Amniocentesis – Prenatal Diagnosis of Genetic Disorders

Framed Embroidery Chromosome Art (Photo credit: Hey Paul Studios)

‘Amniocentesis’ is a medical test for prenatal diagnosis of genetic disorders in the fetuses. A small quantity of amniotic fluid is withdrawn in an aseptic manner and cultured in the genetic laboratory to investigate the chromosomal abnormalities. The test is usually done between 15- 20 weeks of pregnancy.

How this Aminocentesis procedure is done?

This procedure is done in a surgical theater using aseptic precautions and safety methods under local anesthesia. After injecting a local anesthetic a needle is passed under the guidance of an ultrasound into the amniotic sac. The selection of the place is carefully monitored to avoid any injury to the fetus. It is delicate procedure should be done by an expert. A small quantity of amniotic fluid about 20 ml is withdrawn using a syringe and sent to the genetic laboratory for culture. In the lab the cells are separated and cultured in a special culture medium. After culturing, the cells are stained and the chromosomes are studied for abnormalities.

Indications for the test:

• Down’s Syndrome: A chromosomal disorder wherein an extra chromosome is inherited (T21) making 47 chromosomes instead of 46. Due to this the physical characters are altered and development delayed.
• To study any other chromosomal abnormalities.
• To study neural tube defects.
• Any infections.
• Rh in compatibility.
• In women more than 35 years age.
• Birth of any abnormal children previously.
• Doubts in ultrasound or blood test indicating to do this test. A latest emerging study revealed that amniotic cells can also be used as stem cells .However due to risk for the fetus the use of the amniotic cells is limited.

Possible Complications:

• Infection
• Pre term delivery
• Miscarriages
• Fetal injury