Pregnancy

The Woman During Pregnancy: Possible Problems and Complications:
Prenatal Tests

Amniocentesis
Amniocentesis is a procedure in which a long, thin needle is inserted through the woman’s abdomen to sample the amniotic fluid in which the fetus swims. It is usually performed 16 -18 weeks into the pregnancy in order to detect serious abnormalities in the fetus.
The results are usually available only after 3-4 weeks (for some problems earlier results are possible). Since there is a small risk of miscarriage as a result of the procedure, the woman and her doctor must weigh this risk against the benefits of learning about a genetic disorder in the fetus well before it is born. If such a disorder is found, another decision has to be made: Should an abortion be considered this late in the pregnancy?