Primary Toxoplasmosis Acquired During Early Pregnancy: Is it Currently Overestimated?

One of the more severe infectious complications for fetuses is primary toxoplasmosis acquired during pregnancy, especially when this occurs during the first trimester, as this infection can have devastating neurological consequences. The generally asymptomatic nature of this infection in healthy pregnant women requires serological screening or testing. This study aimed to evaluate the risk of transplacental infection in pregnant women with suspected or confirmed toxoplasmosis in the first 16 weeks of gestation detected at the Tuscany Reference Center for Infectious Diseases in Pregnancy in Florence, Italy during the last 20 years. This study was a retrospective study of cases of suspected or confirmed acute toxoplasmosis acquired within 16 gestational weeks in pregnant women undergoing amniocentesis and evaluated through the Tuscany Reference Center for Infectious Diseases in Pregnancy from November 1999 to December 2019. The study included 237 pregnant women with suspected or confirmed toxoplasmosis. Excluding 24 newborns without outcome data, the prevalence of congenital infection was 0.47% overall (1/213; 95% confidence interval [CI], 0.08%–2.61%), including 0% (0/178; 95% CI, 0%–2.11%) in suspected and 2.8% (1/35; 95% CI, 0.51%–14.53%) in confirmed disease. The main limitation of the study was its retrospective design, whereas its main strength was the confirmation of findings from 2 previously performed separate studies using patients with suspected acute infection and confirmed acute infection. Findings of the study indicated that toxoplasmosis acquired in early pregnancy yields a low risk of fetal infection. The authors conclude that amniocentesis should be considered on a case by case in order to prevent unnecessary transmission of infection.