The prime minister has promised to review new evidence suggesting pregnancy test Primodos caused birth deformities to babies of mothers who used it.

Suspicions about the drug have led to a decades-long campaign by parents and children who believed it caused a range of problems from heart damage to shortened limbs.

The prescription handed out by GPs was made up of two pills which tested for pregnancy by inducing a period in women who had not conceived.

It was taken off the market in 1978 amid concerns about the effect on the unborn child of those who were pregnant, but the link has never been formally recognised by regulators or the manufacturer.

An investigation by Sky News in 2017 found that evidence of an association had been destroyed by a UK regulator in the 1970s.


Image: Primodos was given to pregnant women in the 1960s and 70s

Recently, a team led by professor of evidence based medicine at Oxford University, Carl Heneghan, conducted a review of all human studies on the drug and discovered that the pooled data shows "a clear association" with several forms of malformation.

Primodos' links to birth defects revealed

Speaking in the House of Commons Theresa May said "ministers are aware of the new study that has come out" and it will be "looked at very carefully."

Labour MP Yasmin Qureshi raised the issue during prime minister's questions. She said: "In the 1960's and 70's 1.2 million Primodos pills were prescribed to women including three of my constituents."

"One dosage was equivalent to 40 oral contraceptives. Thousands of babies were born with deformities.

"A recent MHRA review was widely criticised for being a whitewash.

"Now Professor Carl Heneghan at Oxford University has published a review of the scientific data that clearly shows Primodos did cause deformities.

"Will the prime minister ensure that any review that's carried out is independent of the MHRA (Medicines and Healthcare products Regulatory Agency) because we have no faith in them?"

'Just apologise... What they want is an apology'

The prime minister responded: "Obviously it is an important issue.

"It has been raised by a number of members from across the house and our priorities is always on the safety of patients and ministers are aware of the new study that has come out.

"We have a commitment to review any new evidence in this area and we do that by consulting independent scientific experts.

"Baroness Cumberlege is leading the independent medicines and medical devices safety review.

"That's expected to examine what happened the case of Primodos and determine what further action is needed. But can I reassure the honourable lady that we will listen very carefully to any recommendations that come out of the review. And that study will be looked at very carefully."

Image: Theresa May has promised to look at new evidence

An MHRA spokesperson responded to the Oxford University study, saying: "This publication, which is currently awaiting peer review, does not contain new data.

"It is a different approach to the analysis of existing historic observational data which was reviewed by the Commission on Human Medicines' Expert Working Group on Hormone Pregnancy Tests.

The manufacturer who took over Primodos-makers Schering has said: "Bayer is aware of the ongoing Independent Medicines and Medical Devices Safety Review.

"This follows a review by an Independent Expert Working Group on Hormone Pregnancy Tests of the Commission on Human Medicines that has already found, consistent with Bayer's view and based on all available data, that the scientific evidence does not support a causal association between the use of hormone pregnancy tests, such as Primodos, and birth defects or miscarriage."