Around 20,000 women and girls taking sodium valproate are to receive advice about the risks of taking the drug in pregnancy, the NHS has announced.

The anti-epilepsy drug sodium valproate has been linked to physical malformations, autism and developmental delay among some children when it is taken by their mothers during pregnancy.

Meanwhile a data registry has been established to better track sodium valproate prescriptions to women with epilepsy.

It comes almost a year after a scathing review into three NHS scandals – including the anti-epileptic drug sodium valproate – concluded that thousands had come to “avoidable harm” and their concerns were “dismissed and overlooked”.

The Independent Medicines and Medical Devices Safety Review, published in July 2020, concluded that women were still falling pregnant while taking the drug “without any knowledge of the risks”.

The report said it had taken “too long” for the healthcare system to respond to concerns about the widely used medication.

One of the recommendations of the review called for a registry of all women on anti-epileptic drugs who become pregnant.

Meanwhile, the authors also called for the NHS to write to all women “of childbearing potential” who are taking the drug asking them to see their GP for a medicine review.

Now the NHS has said that 20,000 women and girls aged 12 to 55 who are recorded as having an active prescription for the drug are to receive a letter outlining a number of actions to take if they are pregnant, trying for a baby or have not had a recent medication review.

The letter, from the NHS director of patient safety Dr Aidan Fowler, will urge those with an active prescription to continue their treatment course until their doctor tells them otherwise.

The NHS in England said that a new data registry has also been established, managed by NHS Digital, to better track prescriptions to women.

Dr Fowler said: “Valproate is the best treatment available for a small group of people with very complex illnesses, so it’s vital those who have an active prescription for it continue taking it until they are told otherwise by their GP or consultant.

“It’s vital too however that everyone understands the risk that doing so poses to your unborn child if you are pregnant, and this letter is a reminder of information that every woman and girl of childbearing age should receive from their doctors when the drug is first prescribed.”

Louise Cousins, director of external affairs at Epilepsy Action, said: “We welcome any further measures to ensure that women and girls are made aware of the risks of taking valproate and other medicines while pregnant.

“Despite recent efforts, we know there are still women who are unaware of these risks.

“This NHS letter, while rather late in the day, should help women taking sodium valproate feel more informed and empowered to prompt conversations with their doctor about their medication.

“It is only then that they can make truly informed decisions.

“However, GPs and health professionals need the time and resources to make sure these conversations are actually happening, and happening early.

“They need to make sure women are fully informed about the risks of sodium valproate before they start taking it. More also needs to be done to identify potential risks of taking other epilepsy medicines in pregnancy.

“Epilepsy Action is therefore continuing to call for all women with epilepsy to receive pre-conception counselling and family planning advice. Women should not stop taking their epilepsy medicine before talking to their doctor.”

Research suggests that 10% of unborn children exposed to the medication are likely to suffer physical birth defects such as spina bifida and cleft palate, heart problems and limb defects, and 40% will have a developmental delay or autism.

The drug was approved for use in 1974.

The NHS said in a press release that the medicine has “always carried warnings for doctors about the possible risks if it is taken while pregnant”.

But the review into valproate concluded that: “Women are still becoming pregnant whilst on valproate without any knowledge of the risks.”

The review set out how the drug was a known “teratogenic” – a medicine harmful to a developing foetus – in animals at the time of licensing.

“As data emerged on the risks of the use of sodium valproate over the decades, it took too long for action to be taken by the healthcare system to ensure that risks were minimised,” the report states.

“Women should have been warned, even if there were no alternatives, so that they could be better prepared.”

The authors said that it took four decades for the “healthcare system to put into place measures to ensure that women were fully informed of the risk prior to becoming pregnant”.

Commenting on the letter and registry, Susan Cole, from the campaign group Valproate Victims, said: “Campaigners have been working for over 20 years to ensure that the risks of valproate in pregnancy are recognised.

“Despite warnings in the materials that consultants should have read and should have guided them, women have not been given enough information with which to make informed decisions.

“We welcome that the NHS are reinforcing rules about valproate and it’s important to us that this new approach is used as a blueprint for other medicines and even environmental teratogens that may affect women in pregnancy.”