Scientists looking at pregnancy rates in women who have previously had IVF treatment say that lifestyle factors play a large part in whether a woman will go on to achieve a natural pregnancy or not. Speaking at the annual meeting of the European Society of Human Reproduction and Embryology (ESHRE) in Barcelona, Dr Ame Lintsen, from Radboud University in Nijmegen, the Netherlands, said that maintaining a healthy lifestyle after IVF treatment maximized the chances of a subsequent natural pregnancy.
The research team found all women who had undergone IVF treatment in the Netherlands between 1983 and 1995 (in the OMEA project) and asked them to answer a questionnaire on their lifestyle and reproductive history; 8669 women responded to the survey. The scientists were looking to find out the rate of the first natural conception after cessation of IVF treatment according to a woman's maternal age, pregnancy history, duration and cause of subfertility, the number of IVF cycles previously attempted, Body Mass Index, smoking and alcohol and caffeine intake. They found distinct patterns in the rate of subsequent pregnancies and the lifestyle of the women concerned.
The researchers found that 1349 of the women (16 per cent) had conceived naturally after stopping IVF treatment (in a maximum timeframe of 13 years). Forty-five per cent of these had conceived within 6 months after their last IVF cycle. However, they also discovered that smoking more than one cigarette a day made a woman 44 per cent less likely than average to conceive naturally; drinking more than four cups of coffee (or other caffeine drinks) a day made a woman 26 per cent less likely to do so, consuming alcohol on more than three occasions per week made her 26 per cent less likely to conceive and being significantly overweight reduced the chances of a subsequent natural conception by 29 per cent.
Similarly, increasing maternal age and having had more than four previous IVF attempts also appeared to reduce the chances of a subsequent natural conception, said the researchers, as did the original cause of a woman's subfertility. If this was due to uterine, cervical or ovarian problems or subfertility in their male partners, the women had a significantly greater chance of achieving a successful natural pregnancy after stopping IVF. However, if the woman's subfertility was 'unexplained' or the problem was with tubal pathology, her chances of a natural pregnancy greatly decreased.
Commenting on the findings, Dr Lintsen said that the results showed that 'women can influence their natural fecundity with healthy lifestyle choices'. Professor Bill Ledger, Professor of Obstetrics and Gynecology at Sheffield University in the UK, said that 'lots of women drink 20 cups of coffee a day and get pregnant falling off a log'. But, he added, 'it doesn't have a massive effect, but if you are already infertile, it could just tip you over the edge. You don't have to stop, just drink less'.