Inadequate numbers

We noted with interest the article “Paternal use of ribavirin–interferon alpha 2B combination therapy before conception” by Taguchi and Ito (Can Family Physician 2005;51:1623–5). In their conclusion the authors state, “Although ribavirin is a potential teratogen, there seems to be no immediate reason for terminating pregnancy when a father has been exposed to it.” A note of caution is in order, however, because their conclusion is based on only 12 live births and 7 spontaneous or induced abortions where the outcome was not known. In 2003, the United States Food and Drug Administration required all ribavirin manufacturers to form the Ribavirin Pregnancy Registry, a prospective, observational, exposure-registration and follow-up program. Since January 2004, more than 70 pregnancy outcomes related to paternal exposure to ribavirin have been reported to the Registry, a number we, as members of the Scientific Advisory Board of the Registry, consider inadequate for drawing conclusions regarding the safety of ribavirin exposure during human pregnancy. Enrolment in this United States–based registry is ongoing. Health care providers and patients can visit the website (www.ribavirinpreg-nancyregistry.com)for additional information.

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