Reproductive carrier screening: Planning for parenthood

Genetic testing before and during pregnancy may provide information to assess the chance of passing on certain conditions to your children. This may give you more reproductive options and a chance to plan and prepare.

While most people don't consider genetic screening until they're pregnant, pre-pregnancy testing is available and becoming more popular.

Reproductive genetic carrier screening is a test that checks if you have changes in specific genes that could be passed on to your children and potentially cause genetic conditions.

A 'carrier' usually does not have the genetic condition themselves, and may not know they carry this gene variant.

"It's not unusual to be a carrier for a genetic condition. Most of us are," explains Associate Professor Melody Menezes, Clinical Director at Victorian Clinical Genetics Services (VCGS).

Carrier screening is recommended before you conceive, but it can also be done in early pregnancy.

"It's important to understand that reproductive carrier screening is a test of the parents and their genes to see what they might pass on to a child. This is different to prenatal screening during pregnancy which looks to see if the developing baby might have a chromosome condition such as Down syndrome or Edwards syndrome."

There are 2 screening options: 3 condition screening and expanded screening for over 1,000 conditions.

3 condition screening has recently been made available under Medicare, making it widely accessible for those planning a pregnancy. This screening looks for 3 of the most common inherited genetic conditions in the Australian population:

• cystic fibrosis
• spinal muscular atrophy
• fragile X syndrome.

"That test is usually offered to the female member of the couple first. If that individual carries a genetic change in one of the genes associated with those conditions, the other partner is then also tested."

"This provides more information about their chance of having children with one of these conditions," says Melody.

Any kind of genetic testing before or during pregnancy may help give families and individuals information and options, says Melody.

The biggest benefit to reproductive carrier screening pre-pregnancy is it can give you the most reproductive choices and time to plan and prepare.

If you are at increased chance of having a child with a significant genetic condition, there are many reproductive options available.

You could choose IVF and test embryos for the condition to avoid passing it on. There are additional Medicare rebates for this.

"Alternatively, you could choose to conceive naturally and test a pregnancy for the specific condition," says Melody.

All genetic testing in Australia is optional, but if you are pregnant and want to do carrier screening it's safe, says Melody. Reproductive carrier screening is tested via blood or saliva, so is safe to do during pregnancy.

"There is no risk of miscarriage from this type of genetic screening. It doesn't carry any more risk than a standard blood test."

Carrier screening is a personal choice and not compulsory in Australia.

A factor that some people consider might be a family history of a genetic condition. However, this is not a reliable indicator, says Melody.

"Research shows that we would miss most affected pregnancies and most carriers if we relied on family history alone. Ethnicity and family history are unreliable indicators, which is why it is so important that the government decided to fund 3 condition carrier screening for these commonly inherited genetic conditions."

Talk to your GP or healthcare provider about genetic testing before or during pregnancy if you have questions or simply want to know more about your options.