Two doctors who run a clinic dealing with gestational diabetes have warned that pregnant women and their unborn babies are being put at risk because some patients cannot afford to pay for medication for the condition.

Professor Sean Daly, an obstetrician at the Coombe hospital, and Professor Brendan Kinsley, an endocrinologist from the Mater Hospital, were speaking to RTÉ's Morning Edition about the situation.

Professor Daly said many of their patients, who were working and were not eligible for a medical card, were not able to afford the cost of the medication and were therefore not taking it.

The professors say they have written to the Health Service Executive and the Department of Health about the issue.

Professor Daly said they believe there was an unacceptable risk now being put on these pregnancies and an unacceptable burden being put on these women.

He said: "There is a Drugs Payments Scheme which will cover you for any medications above €144 a month.

"But it's the first €144 a month that some of our patients are really struggling with.

"And these are patients who aren't eligible for a medical card, who have a job, and suddenly find themselves having to pay out €144, and in essence many of them aren't able to do it and aren't doing it."