Scans, tests and screening – what to expect during your pregnancy

First-time mum? Having a baby after a few years’ break and need a refresher? Things can change quickly in the medical world and something that was standard in antenatal care five years ago, may be slightly different today.

Your healthcare provider, midwife or obstetrician will advise you when and where to book in for various scans, tests and screens during your pregnancy.

What is a pregnancy ultrasound?

An ultrasound uses sound waves to create images of a developing baby. A specialist sonographer puts a little gel on the pregnant belly and gently rolls a transducer (wand) across it and images appear on a screen. Scans show how many embryos are present, measure the size and growth of a baby, the size and health of the placenta and – the best part – the heartbeat.

They are considered safe for parent and child as they don’t use the ionising radiation as x-rays do.

Pregnancy ultrasounds are not generally covered by private health insurance, but you will be entitled to Medicare rebates. Similarly, 3D and 4D scans are not covered as they are elective. If you choose to have one of these, specialists recommend booking in for between 28 and 32 weeks.

Different providers have different options for scan photos, so ask ahead of your appointment if you need to pay for them, if there are 3D/4D options and if you can bring a USB or similar for scan footage.

The scans that you can expect to have during your pregnancy follow below. Most women have two or three, although you might be offered more scans if you’re carryings twin (or more), for example.

Pregnancy scans and antenatal tests

Dating scan

Mums-to-be may choose to have an early dating scan for reasons that include confirmation of pregnancy, checking for multiples, after bleeding or a previous pregnancy loss.

What to expect: In this scan, you might see a kidney-bean shaped embryo, and a heartbeat! Note, that if the scan is conducted too early, the heartbeat may not be visible.

When (approx): 8-9 weeks

Cost (approx): Up to 12 weeks $150 (Medicare rebate: 59.50); 12-16 weeks $170 (Medicare rebate $59.50).

First trimester ultrasound

As well as being used as a dating scan, the nuchal translucency scan combines with a PAPP-A blood and measures the risk of Down Syndrome and other chromosomal abnormalities. This is commonly the first scan, and can be used to establish an estimated due date.

What to expect: You’ll have the blood test between weeks nine and 13 gestation, before the scan. At the ultrasound, you’ll see a more distinct ‘baby’ shape. The sonographer measures the nuchal fold (fatty area) at the back of the foetus’s neck, and that measurement is combined with the results of the blood test to establish the risk. If the results show a high risk, you health providers will talk you through options for further tests (Amniocentesis or CVS – see below).

When (approx): 11-13 weeks

Cost (approx): $250 (single baby); $320 (twins)

Morphology scan (‘20-week’, ‘genetic’ or ‘anomaly’ scan)

If you only have one scan, this will be it!

What to expect: The sonographer measures and assess the development of the heart, brain, lungs, kidney, face, spine, bladder, arms and legs, and look out for anomalies or any markers for concern. The scan can also determine the position of the placenta.

Here, you can expect to see a wriggling baby with kicking arms and legs, a pumping heart, 10 fingers and 10 toes – and possibly a thumb being sucked!

When (approx): 19-22 weeks

Cost (approx): $290 (single); $400 (twins)

Antenatal tests and screens

As well as scans, there are a number of antenatal tests that you might encounter during your pregnancy. Several of these are routine, to track your health as well as that of the unborn baby, whereas others are more specific and will be recommended by health care providers, if needed.

These are some of the tests and screens you may come across during pregnancy.

Alpha-fetoprotein (AFP) test (14-26 weeks): AFP is a protein made by the baby’s liver that passes from the placenta in the mother’s blood. A simple blood test checks that the protein levels are normal.

Amniocentesis: This test is usually offered, after 15 weeks, if the nuchal fold test indicates chromosomal abnormalities, there is a family history of a genetic condition or to verify foetal infections. It can also be used to find out the baby’s gender. A hollow needle is inserted into the amniotic sac that surrounds the foetus, drawing back a small sample of amniotic fluid that is tested in a laboratory.

Chorionic villi sampling (CVS): Similar to amniocentesis, CVS can be a carried out between 11 and 14 weeks where a thin needle is inserted into the placenta to extract a small sample of tissue for testing.

Full blood test (early pregnancy, and approx. 28 weeks): In early pregnancy, you’ll be tested to find out your blood group, rubella status, iron levels and potential hepatitis B, hepatitis C, HIV or Syphilis. If any issues are flagged here, you’ll receive specific advice on specific needs and will be tested again at about 28 weeks.

Glucose tolerance test (28 weeks): To monitor for gestational diabetes. You’ll be asked to fast for 8-12 hours before this test, so try to get an early appointment or arrive early at the clinic if it’s a walk-in. They’ll conduct a fasting blood test, then you’ll drink a sugary drink and wait for one to two hours before having a second test. Take a good book!

Group Strep B test (GSB): GSB bacteria exists in the vagina, bowel and anus, and while it’s harmless to mum-to-be, if transferred to the infant as they’re born it can cause infection and sickness. A simple screening swab can be done at about 36 weeks and if the test is positive, your midwife or doctor will explain treatment and preventative options ahead of your labour and birth.

Urine tests: You might be offered urine tests at different times in your pregnancy, to rule out infections that have no symptoms, and to check on the protein levels as these may need to be monitored.