How long does it take to get amniocentesis results?

The typical time required to get the test results from an amniocentesis is approximately two to three weeks. If a woman has not received amniocentesis results after three weeks, she should contact her physician, according to WebMD.

An amniocentesis is a test performed on a mother and her unborn baby to evaluate the presence of certain birth defects, such as Down syndrome. This test does carry some risk to the mother and unborn baby, and is usually only performed if there is a known risk of possible birth defects. Possible risks include: findings from an abnormal ultrasound, a maternal age of 35 and over and a family history of birth defects.