Originally Posted by birthjunkie27
I've just been trying to avoid caffeine in general....even though I know it's "ok" to have 1-2 cups of java a day....I'm paranoid about what I put in my body. My Bradley instructor (from first pregnancy) once put it like this: If mom weighs 140 lbs and baby weighs 7 lbs (which it doesn't yet...I think
) then baby receives the equivalent of 20x what mom consumes.
That really freaked me out....now I don't know how much of it baby actually gets....but still. Freaky nonetheless.
Ok, that's really bad logic.
First off, the baby also has 1/20 the amount of blood. So by the logic your Bradley teacher gave you, the baby would be getting approximately the same effect as you are. HOWEVER, not all chemicals cross the placenta in the same proportion they are in your blood. Some preferentially cross the placenta giving the baby a relative higher concentration, and some chemicals are filtered out by the placenta, giving th ebaby a significatly lower relative dose. I have no idea where caffeine sits with this, though.
I have read that the half-life (time for the concentration to drop to half maximum) of caffeine in an adult system is something 5-8 hours, but is significantly longer in the baby. This is all relative
to the peak concentration in the individual though, and says nothing about how much actually
reaches the baby.
The recommendation of 1-2 cups of coffee per day is based on a french study showing no ill effects from up to 6 cups a day.
All that being said, yeah, I avoid caffeine in large quantities, but when it's hot out, nothing's better than a cup of iced tea.