I was reading an [article][1] saying that fetuses urinate into the amniotic fluid. It also mentioned that, because we drink the amniotic fluid, we’ve been drinking our pee for months.

However, why do we produce urine as fetuses? I believed the placenta was our source of waste removal; why would we have any need for filtering blood through our own kidneys?

In addition, why would we drink the amniotic fluid? Is there a benefit to doing that?

  [1]: http://mentalfloss.com/article/53732/do-fetuses-go-bathroom-womb