Adverse fetal outcome in the absence of timely prenatal diagnosis of congenital toxoplasmosis

Summary OBJECTIVE: Toxoplasma gondii infection acquired during pregnancy may lead to transplacental transmission and jeopardize the course and outcome of pregnancy, leading to life-threatening disease in the fetus and the newborn. CASE REPORT: Here we present a case of medically terminated pregnancy due to clinically manifested congenital toxoplasmosis (CT) which was proven serologically, as well as by bioassay. Ultrasonographically visualized severe fetal ventriculomegaly in a seven-month pregnant 33-year-old woman with a history of three months of lymphadenopathy was an indication for extensive testing for toxoplasmosis. Based on the serological results obtained (high specific IgG antibodies of borderline but close-to-low avidity, along with the finding of specific IgM antibodies), maternal infection was dated to the second trimester. Cord blood serology revealed IgG levels lower than those of the mother's, but both specific IgM and IgA antibodies were detected, indicating fetal infection. Although Toxoplasma DNA was not detected in the cord blood sample by real-time PCR, fetal infection was definitely confirmed after six weeks by cord blood bioassay results. While no morphologically recognizable Toxoplasma cysts were found, murine serology was positive. Since fetal morphological abnormalities, which could not be reversed by subsequent treatment, were already advanced at the time of serological testing, the patient opted for termination of pregnancy. CONCLUSION: This case demonstrates the potentially severe outcome of CT as a result of central nervous system affection, emphasizing the need for prompt and precise prenatal diagnosis in case of maternal seroconversion, so that proper treatment may be introduced in a timely manner.