Search

Oocyte development is the end result of a sophisticated biological process that is hormonally regulated and produced by highly specialized cellular lines that differentiate in early embryo/fetal development. Embryo development is initially regulated by maternal transcripts until replaced by embryonic genomic expression. Then, an assortment of hormones and local environmental factors in various concentrations along the reproductive tract (e.g. fallopian tube, endometrial lining) provide the protection, nutrients and means of communication for the embryo to implant and develop. Both oocytes and embryos are susceptible to environmental, occupational and lifestyle exposures that can exert direct toxic effects and disrupt hormones. While some exposures may produce reversible changes, others, especially those damaging germinal cells in utero or during prepuberty, may result in permanent sequelae that continue in future generations. This article reviews the main factors that affect female fertility and their possible influence on human reproduction. Some lifestyles, xeno-oestrogens and heavy metals are already known to compromise female reproductive function. Nonetheless, many questions remain and little is known about the effect of many other factors on female fertility., (Copyright © 2010 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

This article reports a historical study of factors influencing the achievement of clinical preimplantation genetic diagnosis (PGD) in 1990, 22 years after its first demonstration in animals. During the 1970s, research on PGD continued in large farm animals, but serious interest in human PGD was not evident until 1986. First, interest in PGD during the 1970s waned with the advent of prenatal testing, which for gynaecologists was clinically more familiar, technically simpler and ethically less challenging than IVF. Indeed, IVF was viewed with widespread suspicion until the first IVF births in 1978. Second, interest in clinical PGD was stimulated by the UK Parliamentary reaction against human embryo research that greeted the Warnock Report in 1984. This hostility led scientists to initiate a pro-research campaign, further galvanized in 1985 by MP Enoch Powell's bid to ban such research. However, while Powell abhorred embryo research, he approved of PGD, a stance that divided the anti-research lobby. Accordingly, the campaigners for research emphasized that it was needed to achieve PGD. Powell demanded evidence of such projects and PGD research increased from 1986. It is concluded that UK political debates on embryo research played a critical role in stimulating the achievement of clinical PGD. Human pregnancies following preimplantation genetic diagnosis (PGD) for embryo sex were announced in 1990, 22 years after the technique was pioneered in animals. PGD in humans required not only technological advances, such as IVF and sensitive diagnostic tests, but also the motivation to develop and apply them. Our historical analysis shows that, although research on PGD continued in large farm animals during the 1970s, and techniques of the required sensitivity were developed on mouse embryo models, interest in clinical PGD was not evident until 1986. Two factors stimulated this sudden change in motivation. First, interest in PGD was depressed during the 1970s by the advent of prenatal diagnostic techniques, which for gynaecologists were clinically, technically and ethically less challenging than IVF. IVF was then regarded with a suspicion that only started to wane in the early 1980s following the first IVF births. Second, the UK Parliamentary reaction against human embryo research that greeted the Warnock Report in 1984 provided a positive stimulus to clinical PGD by prompting scientists to form a pro-research lobby, which was further galvanized in early 1985 by MP Enoch Powell's almost-successful bid to ban human embryo research. We show that while Powell abhorred embryo research, he approved of PGD, a stance that fractured the unity of the anti-research lobby. Accordingly, the pro-research lobby emphasized that embryo research was needed to achieve PGD. Powell demanded evidence of such projects, thereby, we argue, stimulating PGD research from 1986. Our evidence shows that UK political debates about PGD played a critical role in stimulating the achievement of PGD clinically., (Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

The idea that biomedical research can be influenced by political events implies a teleological basis indicating that scientific achievements occur because there is a political need. Such a concept appears to have been the reason PGD was fast-tracked to emerge as a biomedical achievement well before its due date, occurring at a time when human embryology was still struggling to reach a reasonable level of efficiency and become adopted as a clinically relevant advance around the world. One story underlying the historical achievement of the HFE Act 1990, enabling regulated embryo research, steps outside the firm ground of biomedical science and encourages the idea that Reproductive BioMedicine Online should embrace a further section enabling articles dealing with 'History, politics and personalities' where these influence biomedical research., (Copyright © 2011 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)