Re: not enough fluid
Low amniotic fluid is not a good thing for your baby. It lessens the cushioning effect of the sac of waters, and if the fluid gets very low, there is a risk that the cord could be compressed especially upon labor.
After a woman passes her due date, it is common for obstetricians to order the fluid measured in an ultrasound. The sonographer will measure the fluid at four even points around the baby (the noon mark, the 3 o'clock mark, 6 o'clock, & 9 o'clock) and add up the measurements. 10cm is healthy. 5cmm is worrisome.
I had this test done at my 1 week past-due (41 week) appointment with my first baby. My measurement was 1.5cm and they asked me to stay in the hospital so they could induce labor, to prevent my baby from experiencing distress especially since the fluid would get even lower over time. It turned out his heart rate was fine through the whole labor, which was fortunate. I have an acquaintance whose measurement was even lower than that and they had to induce her too.
When the pregnancy is overdue, the low fluid is not so much caused by you not drinking enough fluids as it is by your placenta being old and absorbing the fluid or not tranmitting enough fluid to the sac (not sure which). Prior to being overdue, though, it's extremely important that you get enough fluids by drinking LOTS of water. Your pee should be the faintest yellow, almost clear -- any yellower than that and you need to be drinking more. You should be drinking as much water as you can to get to this point -- I found that 8 glasses a day was not enough. Whole milk is good too since it has the calcium and fat your baby needs for bone and brain development. Stay away from too much juice as it has sugar that you don't need and that can be dangerous if you have gestational diabetes.