UK litigation over side effects of the third generation contraceptive pills reaches a crunch point this month, when the High Court judge overseeing the case must decide whether or not the risk of venous thromboembolism from the newer pills is more than twice as high as for the second generation of oral contraceptives.

Mr Justice Mackay will rule on the issue at the end of May, after submissions from both sides, based on expert evidence, finished this week. If the judge decides the relative risk is “2.0, the compensation claim by more than 100 women against three manufacturers will be halted in its tracks. The claim will be thrown out because the women will have failed to prove that their venous thromboembolism was more likely than not to have been caused by taking a third generation pill.

The women launched their action under the Consumer Protection Act 1987, claiming that the third generation pills were defective products because there was no warning that they carried higher risks than their older counterparts.

The claims are against Schering Healthcare (manufacturer of Femodene), Wyeth (Minulet and Tri-Minulet), and Organon Laboratories (Marvelon and Mercilon). The new pills captured a large share of the UK market before the 1995 “pill scare,” when their use dropped dramatically after …