Amniocentesis may be done when soon when there exists plenty amniotic fluid surrounding the foetus that a sample may be flushed safely. Early amnio may be performed when early when Long dozen weeks gestation. Standard amnio is ordinarily performed between 15 & 20 weeks gestation. Resolutions choose astir fortnight. Typically, genetic counseling is done before amnio, or even more types of genetic testing, is offered.

Risks
Amniocentesis is slightly less risky to the infant than chorionic villus sampling although villus sampling can be done earliest. Amniocentesis neutralize the 2nd trimester is typically said to have a chance of foetal demise between astir Ace inside 400 & One around 200.

Procedure
Amniotic fluid is typically found applying an extended syringe, guided by ultrasound. A syringe is unremarkably inserted through the mother's belly, & as well at a prevent of the vagina, and amniotic fluid aspirate.

Tests
In the amniotic fluid there are traces of the tots's skin & more cells that own sloughed off a young child piece it's growing. Chromosomes and/or DNA from these cells in the fluid are so analysed, commonly to rule out genetic abnormalities which could are causal agents for birth defects. This may be cytogenetics or simply wanting to find abnormal factor. (a side burden of cytogenetical analysis is determining the sex of the foetus, although that is sir thomas more normally found across ultrasound.)

Too when genetic testing, levels of other substances, (like alpha-fetoprotein) can be measured to detect more ill health. Amniocentesis just can't detect completely conceivable transmitted problems or even congenital abnormality.