Amniocentesis performed at the 16-18 week of gestation uses amniotic fluid to test for chromosomal abnormalities. It can also be used to find biochemical abnormalities at the genetic level, detecting up to 180 genetic disorders. CVS is performed 10-12 weeks into gestation and uses chorion tissue for chromosomal analysis in biochemical and DNA studies. This test is not widely used because of correlation to producing newborns with limb abnormalities. PUBS can be performed after week 18 and is used only as a confirmation test based on results from previous tests.
Fetal biopsy involves taking fetal tissue for DNA testing.
General international opinion about programs of genetic testing and screening is represented by the recommendations of the UK Nuffield Council on Bioethics. These include the requirement for informed consent and that all written information should be s supplemented with counseling, individuals and parents of unborn or young children, should be fully informed of the results of genetic screening and their implications for the family, genetic screening of employees should only be contemplated when either there is a clear connection between the working environment and the development of the condition screened for, or where the condition seriously endangers the health of the employee or third parties. The Committee of Ministers of the Council of Europe thinks that the public generally recognizes the benefits and the potential usefulness of genetic testing and screening for individuals, for families, and for the population as a whole, but it says that there is an accompanying anxiety that genetic testing and screening arouses. The Danish Council of Ethics views genetic information as different from other private information since it reveals knowledge not only about an individual, but also the individual's relatives, and because analyses will provide comprehensive information about both individuals and population groups. The Council says that screening provides information useful either to the individual or to public health officials, but this information is not concerned with treatment.