To establish causation in a pharmaceutical products liability action, scientific expert testimony must be generally accepted by the relevant medical community, a Pennsylvania court held.

While pregnant with her son Jeffrey, Joan Blum was prescribed Bendectin to combat morning sickness. Jeffrey was born with clubfeet and the Blums took Merrell Dow, the pharmaceutical manufacturer, to court. To prove that Bendectin caused Jeffrey's clubfeet, the Blums presented the expert testimony of three doctors, all of whom testified as to the drug's potential to cause birth defects in embryos. Each expert witness gave shaky testimony-none of their scientific findings regarding Bendectin and birth defects had been published and one doctor went so far as to say he was "unsure" about drug testing results. The trial court, however, admitted the testimony, claiming confidence in the power of cross-examination to expose unreliable expert testimony and criticizing the judicial shackles of the Frye test, which attempts to measure the reliability of scientific evidence before it is admitted. The end result was a $24,000,000 reward in favor of the Blums. Merrell Dow appealed.

The Superior Court of Pennsylvania reversed and remanded the decision of the lower court. Testimony by an expert, the court held, does not become scientific knowledge just because it is uttered by a scientist. While the court gave deference to the trial court's passionate opinion, it held that the Frye test exists for a very certain purpose—to ensure that unreliable scientific evidence never reaches the ears of jurors. The Blums did not meet their burden of proving that their experts' methodologies were generally accepted in the medical community. The court remanded with instructions to enter judgment notwithstanding the verdict in favor of the pharmaceutical company.