Definition

Amniocentesis is a test during pregnancy. It removes a small amount of the fluid that surrounds the baby for testing.

Amniocentesis Copyright © Nucleus Medical Media, Inc.

Reasons for Procedure

This procedure is done on those at high risk after 15 weeks of pregnancy. It tests cells in the fluid to look for signs of:

• Missing or extra chromosomes that may point to a birth defect and/or intellectual disability such as Down syndrome
• Birth defects of the brain, spine, or spinal cord
• Infection
• Inherited genetic diseases, such as: sickle cell disease, Cystic fibrosis, and Tay-Sachs disease
• Fetal anemia

This test may also be done to make sure the baby's lungs are growing as expected.

Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

• Bleeding, cramping, and fluid leaking from the vagina
• Infection
• Mixing of blood if the mother and baby have different blood types
• Need for repeat testing
• Harm to the fetus by the needle—rare
• Miscarriage—rare

Things that may raise the risk of problems are:

• Obesity in the mother
• Prior abdominal surgery

What to Expect

Call Your Doctor

Call the doctor if you are not getting better or you have:

• Signs of infection, such as fever and chills
• Nausea or vomiting
• Pain or cramping in the belly
• Blood or fluid leaking from the vagina
• Redness, swelling, increasing pain, excessive bleeding, or discharge from the amniocentesis site
• New or worsening symptoms

If you think you have an emergency, call for medical help right away.