Coffee and the pregnant woman

What do you drink? Starbucks? Dunkin' Donuts? A brew you make at home from hand-picked Sumatran medium roast that you ground fresh? A half-pot of Folgers?

Or maybe you don't drink coffee. Maybe you drink tea. Or Coke Zero? Or even - shudder - Mountain Dew?

You wouldn't by any chance happen to be... pregnant?

Review: A bit dry & academic, but informative.
Guess what? According to The World of Caffeine, the normal habits of consumption you established back before you had a rapidly growing abdominal parasite sucking away your calcium, iron and general vitality just might be kicking your ass right now.

Under normal circumstances, that cup of caffeinated deliciousness you had a breakfast is pretty much metabolized away by bedtime. The half-life for caffeine is about 3.5 hours; it says so, right on page 222. So what does that mean?

Example: your usual cup of Starbucks's Pumpkin Spice Caramel Cinnamon Sugarbomb Latte that you drank at 8:00 a.m. had 200 mg of caffeine. By 11:30, only 100 mg is left in your body. By 3:00, it's down to 50 mg, and at 6:30, only 25 mg remain. When you're ready to crawl into bed at 10:00 p.m. after a long day of being a non-pregnant woman, you've only got about 12.5 mg left in you, only as much as in some decaffeinated coffees. (If you've been drinking coffee through the day, you can run the numbers for yourself, you addict.)

But if you're pregnant? You're in trouble.

The half-life for caffeine in a pregnant woman is more like 18 hours. Thank you, hormones! Drink your normal 8:00 cup with 200 mg of caffeine and you'll still have something like 175 mg floating around in your body at your 10:00 p.m. bedtime. And if you've been adding caffeine during the day as usual, it all accumulates instead of being cleared normally. At bedtime, you've got every cup you drank that day still buzzing you. No wonder you have trouble sleeping!

Your mileage may vary, but science don't lie. Take care of yourselves, ladies.

This public service message brought to you by a guy who has seen pregnancy combined with sleep deprivation.



  1. Not to mention the kid gets some too. Mrs. Fetched accidentally drank some caff'ed tea when pregnant with The Boy, and he spent much of the night slam-dancing and turning somersaults. That helps keep everyone awake.

  2. The book says the half-life for caffeine in infants is 200 hours. That's DAYS and DAYS of hopping and bopping in there.

  3. Tony,

    That's fascinating to think of caffeine as being more akin to radiation than food. I did a paper in High School on caffeine and while I caught the 3.5 hours, I didn't realize that that was a half-life. So the times when I've had a lot of caffeine I was always surprised that, even well more than four hours later, I STILL couldn't sleep.

    Good to know.

    Also, back in the day when work saw all nighters, or at least late nights, fairly often, I deliberatley avoided caffeine as a regular thing so it would have actual potency on days when it was needed.

    All the best,

