More than a third of British women in their 20s smoke, and the rate, despite aggressive campaigns against smoking, has only decreased slightly in the past five years. One in seven couples experience problems conceiving, and, in cases involving female infertility, no specific cause can be found in 20 per cent of cases.
According to a study in Human Reproduction by Dutch researchers who looked at success rates of in-vitro fertilisation (IVF) procedures in more than 8,000 women, smoking has a devastating impact on a woman's chance of conceiving with fertility treatment, and women in their 20s and 30s who are finding it difficult to get pregnant, are adding 10 years to their reproductive age if they smoke. If they do conceive, women who smoke are more likely to suffer a miscarriage.
The women, whose average was 32, were all starting their first cycle of IVF treatment, some had been diagnosed with a specific problem, but many had unexplainable trouble conceiving.
Of the women in the study, forty three per cent were smokers who continued to smoke throughout their fertility treatment. It was found that the live birth rate among women who smoked was 28 per cent lower than the overall average.Compared with 20 per cent of the non-smokers, only 13 per cent of the smokers had a live birth. The impact of smoking on successful IVF treatment was most apparent among women who had unexplained fertility problems. About 21 per cent lost their babies, compared with 16 per cent of non-smokers.
Professor Didi Braat from Radboud University Nijmegen Medical Centre, one of the study authors, says that smoking has a devastating impact and is comparable to adding a decade to the reproductive age of a 20-year-old.
The chances of having an IVF baby are also seriously reduced by being excessively overweight, although women who were slightly fatter than normal were more likely to be successful. The birth rate also fell by 2 per cent for every year in age of the women involved in the study.
The researchers said that women undergoing fertility treatment could massively improve their chances of having a baby if they did not smoke and were of normal weight.
The chairwoman of the British Fertility Society, Professor Alison Murdoch, who is also the head of reproductive medicine at the Newcastle Centre for Life, says there is evidence people who smoke have impaired conception, and they should be advised to quit smoking.