Pre Pregnancy Genetic Carrier Screening

Written by

Rob Buist

Published on


I’d like to recommend that you consider genetic carrier testing before you fall pregnant or in early pregnancy. There are a small number of rare conditions that can be harmful to your baby but are not part of the usual pregnancy genetic testing. The main focus of our testing during pregnancy is Down Syndrome and a number of other genetic and structural problems (e.g. cleft lip or spina bifida).

Conditions like Cystic Fibrosis (a severe disorder that mainly affects the lungs), Fragile X Syndrome (a cause of intellectual disability) and Spinal Muscular Atrophy (a cause of muscle weakness) are not routinely tested for during your pregnancy.

The thing about these conditions is that you or your partner could be carriers for these conditions without being affected yourselves or even having a family history of them. However if you are both carriers (e.g. Cystic fibrosis) or the mother is a carrier (Fragile X) it is possible for the baby to be affected. If one or other of you is a carrier we can then offer you appropriate testing of your baby relatively early on in your pregnancy (or even before the pregnancy if you are going through IVF). Before you fall pregnant is by far the best time to do this testing.

As these tests are of your own genetic makeup, you only need to do them once in your life.

Obviously we can now recommend such testing because it is available although Medicare does not help out with the cost.

Please also remember there is a number of what we call autosomal recessive conditions (e.g. Tay Sachs Disease) that affect members of the Jewish community so it is very important that if you and your partner are Jewish at least one of you has undergone testing for these conditions prior to pregnancy.

Please remember:

  • I recommend that you have testing for your carrier status for a number of conditions before your pregnancy if possible
  • These conditions are rare but devastating if they affect your child
  • You can be a carrier for these conditions without any problems yourself and without a family history of them

If you and / or your partner are carriers your baby may be

  • Affected by the condition, or
  • Unaffected by the condition, or
  • Another carrier for the condition (and unaffected).

If we are aware of your carrier status we can offer relevant testing early on in your pregnancy although this is done via a “needle” test (a CVS or amnio) which carry a very small risk of causing a miscarriage

With the best will in the world there are conditions we cannot test for – Cerebral Palsy and Autism are good examples – but it is worthwhile testing for the things we can test for (if you know what I mean).

I can organise these tests for you – all it involves is a simple blood test at one of the Douglass Hanly Moir labs.

The bad news: These tests cost $400. I don’t think Medicare chips in at all.

– Rob