Amniocentesis, or an amniotic fluid test (AFT) is an option offered to certain women, but you don't have to take it.
However, it is strongly recommended if you are over the age of 38 because of the increased risk of Down's Syndrome in older mothers.
AFT is also recommended if you have a history of Down's in the family or a history of certain hereditary illnesses. If your doctor recommends you go for screening, there will always be a medical reason for it.
You'll receive the results within three weeks. Amniocentesis can also determine the sex of your baby.