Amniocentesis Test - Prenatal Genetic Testing

Amniocentesis is a prenatal test in which a small amount of amniotic fluid is removed from the sac surrounding the fetus for testing. The sample of amniotic fluid (less than one ounce) is removed through a fine needle inserted into the uterus through the abdomen, under ultrasound guidance.

Reasons to perform the procedure:

• Following a positive prenatal screening test like Dual, Quadruple Marker or NIPT (Non-Invasive prenatal testing).
• History of having a previous baby with a chromosomal condition like Down syndrome
• Family history/ parents affected with a specific genetic condition
• High maternal age: >35 yrs
• To evaluate the baby for an infection
• Therapeutic, in case of polyhydramnios, to reduce the volume of amniotic fluid.

Optimal time for the procedure:

• 16-18 weeks is the preferred time.

How to prepare:

• Disclose and discuss all medications before going for the procedure. Some medications might have to be discontinued before the procedure.
• Consider asking someone to accompany you to the appointment for emotional support and to drive you back.
• You will need to sign a consent form before the procedure.

What to expect after the procedure:

• Transient uterine cramping, spotting and vaginal loss of a few drops of amniotic fluid can occur immediately after the procedure.
• However, seek medical advice if you have persistent fluid leaking from the vagina, heavy vaginal bleeding, severe abdominal pain or fever.

Possible complications:

• Miscarriage (1 in 300 to 1 in 500). It usually occurs within the first 5 days of the procedure
• Risk is higher if
  • The procedure is done before 15 weeks of pregnancy
  • BMI>40kg/m2
  • Previous episode of vaginal bleeding during current pregnancy
  • History of previous spontaneous abortions
• Leaking amniotic fluid: Rare
• Infection: Rare
• Infection transmission from mother to baby (If the mother has Hepatitis C or Toxoplasmosis)
• Needle injury: Rare
• cramps
• a small amount of vaginal bleeding
• amniotic fluid that leaks out of the body (this is rare)
• uterine infection (also rare)

When can you expect the results:

• 2-3 weeks for karyotyping
• 3-5 days for QF-PCR

What can an amniocentesis test detect?

• Genetic disorders
• Birth differences 
• Your baby’s lung development
• Other health concerns