Fluid retention typically comes late in pregnancy. It is the way your body prepares for delivery. A lot of fluid will leave your body at the time of delivery between the amniotic fluid, and the placenta separating from your uterus. The body stores extra fluid in preparation for this. After you deliver, your body gets rid of the fluid and you will experience frequent urination at that time. It’s important to stay hydrated during pregnancy. Drink extra water between meals, have a glass of milk with every meal. Fluid retention may make you feel sluggish and you’ll notice that your ankles will swell. This swelling will go down at night when your feet are up while you’re sleeping. This leads to frequent night time urination.