This seems to be more about caffeine than coffee.
In 2008, due to this study that suggested that caffeine intake during pregnancy could increase the risk of fetal growth restriction, the "UK Government's Food Standards Agency" issued new advice to pregnant women on daily caffeine consumption:
Pregnant women are being advised to
limit their daily caffeine intake,
ideally keeping this below 200mg a day
(previously it was 300mg). This is
roughly two mugs of coffee a day,
although caffeine is also present in
tea, chocolate, some soft drinks, and
Too much caffeine might result in a
baby having a lower birth weight than
it should, which can increase the risk
of some health conditions for the baby
in later life, or could possibly
result in spontaneous miscarriage.
We would emphasise that the risks are
likely to be very small and believe
our new advice, which is based on new
research and has been considered by
leading independent scientists, is
sensible and proportionate.
As stated above, caffeine isn't just in coffee, it can also be found in (ice-)tea, soft and energy drinks, cocoa and chocolate. I'd guess these sources for caffeine are more common for children than coffee.
Here is a list of caffeinated beverages (including the amount of caffeine in it).
BabyCenter has this to say:
No. Caffeine has plenty of undesirable
effects, but interfering with a
child's growth isn't one of them.
The United States hasn't established
recommended limits for kids' caffeine
consumption. In Canada, it's
recommended that kids ages 4 to 6 get
no more than 45 mg a day, kids ages 7
to 9 get no more than 62.5 mg, and
kids ages 10 to 12 get no more than 85