The first expert offered by plaintiffs to show the antidepressant Zoloft caused birth defects in babies born to mothers who took it is still unacceptable, the federal judge handling the case has ruled.

U.S. District Judge Cynthia Rufe of the Eastern District of Pennsylvania stuck by her June decision to toss Dr. Anick Bérard from the case in an opinion she issued to answer the plaintiffs' steering committee's motion for reconsideration in the multidistrict litigation case that covers more than 600 plaintiffs.

In an unusual move earlier this month, Rufe allowed the plaintiffs to offer a second causation expert to the court over the forceful objection of Pfizer, which makes the drug.