newborns with such anomalies. No case of microcephalia was reported. Isolated hepatomegalia (4 cases) was not an indication for medical abortion. Isolated ascitis can regress after antiparasite treatment (2 cases). Medical abortions were performed in 51% of the cases (34 cases out of 66) on the basis of ultrasound findings.
Conclusion: Ultrasound examination is reliable but can only detect late, constituted and often irreversible lesions. Nevertheless, this examination can help in deciding on medical abortion.