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Dr Allan Pacey

Key Areas of Expertise:

Human fertility and reproduction

Male fertility and semen quality

Semen mobility

Dr Allan Pacey is a senior lecturer in Andrology at the University of Sheffield, and specialises in the field of human fertility.

Dr Pacey was awarded his PhD in 1991 from the University of St. Andrews after which he undertook a one-year Research Fellowship funded by the Royal Society at the Station Zoologique, Villefrance-sur-Mer, France.

He joined the University of Sheffield in 1992, first as a Postdoctoral Research Assistant and then was appointed as lecturer in 1997. In 2001 he was appointed as Senior Lecturer in Andrology.

In addition to his academic duties, he is also the Head of Andrology for Sheffield Teaching Hospitals where he directs a busy clinical andrology laboratory and is in charge of the sperm banking service.

Research Interests

He is interested in the biology of human spermatozoa and aspects of semen quality and fertility in males. It is estimated that 1 in 6 couples have a problem in conceiving a child and in about half of these cases, a problem is identified with the male partner. This may be a result of too few sperm being produced, or the fact that sperm have poor motility (swimming ability) or morphology (size and shape).

In recent years, his research has focussed on how micro-organisms such as Chlamydia trachomatis interact with sperm and affect sperm function. This is in collaboration with Adrian Eley and has shown that the bacteria can trigger signalling pathways in sperm that lead to premature sperm death. We have investigated the molecular nature of this process and have recently shown that sperm washing methods currently in use in clinics are not effective in removing C. trachomatis from sperm.

In the search for better diagnostic methods in the clinic, he has recently collaborated with engineers from the University of Glasgow (Green/Gilles) and applied modelling techniques used in fluid mechanics to better understand how sperm swim. This paper was published in the Journal of Fluid Mechanics in 2008 and shows that swimming speed is closely related to the side and shape of the sperm head.

Work with Urologists in Sheffield has developed a new diagnostic test for men who have small numbers of non-motile sperm in their ejaculates following vasectomy. In some men, these sperm are present for many months or years meaning the men cannot be discharged from care or cease using contraception because it is not certain if the surgery has been successful. The team have employed a fluorescent test that allows them to determine if these sperm are dead or alive in order to discriminate between failed vasectomy and inadequate clearance of dead sperm.

He is interested in occupational and environmental influences on semen quality. In collaboration with colleagues from the University of Manchester, he conducted a large multi-centre study of semen quality at 14 clinics within the UK, relating measures of semen quality to. In 2008 they published the first paper describing how occupational exposure to glycol ethers (found in paints) was associated with a low motile sperm count. Further papers from this data are being prepared and will be published shortly.

Current Projects

  • Immediate and longer-term consequences for men who bank sperm prior to cancer treatment.
  • Trans-national reproduction: an exploratory study of UK residents who travel abroad for fertility treatment.
  • A pilot study to investigate the interaction between cytomegalovirus (CMV) infection and human spermatozoa.

Contact Details

Dr Allan Pacey BSc, PhD Department of Human Metabolism Academic Unit of Reproductive and Developmental Medicine Level 4, The Jessop Wing Sheffield S10 2SF UK Office: JW4 04

Tel: +44 (0) 114 226 8290

Fax: +44 (0) 114 226 1074


For further details please visit: Dr Allan Pacey