one of The cause of increased fluid level itself is congenital abnormality in baby.The over stretching of uterus
may lead to rupture of membranes
BUT DONT WORRY.your dr. must have evaluated the fact by sonography
&adviced you accordingly.
NOW,it's your duty to follow the instructions &be careful .don't be tense-for the fluid level does come down with the treatment& women do deliver normal babies after such a condition like yours. so-----cheer up!be +ve &be careful.