The health service is seeking to recruit extra geneticists to test children for birth defects caused by an epilepsy drug taken by their mothers during pregnancy.

A surge in demand for genetic testing is expected once the Health Service Executive (HSE) starts writing to women in the coming weeks to warn them of the risk involved in taking sodium valproate while pregnant, according to sources.

The demand will put further pressure on the overburdened clinical genetics service at Our Lady's Hospital in Crumlin. More than 2,200 adults and children are waiting to see a geneticist there, 500 for 18 months or longer.

It is estimated around 400 children have suffered development or physical problems because of the drug. Only 43 have been formally diagnosed with foetal anticonvulsant syndrome, the condition associated with it, according to evidence to an Oireachtas committee. The committee reported last month that genetic testing was required to ensure correct diagnoses and that the State "has responsibility to assist those children and their families".

The HSE is now seeking support from the Department of Health to recruit more geneticists and technical staff to meet the expected surge of tests in the coming year, according to sources. In a statement, the HSE said it is working with the Department of Health and the Children's Hospital to "build capacity in the diagnostic pathway".

More than 3,000 women in Ireland are currently taking the medication, from girls as young as eight to 1,700 women of child-bearing age. Licensed as Epilim in Ireland, the drug is prescribed for epilepsy and bipolar. It has long been linked to physical malformations and development issues in children exposed to it in the womb but studies found women were not being told of the risks during pregnancy.

The HSE set up a working group last month, having been warned by a clinical adviser last November that "we have no assurance or certainty" that women were being told about the risks and warned of a "duty of care" to inform them directly.

Letters and information packs were due to be sent to women from last Friday but the process has been delayed to allow follow-up supports, such as a help-line and counselling, to be put in place. Women are also being warned they must not come off the drug unless told to do so by a doctor. Peter Murphy, chief executive of Epilepsy Ireland, said he appreciated that the correct supports had to be put in place before the roll-out but delays put women and children were at further risk.

"A lot of the women who get this letter will already know about it. But there will certainly be a minority of women who will be shocked by this news," he said.

"But for every week that you delay here, there is a chance, albeit small, that one of those women who does not know anything about the risks is going to get pregnant. The more you delay, the more women are potentially at risk of getting pregnant while on this risk and of having no information on what the risks are."

A European Medicines Agency study underlined the link in a study published last year, which found it carried a 10pc risk of causing physical abnormalities in unborn babies and a 40 pc risk of causing problems such as autism.

Families are hoping for an investigation into how women and their children were exposed to the risk.

The Minister for Health, Simon Harris, who met families last March, said he will be writing to the group, Foetal Anticonvulsant Syndrome Forum (FACS) shortly.

A spokesman for the minister said: "A multi-disciplinary project group has been established to build on the work of the HSE valproate response team and this includes work on supports and an information campaign."

Sunday Independent