Effect of timing and type of treatment on the risk of mother to child transmission of Toxoplasma gondii.
OBJECTIVE
To determine the effects on mother to child transmission of the timing and type of prenatal treatment, taking into account gestational age at maternal seroconversion.


METHODS
Prospective cohort study.


METHODS
European centres offering prenatal screening for toxoplasmosis.


METHODS
Children born to a cohort of pregnant women with toxoplasma infection.


METHODS
We determined the effects on mother to child transmission of the interval between seroconversion and start of treatment (treatment delay), and the type of treatment, taking into account gestational age at maternal seroconversion.


METHODS
Congenital infection status confirmed by toxoplasma IgG results at one year postnatal age.


RESULTS
Of 1208 women analysed, 72% were first prescribed spiramycin, 19% pyrimethamine-sulphonamide and 9% (mostly infected during the last trimester) were untreated. The odds ratios for mother to child transmission for all women treated after a delay of four to seven weeks was 0.77 (95% CI 0.34-1.69), and after eight weeks or more was 1.33 (0.56-2.89) compared with less than four weeks. The odds ratio per week of treatment delay was 1.01 (0.93-1.08). There was no evidence that transmission risk differed in women first treated with pyrimethamine-sulphonamide versus spiramycin: odds ratio 1.10 (0.63-1.91) or in untreated versus treated women: odds ratio 0.57 (0.27-1.17).


CONCLUSIONS
We were unable to demonstrate a beneficial effect of the timing or type of prenatal treatment on the risk of mother to child transmission but we could not exclude a clinically important effect. Randomised controlled trials are required to determine the effect of prenatal treatment on mother to child transmission.
Gilbert
R
R
Centre for Paediatric Epidemiology and Biostatistics, Institute of Child Health, London, UK.
Gras
L
L
D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D000981:Antiprotozoal Agents / Q000008:administration & dosage*; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005260:Female; D005865:Gestational Age; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000188:drug therapy*; D011296:Prenatal Diagnosis / Q000379:methods / Q000451:nursing; D011446:Prospective Studies; D011739:Pyrimethamine / Q000008:administration & dosage; D012307:Risk Factors; D015572:Spiramycin / Q000008:administration & dosage; D013449:Sulfonamides / Q000008:administration & dosage; D013997:Time Factors; D014123:Toxoplasmosis / Q000188:drug therapy* / Q000635:transmission
D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D013449:Sulfonamides; D015572:Spiramycin; D011739:Pyrimethamine