The federal judge overseeing the Zoloft multidistrict litigation has postponed the Daubert hearing in the case after a medical expert discovered alleged errors in an article about the drug’s risk of causing congenital heart defects.

Defendant Pfizer’s medical expert, Dr. Stephen E. Kimmel, wrote in a report that one of the two independent studies that purportedly showed that Zoloft increases the risk of heart defects in newborns contained allegedly incorrect data. Kimmel wrote that he contacted the author to inform him of discrepancies in the article, which appeared in the New England Journal of Medicine.