Leigh-Ann Mulcahy QC

Leigh-Ann Mulcahy KC led Robert Dickason (of Outer Temple Chambers) in acting for the Secretary of State for Health and Social Care in litigation arising from the use of hormonal pregnancy test (HPT) tablets taken to diagnose pregnancy in the 1950s-1970s.

In this group litigation, over 200 claims were issued against the pharmaceutical manufacturers of two HPTs (Primodos and Amenorone Forte), as well as against the Government on the basis that it was responsible for safe regulation of HPTs in the 1950s-1970s. The claimants maintained that HPTs taken during pregnancy had caused them to suffer congenital malformations, miscarriage and/or stillbirth.

Previous litigation brought in the 1970s-1980s had also sought to prove that HPTs caused congenital malformations but had to be discontinued in 1982 shortly before trial on the basis that there was no real prospect of proving causation.

The synthetic hormones contained in HPTs remain in widespread use internationally, including for the treatment of gynaecological conditions and as part of the combined oral contraceptive pill. Any indication that these hormones could be unsafe in pregnancy would be of profound importance in modern medicine. However, a detailed review by the Commission on Human Medicines between 2015 and 2017 concluded that the available scientific evidence did not support a causal association between HPT use and adverse outcomes in pregnancy, see here for the full report.

Following service of Generic Particulars of Claim, the defendants applied to strike out the claims, contending that the claimants had no real prospect of proving that HPTs had caused the range of injuries alleged, contrary to the conclusions reached by the Commission on Human Medicines. Notwithstanding the developments in science and medicine in the intervening decades, the claimants were no more able to prove causation today than they were in 1982.

On 26 May 2023, following a 4-day hearing, the High Court granted the defendants’ applications and struck out the claims. Mrs Justice Yip concluded that, on all the evidence before her, the claimants had been unable to demonstrate an arguable case on causation and hence that it would be an abuse of process to permit the litigation to continue. A link to the judgment is here.