Risk: Coffee can be as damaging as alcohol

Four cups of coffee a day seriously damage a woman’s chances of having a baby, research suggests.

The effect is almost as bad as the problems in pregnancy caused by alcohol, smoking or being overweight, a fertility conference heard.

Women drinking that much caffeine were 26 per cent less likely to have a baby — adding to evidence that it can harm fertility and the health of an unborn baby.

Earlier this year, it was claimed that just two cups of coffee a day could double the risk of miscarriage. Coffee has also been found to increase the risk of stillbirth and is linked to birth defects.

research has shown fit, young, healthy women take longer to get pregnant if they have lots of caffeinated drinks.

The Dutch researchers followed the health and habits of 9,000 women with fertility problems for up to 13 years after they finished IVF treatment.

Some of the women had a baby through IVF, others had not.

Almost 1,350 had babies after treatment ended, with most pregnancies occurring in the first year.

When the researchers from Radbout University in Nijmegen looked at why some women conceived naturally and others didn’t, they found lifestyle played a critical role.

Those who drank four or more cups of coffee, tea or other caffeinated drinks a day were 26 per cent less likely to have had a baby, the European Society of Human Reproduction and Embryology’s annual conference in Barcelona was told.

Having three or more alcoholic drinks a week had the same effect, while being slightly overweight cut the chances of getting pregnant.

Smoking still appeared to be the most damaging, with more than one cigarette a day cutting the odds by more than a third. 

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Taken together, the four lifestyle factors could have a devastating effect on the chance of pregnancy.

Researcher Dr Bea Lintsen said an infertile overweight 36-year-old who drank at least four cups of coffee a day, smoked more than one cigarette a day and got through least three alcoholic drinks a week had just a five per cent chance of conceiving naturally.

However, if the same woman was of normal weight and lacked all the
vices, the odds would triple to 15 per cent.

She told the conference: ‘We have to remind our patients that they may affect their chance of a spontaneous pregnancy after IVF with a healthy lifestyle.’

Professor Bill Ledger, a leading British fertility doctor, said caffeine is ‘toxic’ to a woman’s eggs and urged would-be mothers to limit their tea and coffee consumption.

The fertility expert from Sheffield University said the study showed simple lifestyle changes may improve the chance of pregnancy after treatment.

He said caffeine, alcohol, smoking and being overweight are all ‘mildly toxic to the ovaries’ but, in the case of those with fertility problems, such habits could really count.

‘Lots of women drink 20 cups of coffee a day and get pregnant falling off a log,’ said Professor Ledger.

‘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.’

The professor of obstetrics and gynaecology added that caffeine could also damage sperm, meaning that men should also think about how much tea or coffee they drink.

‘The American lifestyle of 10 cups of concentrated coffee a day is not the way to be,’ he said.

The British Coffee Association conceded that previous studies had shown a high intake of caffeine delayed conception, but insisted smoking was worse.

Spokesman Zoe Wheeldon said: ‘Scientific evidence demonstrates that for pregnant women or those trying to conceive up to 300mg of caffeine per day is perfectly safe.

‘Our advice is in line with the overwhelming majority of previous research published in this area.’

The Food Standards Agency also recommends an upper limit of 300mg of caffeine a day during pregnancy. However, it is carrying out more research into the issue.