By Ralph D. Levinson, MD
This retrospective study found that the recurrence rate of ocular toxoplasmosis does not appear to be higher during pregnancy, in contrast to traditional beliefs.
Episodes of ocular toxoplasmosis occur most commonly during the childbearing years. This can be a difficult therapeutic challenge as most episodes are treated with systemic medications when treatment is indicated, although local therapy, such as intravitreal clindamycin, can be considered.
While the authors are appropriately circumspect in their conclusions given the retrospective nature of the study, it is reassuring that despite “traditional” beliefs there is evidence that the rate of recurrence does not appear increase during pregnancy.
They sent questionnaires to all women who experienced an episode of active toxoplasmosis at a childbearing age (16 to 42 years) seen at University Medical Center in Utrecht, the Netherlands, between 1995 and 2005.
Eighty-six women with one or more episodes of active toxoplasmic retinochoroiditis during childbearing years had been seen there during those years. Of these women, 50 responded to the questionnaire and were included in the study.
There were 128 episodes of toxoplasmosis during the study period, six of which were during pregnancy. The mean age of the first episode was 25.4 years, although in seven cases the first episode occurred before age 16. The authors found that these episodes were less frequent during pregnancy.
They note that these results have scientific and public health implications. Previous reports of the higher risk of recurrent toxoplasmosic retinochoroiditis during pregnancy have been taken as presumptive evidence of a role for hormonal influences in the pathogenesis of ocular toxoplasmosis, which may not be true.
They conclude that further study of this issue will be facilitated by inclusion of information about pregnancy history among demographic and medical data collected in prospective, longitudinal clinical studies. Finally, these findings do not diminish the importance of ocular toxoplasmosis during pregnancy as an important management issue.