Tests during pregnancy: what to expect

Updated December 2022 | 5 min read 
Expert contributors Terri Barrett, former president of the Australian College of Midwives; Dr Charlotte Elder, obstetrician and gynaecologist 
Words by Sophia Auld  

Getting tests during pregnancy is important for both your and your baby’s health. Here’s what to expect with each medical test, when you’ll be tested and how to prepare. 

There are a number of tests during pregnancy that you’ll be offered as a way to keep an eye on your health, and that of your baby. It may seem like there are a lot of tests to keep track of, but your midwife, GP or obstetrician will talk you through what’s needed and when.  

What to consider with your tests during pregnancy 

While tests aren’t mandatory, “the results of these investigations provide the woman, her family and care provider with valuable information that can be important to the woman’s choices around her pregnancy and labour care,” says Terri Barrett, former president of the Australian College of Midwives. 

Test results may indicate the need for further investigations or review by another health professional. “In some instances, identification of risk may mean a change in the initial plans for the pregnancy or birth including transferring the woman for higher-level care,” she says. 

Terri adds you need to be aware of the potential risks and benefits of any investigation or treatment before consenting. 

Think about what you’ll learn from each test, and how you may use that information, says obstetrician and gynaecologist, Dr Charlotte Elder, especially when it comes to genetic screening. 

"Having an idea about where you stand and what your values are is a really important part of deciding around [these] tests. Women and their partners [should] discuss these issues before they decide whether to have [the tests].” 

Tests before getting pregnant

Before you even fall pregnant, your doctor may carry out a genetic assessment to determine what tests you should have. You may also like to consider testing for common genetic conditions like cystic fibrosis, spinal muscular atrophy and fragile X syndrome, which can cause significant health problems.

Tests in your first trimester (week one to 12)

Pregnancy tests

A missed period is one of the most common signs that you may be pregnant, but it isn’t always accurate. Taking a pregnancy test is one of the most common tests to help you confirm whether you’re pregnant or not. The various types of pregnancy tests include:

• home test kits: these tests are 97 to 99% accurate (when used correctly) and are available at your local supermarket or chemist
• urine test at your GP: test the levels of the pregnancy hormone called human chronic gonadotropin (hCG)
• blood test: can be accurate within one week of conception and like the urine test, will read the levels of hCG.

Blood tests

Once you’ve confirmed you’re pregnant, you’ll have blood tests to screen for infections including German measles (rubella) and chicken pox, vitamin deficiency and medical conditions. Testing for hepatitis B and C, HIV and syphilis is also recommended, because although these conditions are relatively rare, the right management can reduce the chance of the baby acquiring an infection.

Your iron levels will also be tested throughout your pregnancy, as well as other vitamin levels like D and B12. A full blood examination looks at your blood group, rhesus status, platelet levels, and for disorders such as anaemia and thalassemia. You’ll have these blood tests in your second and third trimesters too.

Ultrasounds

You’ll usually have an ultrasound at six to 10 weeks to confirm the baby’s due date and to check for twins or triplets. You’ll then have another scan at 12 to 13 weeks to check on the baby’s growth and development.

Genetic tests

Testing for genetic conditions caused by chromosomal abnormalities is another consideration. Combined serum screening checks hormones in your blood at around 10 weeks, and an ultrasound measures the thickness of baby’s neck at about 12 weeks. These measurements are combined with your height, weight and age, to calculate the risk of your pregnancy being affected.

An optional screen for genetic abnormalities can be done anytime from nine to 35 weeks. Non-invasive prenatal screening (NIPS) involves a blood test looking at DNA from the placenta that’s released into your blood. It checks the sex chromosomes, and for changes that could cause chromosomal conditions. An example of this is the Harmony test.

If combined serum screening and NIPS testing show there’s a high likelihood of a specific birth defect, you can choose to have further tests, like chorionic villus sampling at 10 to 19 weeks or amniocentesis between 16 to 20 weeks. As these tests carry a risk of miscarriage they’ll usually only be done if your baby is at higher risk of having a birth defect.

Tests in your second trimester (week 13 to 26)

Tracking your pregnancy

During your second trimester, your obstetrician or midwife will keep track of your blood pressure and weight, and your baby’s growth and progress.

You’ll also have another ultrasound at around 20 weeks to check on the baby’s growth and the location of the placenta. This ultrasound can also determine the gender of the baby (if you want to know).

Tests in your third trimester (week 27 to end of pregnancy)

Between 24 and 28 weeks, you’ll be screened for gestational diabetes. This is a fasting blood test, with two more blood samples taken at intervals after a glucose drink, to test how your body responds to sugar.

At 36 weeks, a vaginal swab to check for group B streptococcus – a bacterial infection that may have serious consequences – may also be performed.

Mental health screening

Another element of pregnancy testing is screening for psychosocial issues that might affect your pregnancy, like depression, anxiety and family or domestic violence.

Your doctor will screen you for depression using a questionnaire that asks set questions about how you’re feeling. This is important because 10 to 15% of women will be diagnosed with depression during pregnancy and in the postnatal period.

Signs of depression during pregnancy and the postnatal period can include:

• reduced interest in things you’d normally enjoy
• increased crying (sometimes for no apparent reason)
• consistently feeling depressed or miserable
• feeling helpless, hopeless and worthless
• unexpected changes in sleep or appetite
• feeling irritable, angry or anxious a lot of the time
• having thoughts of harming yourself, your baby or other children.

It’s important to remember that antenatal and postnatal depression and anxiety is treatable. According to Healthdirect Australia's Pregnancy and Birth Baby, there are two types of psychological therapies that have been proven to be effective in managing depression. These are:

• cognitive behavioural therapy: to help you identify negative thoughts and learn how to challenge them by thinking in a different way
• interpersonal therapy: to help you resolve past losses, changes or conflicts that may be contributing to your depression.

If you need to talk to someone, contact Beyond Blue on 1300 224 636 or the PANDA National Perinatal Mental Health Helpline on 1300 726 306 from 9am to 7.30pm AEST/AEDT.

If you prefer a self-help approach to online mental health support, This Way Up^* is a not-for-profit hub offering a suite of interactive programs to help manage symptoms of a range of conditions like anxiety, depression and social anxiety. There are also coping and resilience resources, multilingual resources and self-led programs for peri and postnatal mental health.

The programs are available free of charge when prescribed by a clinician. Your provider will register with This Way Up and refer you to an appropriate online program under their supervision. Alternatively, you can access the programs without a supervising clinician for $59 per program. 

How to prepare for your tests during pregnancy

• If your test involves fasting, bring some food in your bag for afterwards.
• Ultrasounds often involve having an almost full bladder. Be sure to follow whatever instructions you’re given.
• If you’re concerned about any of your tests or nervous about needles, let your healthcare providers know.
• Bringing a support person to appointments can help with remembering information.

Support when you need it most

If you’re struggling with your pregnancy and need someone to talk to, we’ve expanded our mental health offering to include a free HCF HealthyMinds Check-in for eligible members^{^}. This gives you faster, easier access to qualified mental health professionals and digital support services to help you take control of your mental wellbeing.

So, whether you’re looking for support for yourself or your loved ones, our unique range of mental health and wellbeing programs can help you understand and improve mental health challenges such as stress, anxiety and depression.