[Toxoplasmosis in pregnancy: recent acquisitions and new prospects]

Congenital toxoplasmosis may develop after maternal primary infection during pregnancy. The infection is usually asymptomatic in pregnant women but poses a risk of severe effects on the fetus. In Italy the incidence is about 6 per thousand. The infection is transmitted to the fetus in approximately 50 percent of such cases. The risk of transmission rises with growing gestational age at the time of primary infection; on the contrary, the seriousness of the effect on the fetuses becomes less active with more advanced pregnancies. Infants with congenital toxoplasmosis are mostly asymptomatic at birth but long-term studies have indicated that up to 85% of them will develop serious sequelae as severe impairment of vision, mental retardation and deafness during the months or the years after the birth. Preventing congenital toxoplasmosis is fundamental. All seronegative women should be encouraged to observe good dietary and general health regulations until delivery. Today the diagnosis in the mother is more reliable because of the improvements in serological techniques. Moreover, it is possible to identify infected fetuses by prenatal procedures such as ultrasonography, amniocentesis and cordocentesis, of which the last two consent to detect the parasite and/or specific antibodies. Recently a polymerase chain reaction (PCR) assay has been developed for the detection of Toxoplasma in the amniotic fluid. Adequate serological screening of pregnant and prenatal diagnosis can be helpful in reducing the incidence of congenital toxoplasmosis; furthermore abortion should be reserved only to cases with severe toxoplasmosis revealed by ultrasonography. Early recognition of pregnant infection and a specific treatment could reduce the parasitic colonization in the placenta by more than 60% and prevent infection in the fetus. If the fetal infection has already occurred, maternal treatment may modify the fetal disease. Spiramycin as immediate treatment of maternal primary infection is essential in preventing Toxoplasma transmission to the fetus. If the fetus results non-infected, spiramycin should be prolonged until delivery. If the fetus is infected, pyrimethamine-sulphadiazine combination should be given in repeated courses alternated with courses of spiramycin. However, there is an urgent need for more active and safer compounds; it would be useful to evaluate in the pregnant woman other potential therapeutic agents as atovaquone and azithromycin.