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发表于 2014-5-14 04:52:28
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Do unborn babies pee and/or defecate in the womb?
That's two questions, so two answers. Number one: yes, and it's a good thing they do. Number two: yes, but you better hope they don't.
Fetal urination is normal. It's part of that "miracle of life" folderol the nature programs exalt just before they hit you with something you'd rather not know. Naturally, fetal urine isn't quite the same as yours or mine. It does contain urea, but much of the nitrogenous waste enters maternal circulation for mama to clean up. Fetal urine isn't yellow, either. Fetuses and newborns lack enzymes to convert bile pigments to urobilin, which colors the output of older children and adults.
Urine production begins late in the first trimester, about the same time the two-inch embryo becomes a fetus. In the second half of pregnancy, fetal urine is an important constituent of amniotic fluid. By the time the kid is about ready to pop out, he or she is passing roughly a liter a day. Where does it go? Seems kids learn the benefits of recycling early on — they swallow it. They'd better, too, lest polyhydramnios (a potentially dangerous buildup of fluid volume) result. When fetal urination is impaired, the opposite complication, oligohydramnios, usually occurs.
[ 本帖最后由 粉猪妈妈 于 2010-12-13 21:36 编辑 ] |
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