The risk of maternal-foetal transmission varies depending on the age of pregnancy in which the primoinfection occurs, being inversely proportional. Thus, although the risk of transmission to the fetus is lower in the first trimester, the risk of fetal suffering is maximum.

Congenital toxoplasmosis in function of the infection time of the conception product:

• Fetal death in uterus and spontaneous abortion in the first trimester of pregnancy
• Serious malformations in quarters 2 and 3
• Subclinical infections at the end of pregnancy; but untreated these infections can lead in time to corioretinitis, decreased hearing, delays in development.
• The more advanced the pregnancy increases the risk of “fetal touch” but decreases the severity of potential injuries;
• The risk of transplacental transmission is approximately 15% in the first quarter, approximately 30% in the second quarter and approximately 60% in the third quarter (not always an infected placenta transmits infection to the fetus).

Riscul transmiterii toxoplasmozei congenitale și dezvoltarea semnelor clinice la copiii cu vârsta sub 3 ani, în relație cu vârsta sarcinii la care a avut loc seroconversia

* The study was conducted on 603 women infected with TG (Toxoplasma Gondii) during pregnancy. 84% of these received treatment for toxoplasmosis.

* * The study was conducted on 1721 women infected with TG during pregnancy. All pregnant women were treated.

* Montoya JG, Remington S. Management of Toxoplasma gondii infection during Pregnancy. ClinInfectDis 2008; 47:554-66.

* * Thiebaut R, Leproust S, Chene G, Gilbert R. Effectiveness of the Preneta treatment for congenital toxoplasmosis: A meta-analysis of individual patients data. The Lancet 369, 2007; 9556:115-122.

Maternal-foetal transmission occurs predominantly in women with primoinfection during pregnancy; Cases of congenital toxoplasmosis occurring in mothers with chronic infection and reactivated during pregnancy are extremely rare and require the existence of a immunosupression state (AIDS or tratement with Corticoids).

In 80% of cases primoinfection with TG in adults with normal immunity is asymptomatic, and in 20% of cases the clinical picture is multiforme, not specific: febrile condition, asthenia, myalgia, sometimes oral enanthem, pharyngitis or haematological mononucleosis syndrome ( Leukocytosis with lymphomonocytosis, with atypical lymphocytes).

Studies report that more than 50% of mothers who had children with congenital toxoplasmosis had no symptoms or could identify a risk factor.

Older studies from 2001 that included patients from France, Austria, Germany and Denmark placed the risk of transmission of toxoplasmosis to the foetus between 21-28%.

(Gilbert R, Dunn D, Wallon m, Hayden M, Prusa A, Lebech m, Kortbeek T, Peyron F, Pollak A, Petersen E. Ecological comparison of the risks of mother-to-child transmission and clinical manifestations of congenital toxoplasmosis according to prenatal treatment Protocol. Epidemiology and infection. 2001 APR 1; 127 (01): 113-20).

Studies from 2003 reported a 18.1% risk of intrauterine death in pregnant women who had Ig G positive for toxoplasmosis compared to 9.7% in pregnant people who were negative for Ig G anti T. Gondii and who had healthy children.

(Elnahas A, Gerais AS, Elbashir M. Toxoplasmosis in pregnant sudanense women. Saudi Medical Journal. 2003; 24 (8): 868-70.).

The risk of transmission is lower in more recent studies, thus in 2012, a retrospective study on 685 women identified a transmission rate of 4.8%, with clinical manifestations at 1.6%.

(Hotop A, Hlobil H, Groß U, et al. Efficacy of rapid treatment initiation following primary Toxoplasma gondii infection during pregnancy. Clinical Infectious Diseases. 2012 Jun 1; 54 (11): 1545-52.).

A study that analyzed the effectiveness of prenatal treatment in the case of Toxoplasmosis has highlighted that from 554 newborn infants from infected mothers, the infection was transmitted to 161 babies.

(Gilbert RE, Fat L, Wallon M. Effect of prenatal treatment on mother to child transmission of Toxoplasma gondii: retrospective cohort study of 554 mother-child pairs in Lyon, France. International Journal of Epidemiology. 2001 DEC 1; 30 (6): 1303-8).