[Maternal toxoplasmosis before conception and chorioretinitis in twin sisters].

A maternal toxoplasmosis before conception is exceptionally transmitted to the fetus. We report an observation of twin sisters who presented congenital toxoplasmosis with chorioretinitis detected at nine months of age. The anamnesis revealed that the mother had had toxoplasmosis one month before conception. In the event of preconceptual infections, we propose fetal ultrasonography, histological examination of the placenta at delivery, as well as a pediatric follow-up of the infants (serological samples every month, cranial ultrasonography, fundus oculi).