|
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."
Zoe Wheeldon from the British Coffee Association said the latest
research, although well designed and robust, did not change
the current Food Standards Agency recommendation of a safe
upper
limit of 300mg of caffeine per day for pregnant women. "This evidence
must be reviewed in conjunction with existing research and it is
important to review all the available data rather than taking one
study in isolation."
A spokesman from the Food Standards Agency said: "In order
to provide a more robust basis for the FSA's advice to pregnant
women on caffeine consumption, an FSA-funded study, involving around
2,500 pregnant women, was commissioned in 2003. This is almost
complete and the results will be presented to the Committee On
Toxicity in closed session for consideration. We will ask the committee
to also look at this new American study. When the committee has
reached conclusions the agency will, if appropriate, revise its
advice on caffeine consumption in pregnancy."
BBC NEWS
|