Antenatal tests

Ultrasounds – A dating ultrasound will be performed in the rooms at your first visit to confirm the dates of the pregnancy so please come to your first appointment with a reasonably full bladder. After this, there are generally two further ultrasound scans performed during the pregnancy. The first is often as part of the Downs Syndrome screening test at 11 to 14 weeks. The second is the morphology scan (detailed head to toe examination of the baby) that is performed at 19-20 weeks. Ultrasound scans in later pregnancy are sometimes required in certain situations such as to monitor the growth of the baby (too big or too small), if you have a medical condition (such as diabetes or high blood pressure) or a follow up scan to check placental position.

Blood tests – Routine blood tests are performed at some point in the first trimester. This is to give an idea of your blood count, blood group etc, plus to look at whether you have any infections that can be managed eg. Hepatitis, syphilis.  More blood tests are then routine at 28 weeks – this is a diagnostic diabetes test, repeat blood count and antibody screen. Sometimes iron and vitamin D will be added in. This is generally he only routine blood tests that are done although follow up tests may need to be performed. All blood tests are however tailored to the individual.

Swabs – A low vaginal swab will be performed at 36 weeks if you are planning on a vaginal delivery. This is to check for GBS (Group B Streptococcus), a common bacteria that is present in the female genital tract in up to 15 to 20 per cent of women. Although generally not having an affect on you, the bacteria may have an affect on the baby during a vaginal delivery. To minimise the chances of this happening, antibiotics will be given to you during labour if you swab is positive. An information sheet will be given to you by the midwife at the time the swab is performed.

Down Syndrome Testing – The most important thing to note about these tests is that they are purely optional,  for most people a decision is based around their thoughts/ believes around termination of a pregnancy. It is also important that no matter where you start in the screening process a termination for Trisomy 21 (Down Syndrome) cannot be carried out without having the result of a diagnostic test, either a CVS or amniocentesis.
There are 2 options. The first is the First Trimester Maternal Serum Screening test – this is a blood test (that measures placental hormones) in conjunction with the 12 week ultrasound. Given that the 12 week scan in now considered routine in SA there is no additional cost for this test. This provides you with a ‘risk factor’ assessment  that helps you decide if you need further testing and if so, what sort.
The other option is known as NIPT (non- invasive perinatal testing) – of which the most common one in use is called ‘Harmony’. This is an assessment  of the amount of free dNA from the baby that is present in the mums blood. It has a high level of accuracy, is performed as well as the 12 week ultrasound and costs around $450. This is not reclaimable from either Medicare or your private health fund. The Clinpath website is excellent and worth a look at if you’re considering this option, you can visit it at http://www.sonicgenetics.com.au/nipt/
Please be aware that these tests will be discussed in much more detail at your first visit, this is written to provide you with a brief overview.