Effectiveness of prenatal treatment for congenital toxoplasmosis: a meta-analysis of individual patients' data.
BACKGROUND
Despite three decades of prenatal screening for congenital toxoplasmosis in some European countries, uncertainty remains about the effectiveness of prenatal treatment.


METHODS
We did a systematic review of cohort studies based on universal screening for congenital toxoplasmosis. We did a meta-analysis using individual patients' data to assess the effect of timing and type of prenatal treatment on mother-to-child transmission of infection and clinical manifestations before age 1 year. Analyses were adjusted for gestational age at maternal seroconversion and other covariates.


RESULTS
We included 26 cohorts in the review. In 1438 treated mothers identified by prenatal screening, we found weak evidence that treatment started within 3 weeks of seroconversion reduced mother-to-child transmission compared with treatment started after 8 or more weeks (adjusted odds ratio [OR] 0.48, 95% CI 0.28-0.80; p=0.05). In 550 infected liveborn infants identified by prenatal or neonatal screening, we found no evidence that prenatal treatment significantly reduced the risk of clinical manifestations (adjusted OR for treated vs not treated 1.11, 95% CI 0.61-2.02). Increasing gestational age at seroconversion was strongly associated with increased risk of mother-to-child transmission (OR 1.15, 95% CI 1.12-1.17) and decreased risk of intracranial lesions (0.91, 0.87-0.95), but not with eye lesions (0.97, 0.93-1.00).


CONCLUSIONS
We found weak evidence for an association between early treatment and reduced risk of congenital toxoplasmosis. Further evidence from observational studies is unlikely to change these results and would not distinguish whether the association is due to treatment or to biases caused by confounding. Only a large randomised controlled clinical trial would provide clinicians and patients with valid evidence of the potential benefit of prenatal treatment.
INSERM, Bordeaux, France.
Thiébaut
Rodolphe
R
Leproust
Sandy
S
Chêne
Geneviève
G
Gilbert
Ruth
R
D003049:Coccidiostats / Q000627:therapeutic use*; D005060:Europe; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D016015:Logistic Models; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology; D011296:Prenatal Diagnosis / Q000191:economics / Q000379:methods*; D015572:Spiramycin / Q000627:therapeutic use*; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis / Q000188:drug therapy / Q000635:transmission; D016896:Treatment Outcome
D003049:Coccidiostats; D015572:Spiramycin