This is a simple procedure to obtain a small amount of amniotic fluid (about 20mL) by inserting a special needle through the mother’s tummy and into the uterus. The needle will always be under ultrasound guidance so that it does not harm the fetus. The reasons for performing an amniocentesis test are essentially the same as that for doing a chorionic villus sampling. The amnio test is done after 15 weeks. The safety and complications of amnio test are also similar to CVS in experienced hands. Choosing between the two tests is a matter of preference by the physician: CVS has the advantage of early testing while amnio has the advantage of being widely available due to