17 December 2012
ByAppeared in BioNews 686
The fourth session the Progress Educational Trust's annual conference for 2012 'Fertility Treatment: A Life-Changing Event?' continued the day's critical perspective on the evidential basis for the impact of lifestyle factors on the outcome of fertility treatment and resulting children. This time it was the impact of alcohol and smoking that came under scrutiny. Can the evidential link be made between these lifestyle choices and poorer fertility outcomes or children's health?
Jean Golding, professor of paediatric and perinatal epidemiology at the University of Bristol, said data collected from its Avon Longitudinal Study of Parents and Children showed that the time taken to conceive among those recruited increased if either the man or the woman smokes, among other risks.
Interestingly, Professor Golding has also begun to look at the effects of smoking on future generations. The researchers observed how smoking may affect daughters' fertility by comparing grandmothers who smoked and mothers who did not, with grandmothers and mothers who both did not smoke. Initial results showed a difference in birth weight and length for boys, with no difference seen for girls.
These results identify smoking as a risk factor – but what about alcohol? Guidance on lifestyle factors given to people undergoing fertility treatment is not limited to smoking. The current NICE, National Institute for Health and Clinical Excellence, guideline on fertility, which is in the process of being updated, advises on the risks of smoking, drinking alcohol, wearing tight underwear, body weight, recreational drug use and even being involved in hazardous occupations.
Yet for all the concern, the evidential basis remains unclear. Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said that his studies did not show smoking and alcohol had an effect of the quality of sperm. Reviewing some of the studies on sperm andrology – many of which were underpowered and poorly controlled, he said – the evidence was not conclusive.
Part of the problem he explained was of a lack of robust scientific evidence about the many known and unknown causes of infertility and a poor understanding of sperm andrology. He explained that the quality of sperm and infertility were not the same and although studies can be cited to indicate that smokers demonstrate higher DNA damage in their sperm, or that consuming alcohol makes a difference based on certain parameters measuring semen quality. More research is needed.
Dr Pacey concluded there is very little a man can do in terms of lifestyle about risks to fertility. Few lifestyle factors, in fact, have a negative effect of motility or sperm concentration. Testicles are 'robust', he said.
Professor Neil McClure of Queen's University Belfast reflected on the inconclusiveness of current data. He emphasised that a man's sperm count is extremely variable and can change all the time, which is just one limitation to producing quality research. Furthermore, as sperm is mostly taken from fertility patients attending clinics, it has already been through a filtering process so may not be a representative sample of the general male population.
Professor McClure also pointed out that controlling for lifestyle factors is very difficult – what are the chances of finding men who don't drink, don't smoke, don't wear tight underwear, don't use laptops…and so on? His conclusion is that there is data that supports the view that smoking is probably bad for fertility but on alcohol it is totally unclear.
Dr Ellie Lee, a reader in social policy and director of the Centre for Parenting Culture Studies at the University of Kent, argued that some Government guidance – for example, for pregnant women to avoid drinking alcohol altogether – is not based on science. Instead, she identifies a shift in political culture towards risk aversion, which has been promoted by some sections of the media and the medical profession.
Dr Lee identifies examples of risk reporting in the media (which has latterly moved from a sceptical to a more risk-averse position) but also places blame on some researchers who feel the need to feed strong lines to the media. The words 'can' and 'effect' emphasises risk, she says, giving the example of a quote from a recent study (coauthored by Jean Golding) that linked moderate alcohol during pregnancy to a child's IQ. Even though an effect may be very small, on the basis of a theoretical risk the message becomes take no risk.
For Dr Lee, it is unreasonable to prohibit activities in people's private lives. She highlighted how every mother wants to do the best for her children and will probably follow Government advice. Can we blame them? But sending out strong public messages not supported by evidence is not only risk averse, said Dr Lee, but is misleading and can promote fear. Fertility patients already experience high levels of stress and emotional disturbance (the topic of an earlier session, see BioNews 684).
There were a number of important messages that emerged from this session, notably the need for well-designed studies to provide robust evidence. Another theme was that people should be educated at a young age about potentially harmful lifestyle behaviour (advocated by Professor Golding and Dr Pacey) – this also remains true outside the fertility context.
The session also raised the prospect that the connection between lifestyle and fertility is perhaps not one that can be 'proved' to a satisfactory extent. Indeed, should we be even telling fertility patients what to do? Either way the Government seems intent on introducing policy in this area.
Perhaps what is needed, rather than more studies producing even more data, is a change in our attitudes towards risk. Dr Lee thinks the Government should stay out of it; Professor McClure thinks the health agenda has been hijacked by the press and the Government is being reactive, rather than proactive. Such views serve to promote necessary debate on the merits and gaps in current scientific understanding, which perhaps needs to be opened up to greater public scrutiny.
PET is grateful to the conference's gold sponsors, Merck Serono, silver sponsors London Women's Clinic and bronze sponsors Ferring Pharmaceuticals.