Diagnostic tests

Chorionic villus sampling (CVS)

Chorionic villus sampling is generally conducted from week 13 of pregnancy onwards. A small sample of tissue is taken from the placenta to test. This is done in one of two ways:

• Through the abdomen. When the test is conducted this way, an ultrasound guided needle is inserted through the abdomen, into the uterus, and through to the placenta. A sample is then taken of the placenta for testing.

• Through the cervix. When the test is conducted through the cervix, a thin tube with forceps attached is guided through the cervix to the placenta. A sample is then taken of the placenta for testing.

There are some risks to the test. There is a risk of vaginal bleeding in 10 in every 100 women. There is also a risk of miscarriage in 1 in every 100 women. Similar risk of miscarriage for 2 methods. The baby is monitored via ultrasound for a short time afterwards. There is also a smaller risk of infection due to procedure, and this occurs in 1 in every 1000 women.

Amniocentesis

An Amniocentesis is generally conducted from week 16 of pregnancy onwards. A small amount of the fluid inside your uterus is taken to test. An ultrasound guided needle is inserted through abdomen, and into the uterus, where a sample is taken. In less than 7/100 cases, a second attempt may be needed due to there being too small a sample. Similar to the CVS, there is a risk involved with this test, and this risk of miscarriage occurs in 1 in every 200 procedures. To ensure the baby’s safety, the baby is monitored on an ultrasound for a short time afterwards to make sure there are no complications. There is also a risk of infection due to procedure, and this occurs in 1 in every 1000 women.

Things to watch out for after amniocentesis or CVS

• A high temperature (38 degrees or higher)

• Heavy vaginal bleeding

• Shivering or feeling like you have the chills

• Pain that is too much or ongoing

• Contractions

• Clear fluid from the vagina

If you do experience any of the above, it is important to contact the hospital where you had your termination, or your GP.

We would like to thank Dr Ken Law  [MBBS (Hons), FRANZCOG] for adding to, and reviewing this content for accuracy. Dr Law is an Obstetrician and Gynaecologist in Brisbane, Queensland.

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