Screening for Downs Syndrome and other chromasomal (genetic) abnormalities is routinely offered. Women are advised to undergo some risk screening prior to any diagnostic screening as there are risks associated with invasive screening methods.

 

Risk screening tests  - there are two screening tests, one in the first trimester and one in the second trimester. For more information about testing go to the National Screening Unit website www.nsu.govt.nz

 

Diagnostic tests - these should only be recommended to women with a high risk of chromasomal (genetic) abnormality.

 

Chorionic villus sampling (CVS) involves taking a small sample of the chorionic villi, which are the tiny units that make up the placenta. Using ultrasound as a guide, the sample is obtained by inserting a cannula up through the vagina and cervix (transcervical) or by inserting a needle in through your stomach (transabdominal).

 

Amniocentesis  involves taking a small sample of amniotic fluid from around the foetus with a needle introduced through the abdomen.

 

Both these tests carry a risk of miscarriage.