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Passive Smoking Puts Pregnancy on Hold

29 September 2000

The University of Bristol has unveiled dramatic new research results which demonstrate for the first time that female fertility is reduced by passive smoking.

The University of Bristol has unveiled dramatic new research results at Exploreƒ today, Friday 29 September, which demonstrate for the first time that female fertility is reduced by passive smoking.

The findings have serious implications for couples trying to start a family: even if the female is a non-smoker her chances of conceiving within 12 months are significantly reduced if her partner smokes at home.

The findings were announced by University researchers Christopher Ford and Kate North who are part of the team responsible for the Avon Longitudinal Study of Pregnancy and Childhood, informally known as the ‘Children of the Nineties’ project. The study also found that male fertility is reduced where the man is an active smoker. The full research will be published worldwide in the October edition of Fertility and Sterility journal, published by the American Society for Reproductive Medicine.

By using a large population base of 8,500 couples and tracking the time it took them to conceive, the University of Bristol research team was able to confirm that passive smoking by the female reduces the likelihood of conceiving within twelve months, independent of other factors such as age, obesity and education.

If, for example, a non-smoking woman is exposed to passive smoke in the workplace or at home, the odds of her taking more than 12 months to conceive increase by 14 per cent. If her partner smokes more than 20 cigarettes a day the odds of delayed conception are increased by a staggering 34 per cent. This scenario is made worse by the separate finding that men who smoke are likely to be less fertile than men who do not.

In line with previous observations, the study also proved that where the female is an active tobacco smoker, the odds of her taking more than12 months to conceive are increased by more than 50 per cent.

Christopher Ford said; “It has been known for many years that women who smoke whilst trying to get pregnant decrease their chances of conceiving. The results of our study provide more compelling reasons for couples trying to start a family to give up smoking themselves and avoid public places where smoking is allowed”.

Prior to the research findings becoming public, scientists at Exploreƒ – the new science centre on Bristol’s rejuvenated Harbourside – teamed up with ’Children of the Nineties’ researchers to counsel public opinion on smoking in public. The aim was to find out whether more people would ban smoking in public places if they knew passive smoking had an impact on female fertility.

From a sample base of more than two hundred Explore visitors, Dr Kathy Sykes, ƒ’s senior science consultant discovered that 80 per cent would favour a ban on smoking in public places if it had a proven negative impact on female fertility. This compares to 70 per cent who would favour a similar ban if the impact on female fertility could not be proved. On balance, more women than men favoured the ban if passive smoking reduced female fertility and this was particularly noticeable among the Under 25s where 78 per cent of females questioned supported a ban, compared to just 38 per cent of men.


Academic paper reference:

“Fertility and active and passive smoking”. MGR Hull, K North, H Taylor, A Farrow, WCL Ford, J Golding and the ALSPAC Study Team. Fertility and Sterility 2000; 74 (4): 725-733. doi: 10.1016/S0015-0282(00)01501-6

Notes to editors:

Explore is part of ƒ, a £97 million Millennium Landmark project and world-class visitor destination on Bristol’s revitalised Harbourside. ƒ opened to the public this summer and includes Wildscreenƒ – a breathtaking journey through the natural world – and the West’s first IMAX® Theatre. Further information about ƒ is available on 0117 915 5000 or at


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