Amniotic fluid is withdrawn when doctors suspect that your baby has a higher risk for a genetic condition.


  • From 15 weeks of gestation
  • If your baby is suspected to have an increased risk of a genetic condition.
  • To obtain other data on the health of the fetus, such as infectious diseases and the rhesus problem.


Duration: 30 minutes

Amniocentesis tests are performed at the ultrasound centre.

The procedure begins with ultrasound imaging.

  • Then, guided by an ultrasound image, a long, thin needle is inserted through the abdominal wall before puncturing the amniotic fluid sac.
  • At this point, 15-20 ml of amniotic fluid is withdrawn.
  • This small sample is subsequently tested for abnormalities.


  • The entire chromosomal analysis (karyotype) takes approximately 1 week.
  • FISH, a rapid test for Down syndrome, provides definitive results within 2 to 4 days.

Risk factors

After amniocentesis, a woman’s additional risk of a miscarriage is estimated at 0.3%. This risk decreases as the pregnancy progresses.


It is best to take it easy for a couple of days after having this test.

About amniocentesis

Amniotic fluid contains cells that originate from the skin and mucous membranes of the fetus. The chromosomal pattern of the fetus can be determined by examining these cells in a genetic testing laboratory.

Last edit: 16 June 2021