January 9, 2015 — Law360 reports that plaintiffs will be allowed to introduce a new expert witness to help support their claims that Pfizer’s blockbuster antidepressant Zoloft can cause birth defects when it is used during pregnancy.

U.S. District Judge Cynthia Rufe said that plaintiffs can introduce Nicholas Jewell, a professor at the University of California, Berkley’s School of Public Health and its statistics department, as their new causation expert.

Last year, Judge Rufe banned testimony from the plaintiff’s initial key expert, Dr. Anick Bérard, who was supposed to testify about evidence linking Zoloft to a wide variety of birth defects.

Judge Rufe found that Dr. Bérard “failed to base her opinion upon scientifically valid methodology and reasoning.”

In a separate opinion, Judge Rufe also barred key testimony from three other witnesses. She barred the experts from testifying about birth defects in humans, but said she would allow them to answer questions limited to the biological mechanisms in which abnormal serotonin levels could cause birth defects.

The new expert, Nicholas Jewell, will testify on research linking the use of Zoloft during pregnancy to heart defects in babies. According to Judge Rufe:

“It appears that Dr. Jewell’s proposed expert testimony encompasses a significantly more limited range of birth defects than did Dr. Berard’s.”

Pfizer is facing about 60 lawsuits involving cardiovascular defects caused by Zoloft, according to The Legal Intelligencer. As of December 2014, about 528 Zoloft lawsuits remain pending in federal court.