Amniocentesis: Purpose, procedure, risks, diagnostic accuracy of this invasive prenatal test

Amniocentesis is a medical procedure used to diagnose certain genetic and chromosomal abnormalities in a developing fetus and it involves the extraction of a small amount of amniotic fluid from the uterus, which surrounds the fetus. In other words, Amniocentesis is an invasive prenatal test in which your doctor takes a sample of the amniotic fluid where the sample of 15-20 ml is removed through a fine needle inserted into the uterus through your abdomen, under ultrasound guidance and a lab tests the sample, checking your baby’s chromosomes.

Purpose:

Talking about why Amniocentesis is performed, Dr Bhavna S Mehta, Senior Consultant OBGYN at Cloudnine Group of Hospitals in Chennai, shared that the Amniocentesis is performed to look for certain types of birth defects, such as Down syndrome, a chromosomal abnormality and the prenatal test is generally offered to women who have a significant risk for genetic diseases, including those who:

• Have an abnormal ultrasound or abnormal lab screens
• Have a family history of certain birth defects
• Have previously had a child or pregnancy with a birth defect
• Had an abnormal genetic test result in the current pregnancy.

According to her, it can be used to detect the following conditions if the parents have a significant genetic risk:

• Down syndrome
• Sickle cell disease
• Cystic fibrosis
• Muscular dystrophy
• Taysach s disease
• Thalassemia (Major)

When Is Amniocentesis Performed?

Dr Bhavna S Mehta answered, “The procedure is usually scheduled once between the 15th and 18th weeks of pregnancy.”

Diagnostic accuracy:

Highlighting how accurate Amniocentesis is, Dr Bhavna S Mehta said, “The accuracy of amniocentesis is about 99.4%. Amniocentesis may occasionally be unsuccessful due to technical problems, such as being unable to collect an adequate amount of amniotic fluid or failure of the collected cells to grow when cultured.”

Risks and complications:

Cautioning against the risks of Amniocentesis, Dr Bhavna S Mehta revealed, “There is a small risk that an amniocentesis could cause a miscarriage (less than 1%, or approximately 1 in 1,000 to 1 in 43,000). Injury to the baby or mother, infection, and preterm labor are other potential complications that are rare. You may feel minor menstrual-like cramping or discomfort during the amniocentesis or for a few hours after the procedure.”

Can I Resume Normal Activities After Amniocentesis?

“It is best to go home and relax for the remainder of the day. You should not exercise or perform any strenuous activity, lift anything over 20 pounds (including children), or have sex. The day after the procedure, you may resume all of your normal activities,” the health expert suggested.

When Should I Call My Doctor After Amniocentesis?

“Call your doctor if you develop a fever or have bleeding, vaginal discharge, or abdominal pain that is more severe than cramps,” Dr Bhavna S Mehta advised.

When Will I Receive the Results of the Amniocentesis?

Dr Bhavna S Mehta concluded, “The results of the amniocentesis are generally available within 2 or 3 weeks.”