This sac protects the developing fetus,
and it slowly fills with
amniotic fluid and swells as the fetus grows. Initially, the mother's body provides the source of liquid, but over time, much of the fluid is fetal in origin. By the end of the pregnancy, a lot of the amniotic fluid is in fact urine generated by the developing fetus. I dont know if that helps at all sorry , but yes amniotic fluid can vary by your fluid intake .