From 8 February 2010, there are two screening options available for antenatal screening for Down syndrome and other conditions.

Screening can provide some information about the chance of your baby having Down syndrome or another condition.  The new screening options will improve the quality and safety of screening services for pregnant women who choose to have screening.

First Trimester Combined Screening

First Trimester Combined Screening combines the results from a blood test and a nuchal translucency (NT) scan with other information, such as age and weight, to give one risk result.

The blood test is taken between nine weeks and 13 weeks 6 days of pregnancy. It measures the pregnancy-associated plasma protein-A (PAPP-A) and beta human chorionic gonadotrophin (ßhCG). The levels of these tend to be different if you are carrying a baby with Down syndrome or another condition.

The NT scan is an ultrasound scan that is done between 11 weeks and 13 weeks 6 days of pregnancy.  It measures the thickness of the fluid-filled space at the base of the baby’s neck. Babies with Down syndrome and some other conditions tend to have a larger NT measurement.

Obtaining an NT scan result can sometimes be difficult. If an NT scan result cannot be obtained, a first trimester combined screening result cannot be calculated. If this happens, you will be offered second trimester maternal serum screening.

The blood test is available free of charge. There may be a charge for the NT scan.  Please ask your maternity care provider for more information.

Your maternity care provider will have the results of your screening in about a week to 10 days. They will be able to tell you whether you have a low or increased chance of having a baby with Down syndrome or another condition. They will discuss what this might mean for you.

First Trimester Combined Screening Consumer Resource

OR

Second Trimester Maternal Serum Screening

Second Trimester Maternal Serum Screening combines the results from a blood test with other information, such as age and weight, to give a single risk result.  This improved test will be more accurate than the current MSS2 test because it will measure four chemicals in the blood instead of three, and more information is taken into account when calculating the result. 

The blood test is best taken between 14 and 18 weeks of pregnancy but can be taken up until 20 weeks. It measures beta human chorionic gonadotrophin (ßhCG), alpha fetoprotein (AFP), unconjugated oestriol (μE3) and inhibin A. The levels of these tend to be different if you are carrying a baby with Down syndrome or another condition.

Your maternity care provider will have the results of your screening in about a week to 10 days. They will be able to tell you whether you have a low or increased chance of having a baby with Down syndrome or another condition. They will discuss what this might mean for you.

Like all screening, screening for Down syndrome and other conditions is not diagnostic.  It provides an indication of risk.  A low risk result means there is very little chance that the baby has any of the conditions screened for.  An increased risk result means there is a higher chance that the baby has Down syndrome or another condition. Women with an increased risk result are offered diagnostic testing. 

Second Trimester Maternal Serum Screening Consumer Resource

Increased Chance Consumer Resource

More Information

More information about screening for Down syndrome and other conditions can be found in the Frequently Asked Questions, or by talking to your maternity care provider or GP. Information for health professionals is also available on this website.