Interesting facts you'd rather not know: Fetal Urination

I learned the other day that fetuses urinate in the womb. Apparently the amniotic fluid is primarily composed of fetal urine (after 11-12 weeks), which is swallowed and re-urinated by the fetus. Luckily for the mother (and the fetus, I guess) this urine is totally different from normal urine. Still, this makes me glad I'll never be pregnant.