This update was undertaken as part of the regular updates to Green-top Guidelines as outlined in our document Developing a Green-top Guideline: Guidance for developers (PDF) and prior to the emergence of the new COVID-19 coronavirus.
Please note that the information provided in this update will be considered for update 3 years after publication, with an intermediate assessment of the need to update 2 years after publication.
Version and edition
This is an update of the 2010 version of this guideline in the new format. It is the fifth edition, which was previously published in October 1996, February 2000, January 2005 and June 2010.
Pregnant women are offered amniocentesis or chorionic villus sampling (CVS) for prenatal diagnosis for a variety of reasons including a higher chance aneuploidy screening result, fetal structural anomaly, or a known risk of inherited genetic disease.
CVS is usually performed between 11+0 and 13+6 weeks of gestation. If required, CVS can be performed between 14+0 and 14+6 weeks’ gestation. Individualised counselling of the merits of CVS versus amniocentesis should be provided for women considering CVS during this time period. Amniocentesis, performed to obtain amniotic fluid for analysis, is usually offered from 15+0 weeks.
Amniocentesis, chorionic villus sampling, prenatal testing
Declarations of interest
Dr K Navaratnam: None declared.
Professor Z Alfirevic: None declared.
Demonstration of the recommended technique for amniocentesis