[Severe fetopathy--toxoplasma despite serologic screening. A case report].

Toxoplasmosis is a special prenatal infection because it is susceptible to medication. Serologic screening and early diagnosis of a new infection is a prerequisite for successful treatment, which protects the fetus from infection. A case of a twenty-two year old gravida-II shows, that infection is possible despite negative initial screening. A new infection was diagnosed because of seroconversion at a routine screening at the end of the second trimester. An ultrasound scan showed severe hydrocephalus, hepatomegaly, and ascites. Labor was induced in the 33rd gestational week. Conatal toxoplasmosis was confirmed by histologic and microbiologic studies of the placenta and membranes. We discuss the difficulties resulting from negative primary serology.