they are certainly not recommended.
they are used to do further testing. i had one done at 22 weeks with my 2nd to further test for genetic disorders.
what they do is try to numb and sterilize the insertion area with iodine, insert a long but very thin needle through your stomach in the belly button area, until it pokes through the uterus. then the needle is removed and a catheter is put in it's place, so the needle doesn't stay the whole time. all the while, another technician monitors everything that's being done via ultrasound, so the OB can see what she's doing. they will withdraw some amniotic fluid and send it off to be tested. they can tell you without a doubt what the sex of your baby is this way. they can do dna testing this way.
i felt a slight pinch when she popped thru the uterus, nothing major, and slight burning in the insertion area most of the day. the risk of miscarriage is less than 1%.
at 6:39 PM on Oct. 21, 2010