London - Thousands of pregnant women taking prescription drugs for asthma, epilepsy, diabetes and depression are at the centre of a major inquiry into birth defects and health problems in babies.

Asthma inhalers, man-made insulin, new anti-epileptics and Prozac-style anti-depressants called SSRIs, are being probed in the Europe-wide study of nearly four million births.

Pregnant women with long-term conditions have no choice but to take their medicines, and around one in five expectant mothers suffer from depression which could require treatment.

Last night, the Royal College of Obstetricians and Gynaecologists urged women to keep taking their medication in spite of the investigation, and to talk to their doctor if worried.

In the Euromedicat study, due to be published next year, medical records are being matched with national registers of congenital abnormalities in newborns, including cleft palate, spina bifida and heart defects.

Scientific co-ordinator Dr Marian Bakker, of the University Medical Centre in Groningen, in the Netherlands, said: “It is very important work because for many drugs, the safety evidence has not been established yet. We are absolutely not saying to women to avoid all drugs during pregnancy but it should be very carefully weighed up because it is very difficult to establish safety in pregnancy.”

A number of scientific studies have already pointed to links between prescription drugs and birth defects or health problems.

Preventative asthma inhalers, which contain steroids, have recently been linked to a slightly increased risk of hormonal and metabolic disorders in babies.

Doctors writing in the American Journal of Respiratory and Critical Care Medicine said using budesonide, fluticasone and beclomethasone inhalers warranted further investigation.

Consultant Patrick O’Brien, of the Royal College of Obstetricians and Gynaecologists, said: “Since the Thalidomide disaster everyone thinks twice about taking medicines during pregnancy. It is, however, about balancing the risks of the medicine with the benefits.”

Leanne Metcalf, of Asthma UK, said: “The national clinical guidelines are that inhalers are safe in pregnancy and we support that. We don’t want women to stop taking their medication.” - Daily Mail