Amniocentesis: what to know

During the procedure, ultrasound helps guide a fine needle through the abdomen into the amniotic sac, avoiding the fetus and placenta where possible. The fluid contains cells and other material that a laboratory can analyse for the conditions included in the test. Results may answer a specific question; they do not assess every possible health or developmental concern. Amniocentesis is different from screening tests, which estimate the chance of a condition.

Your maternity team will explain the reason for testing, possible findings, alternatives and how results will be reported. Tell them about medicines, bleeding problems, allergies and your blood group if known. Arrange time to rest afterwards and follow the team’s instructions about activity. Depending on the question, alternatives may include chorionic villus sampling or NIPT, though these tests answer different questions and are performed at different stages.

After amniocentesis, contact your maternity team promptly for vaginal bleeding, fluid leaking from the vagina, fever, worsening abdominal pain, contractions, dizziness or feeling unwell. Ask where to call before leaving the appointment. Emotional support may also be useful while waiting for or discussing results.

What condition is this test checking for, and what will the result tell me? When and how will I receive results? What are the alternatives for my stage of pregnancy? What symptoms after the procedure should prompt an urgent call?