A study released this week has confirmed that caffeine intake in the first trimester of pregnancy increases the chance of early miscarriage. Most naturopaths advise women planning to become pregnant to stop drinking caffeine related drinks, especially coffee, and to resist drinking it again til after they have ceased breastfeeding. Yet conventional medicine has continued to declare that up to 300 mg of caffeine a day in pregnancy does no harm. While American literature equates this to 4 cups of coffee a day, it would be closer to 2 decent cups from a Melbourne barista.
But now a study published in the American Journal of Obstetrics and Gynaecology has found more than 200mg of caffeine a day doubled the risk compared to abstainers. That means just half the presumed ‘safe’ intake of caffeine doubles the chance of a miscarriage in the first 12 weeks of pregnancy.
Coffee ‘raises miscarriage risk’
Pregnant women should consider avoiding caffeine, say researchers who found even moderate consumption in early pregnancy raises the miscarriage risk.
Currently, the Food Standards Agency sets an upper limit during pregnancy of 300mg – or four cups of coffee a day.
But an American Journal of Obstetrics and Gynaecology study found more than 200mg of caffeine a day doubled the risk compared to abstainers.
Experts said they would review the data to see if advice needed changing.
Women probably should consider stopping caffeine consumption during pregnancy. Study author Dr Li
Pat O’Brien, consultant obstetrician and spokesman for the Royal College of Obstetricians and Gynaecologists, said based on the findings he would now be advising women in their first 12 weeks of pregnancy to abstain from caffeine altogether.
“The first 12 weeks is a very vulnerable time for the baby. It’s when most miscarriages occur,” he explained.
He said most women in early pregnancy went off the taste of caffeinated drinks anyway and so should not find abstaining from them too difficult.
But he said it was unclear whether pregnant women needed to avoid caffeine in later pregnancy.
An estimated one in five pregnancies in the UK will end in miscarriage, affecting around 250,000 women in the UK every year.
There are a number of well-established risk factors, such as increased maternal age, a previous history of miscarriage, and infertility.
But the causes of the majority of miscarriages are not fully understood.
Caffeine has been mooted as a risk factor before, but studies have yielded conflicting results.
For the latest research, Dr De-Kun Li and colleagues at the Kaiser Permanente Division of Research, studied 1,063 women who had become pregnant in the last month or two.
300 mg of caffeine is roughly equivalent to:
Four average cups or three average mugs of instant coffee
Three average cups of brewed coffee
Six average cups of tea
Eight cans of regular cola drinks
Four cans of so-called “energy” drinks
400g (eight standard 50g bars) of normal chocolate
Caffeine content in a cup of tea or coffee varies by different brands and brewing methods
Source: Food Standards Agency
They asked the women to provide a detailed diary about their caffeine intake up to their 20th week of pregnancy.
When they compared this information with how many of the women had miscarried by 20 weeks gestation, 172 of the women in total, they found a link.
Compared with non-users, women who consumed up to 200mg of caffeine a day had an increased risk of miscarriage – 15% versus 12%.
For women who drank more than 200mg, the risk increased to 25%.
The increased risk appeared to be related to the caffeine itself, rather than other coffee ingredients because other caffeinated beverages such as tea and hot chocolate showed a similar trend to coffee.
Caffeine is able to cross the placenta to the foetus, but it is not clear what affect this has on the growing baby.
Dr Li said: “The main message for pregnant women from these findings is that they probably should consider stopping caffeine consumption during pregnancy.”
Story from BBC NEWS:
Published: 2008/01/21 05:06:05 GMT