Prenatal diagnosis of Down syndrome

If prenatal screening identifies an increased likelihood of the fetus having Down syndrome, or other fetal condition, then the woman is offered diagnostic tests during pregnancy:

• chorionic villus sampling (CVS) at 11 to 14 weeks
• amniocentesis after 15 weeks.

These tests accurately identify chromosomal differences in the fetus, but do not identify other causes of developmental difference and disability such as intrauterine infection, hypoxia, toxins or trauma. CVS and amniocentesis are invasive and have a very low risk of miscarriage.

For advice on preconception testing, see the Royal Australian College of General Practitioners (RACGP) guidelines on Genomics in general practice. Pre-implantation genetic diagnosis is an option for couples undergoing in-vitro fertilisation who are at increased risk of passing on certain genetic conditions.

For advice on discussing a developmental disability diagnosis with parents, see here. See also Support for carers and family of people with developmental disability.