Lelia Duley, who died on 10 December 2025, led the Collaborative Eclampsia Study, one of the most important randomised trials ever conducted.
Most trials demonstrate, at best, small benefits in the elderly and are often slowly implemented. Trials in the young often concern uncommon diseases. But in 1995 the Eclampsia Trial not only showed that magnesium sulphate halved maternal deaths from this common condition but was implemented almost overnight. Worldwide, it may still prevent about 50,000 maternal mortalities annually.
Born in Oxford in 1958, Prof Duley qualified from the university of Aberdeen in 1981. She trained in obstetrics and gynaecology in Nottingham and Oxford, gaining her MRCOG in 1988, and the following year took up a Wellcome Trust Fellowship at the National Perinatal Epidemiology Unit. Her supervisor was Iain Chalmers and her research project, which formed the basis of her MD thesis, was the Eclampsia Trial, published in the Lancet in 1995.
With typical modesty, Lelia was an early adopter of the policy of authoring her major publications with the name of the study group in recognition of the collaborative effort involved. Her MAGPIE trial was not only by far the largest trial in pregnancy at that time (over 10,000 participants) but by following up over 99% of participants set a pattern for excellence that few later trials achieve.
Delaying cord clamping almost halves mortality for preterm babies. Lelia led the UK-CORD trial, her leadership and professional oversight of the trial ensured that effective outcomes and data, vital to the success of the trial, were collected. Aspirin prevents pre-eclampsia, but conventional systematic reviews had failed to convince guideline authors - many previous trials were of limited success, and the effect size was small - until Lelia, with her colleague Lisa Askie, led the PARIS group in a huge individual patient data meta-analysis.
Lelia was Deputy Director of the UK Cochrane Centre, and the author of countless reviews for the Cochrane Pregnancy and Childbirth Group. In 2006 she moved to Leeds as Professor of Obstetric Epidemiology, and in 2011 to Nottingham as Professor of Clinical Trials Research, and Director of the Nottingham Clinical Trials Unit.
She took early retirement in 2016; she had been suffering from chronic lymphocytic leukaemia for some time, and the prognosis was poor. She enthusiastically participated in CLL Support, a patient-led charity for people affected by leukaemia, and joined several trial steering committees as a quietly influential patient advisor.
Unsurprisingly, when she herself fitted the recruitment criteria, she also participated. In at least one open trial, she was randomly allocated to the no treatment group, and she was content with that. The trial was well designed, and the active treatment might be harmful. In prospect participants were likely to do better than non-participants. It was probably not coincidental that she far outlived her initial prognosis.
She is survived by her husband Clive Adams, their two children, Lucy and Beth, and two brothers Steven and Chris. Her sister Clare predeceased her.
Professor Jim Thornton