system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are baby's urine and feces kept contained while in the womb?
gpt
Urine is excreted out into the amniotic fluid and swallowed by the baby. no big deal, it's as sterile as can be, and metabolic wastes are also removed via the placenta.

Baby poop stays in the colon, the baby's first poop is a weird,black, gooey substance called *meconium*, normally they will have their first poop of this meconium after birth, but pooping before or during birth can be a medical emergency due to contamination.