There was a tremendous amount of distress caused to all women

British Pregnancy Advisory Service

The relative safety of the "third generation" contraceptive pill has been debated at length by scientists over the past five years.

In October 1995, the UK Committee on the Safety of Medicines (CSM) in response to three separate research projects, warned doctors and pharmacists that taking the "third generation" pills doubled the risk of venous thromboembolism (VTE).

This is the formation of blood clots in the deep veins of the legs or pelvis, a painful condition, which is fatal in a handful of cases if the clot moves inside the circulatory system and lodges somewhere like the lungs.

After the 1995 scare many thousands of women either changed their pill type, or stopped taking oral contraceptives altogether.

The change is credited with a 8% rise in the number of abortions in the following year, equating to approximately 13,000 abortions.

In addition, there were only slightly fewer unwanted pregnancies which were not aborted, say experts.

Double the risk

Although the risk of VTE rises slightly with any sort of contraceptive pill - more so with the third generation pills - the overall chances of VTE are greater during pregnancy that when taking any sort of contraceptive pill.

The latest research adds weight to the opinion that third generation pills carry twice the risk of VTE of other contraceptive pills.

But the researchers' rough calculation is that the 1995 scare probably prevented a handful of cases of VTE in the 360,000 women who had been taking third generation pills.

A spokesman for the British Pregnancy Advisory Service, which offers information on termination and unwanted pregnancy, said the main lesson to be learned concerned the sensitive handling of information about risks of this sort.

She said: "There was a tremendous amount of distress caused to all women, not just those on the third generation pills, by the way the message was put out.

"We hope that everyone has taken on board very carefully how issues of safety have to be handled in future.

"The pill is incredibly safe if people want to protect themselves against unwanted pregnancy."

The research was published in the British Medical Journal.