Is it safe to get an amniocentesis?

Yes: Amniocentesis is largely safe, though in very rare cases the membranes (bag of waters) can be ruptured by the procedure. We used to quote 1:300 risk, but with modern amnio needles and ultrasound guidance the risk is now much lower. Ruptures that occur from amnio are typically small and often reseal on their own.

Yes: There are 2 main reasons amniocentesis is done. Genetic amnio is done at 16-18 weeks, testing for down's or other chromosome problems. There is a 1 in 3-400 chance that you could lose a pregnancy because of it. The other reason is to test for the baby's lung ability to breathe well. This is generally done between 35-38+ weeks. The only risks are that you might deliver.