Prevention of Congenital Toxoplasmosis With Pyrimethamine + Sulfadiazine Versus Spiramycine During Pregnancy

Multicenter, Randomized Clinical Trial to Compare the Efficacy and Tolerance of Prenatal Therapy With Pyrimethamine + Sulfadiazine vs Spiramycine to Reduce Vertical Transmission of Toxoplasma Gondii Following Primary Infection in Pregnancy

Background : When a mother contracts toxoplasmosis during pregnancy, the parasite may be transmitted from to her unborn child. This results in congenital toxoplasmosis, which may cause damage to the eyes and nervous system of the child. To date, no method has been proved effective to prevent this transmission. In France, spiramycin is usually prescribed to women who have toxoplasma seroconversion in pregnancy, however its efficacy has not been determined. The standard treatment for toxoplasmosis is the combination of the antiparasitic drugs pyrimethamine and sulfadiazine, but this strategy has not been evaluated for the prevention of mother-to-child transmission.

Purpose : Randomized phase 3 trial to determine whether pyrimethamine + sulfadiazine is more effective than spiramycin to prevent congenital toxoplasmosis.

The protocol is a comparison of 2 strategies to prevent mother-to-child transmission of T. gondii following maternal seroconversion.

Screening for toxoplasmosis is mandatory in France. Patients with confirmed seroconversion will be eligible for the trial, after 14 weeks gestational age.

Participants will be randomly allocated to one of the treatment groups, and will receive open-label pyrimethamine + sulfadiazine or spiramycin.

The protocol will not change the usual procedures for prenatal diagnosis, nor will it change the management of infected fetuses and neonates.

Inclusion Criteria:

• > 18 years old
• Toxoplasmosis infection acquired during the pregnancy documented by at least one negative serology in the first trimester and seroconversion with presence of specific IgG antibodies
• Gestational age > 14 weeks from last menstrual period
• Signature of informed consent

Exclusion Criteria:

• Lack of a documented negative serology during the pregnancy
• Antiparasitic therapy with spiramycin, pyrimethamine or sulfa drugs for more than 10 days after seroconversion and before randomization,
• Known allergy to any of the study drugs, serious allergic conditions or G6PD deficiency,
• Known hepatic or renal insufficiency,
• Other ongoing severe conditions in mother or fetus
• Lack of public health insurance