Primodos report 'questionable' and 'irresponsible,' says expert

A leading expert in embryo development has challenged the findings of a Government commissioned report into the pregnancy test drug Primodos.

Neil Vargesson, a senior lecturer at the Institute of Medical Sciences in Aberdeen, describes some of the conclusions as "questionable" and "irresponsible."

Campaigners have long argued that the hormone-based drug used by women in the 1960s and 1970s caused some babies to be born with severe birth defects.

But a report published last week by the Commission on Human Medicines (CHM) concluded that "available scientific evidence… does not support a causal association between the use of HPTs (hormone pregnancy tests), such as Primodos, during pregnancy and adverse outcomes" such as malformations.

In a letter to Sky News, Dr Vargesson says: "I really don't think it is possible, with the current published evidence, to formally and directly conclude Primodos did not cause harm or imply that it was completely safe.

"Indeed, with the scientific data we currently have, can anyone really put their hand on their heart and confidently say that taking Primodos did not and would not cause damage to the embryo?"

His comments come as MPs from a cross-party group prepare to quiz members of the CHM about their conclusions.

Last week, there was an urgent question in the Commons after Sky News revealed that the draft report had differed from the final publication in its conclusion.

Campaigners also argued that the evidence had not been properly assessed and the expert group had veered from its original terms of reference. Some MPs described the report as "a whitewash."

Dr Vargesson is the only expert to conduct recent studies on Primodos, finding that it can cause malformations to fish embryos.

He challenges the CHM report's assertion that the findings should "provide reassurance" to women who today use some of the components of Primodos in high doses for other conditions and may fall pregnant inadvertently.

He says: "I find this a little questionable, if not somewhat irresponsible. The doses of noretheristerone acetate (a component of Primodos) used in these treatments are higher than the dose used in Primodos (10mg).

"Moreover, some of the scientific studies, that the working group considered flawed, actually showed that higher doses of these components of Primodos were harmful if not lethal to the embryo."

Dr Vargesson agrees with the CHM that many of the scientific studies available to assess were outdated and may have been flawed for a variety of reasons.

However, he suggests that this should have prompted the committee to suggest further studies be conducted using modern techniques.

Dr Vargesson notes: "Some of these old studies do seem to indicate that Primodos exposure at least has the potential to cause damage or harm to the embryo.

"So I do remain a little surprised that the group concluded there is no causal link between Primodos and the causation of birth defects."

A spokesperson for Bayer AG, which acquired Primodos manufacturer Schering in 2006, said: "Bayer notes that a review by an independent expert working group on hormone pregnancy tests of the Commission on Human Medicines has found, consistent with Bayer's view, based on all available data, that the scientific evidence does not support a causal association between the use of hormonal pregnancy tests, such as Primodos, and birth defects or miscarriage."