Tests and scans

Booking tests and scans is easy

The number of antenatal tests and scans can seem overwhelming, but don’t worry, we’re here to explain everything—and to help. We can arrange most of them for you in our rooms on your first visit.

What we test and scan for

A blood group and antibody screen

This screen checks your blood group (A, B, O or AB) and rhesus status (positive or negative). It also checks for antibodies (which may be important if you need a blood transfusion, and can affect the blood of the fetus).

A full blood count

This tests for anaemia, or a deficiency of red blood cells or of haemoglobin.

A hepatitis B and C serology

This checks to see if you have been exposed to either of these viruses.

An HIV serology

This checks to see if you have been exposed to HIV. Although it is uncommon in Australia, this is an important test as there are very effective treatments available to help prevent transmission of HIV to your baby.

A rubella serology

This checks to see if you are immune to rubella (German measles).

A syphilis serology

This checks to see if you have been exposed to syphilis, which can seriously affect the fetus. Again, this is rare, but effective treatments are available.

A urine microscopy and culture

This checks for urine infection. In pregnancy, bacteria may be present in the urine without the symptoms of an infection. It can cause kidney infections or increase the risk of preterm labour.

Scanning for Down Syndrome, Trisomy 18 and neural tube defects

In a small number of pregnancies, a baby can develop with serious problems, including Down Syndrome, Trisomy 18 and neural tube defects. You can choose to have testing in your pregnancy to see if your baby is at increased risk for one of these conditions.

Before you proceed with the testing, we will explain to you how these problems can affect you and your baby, what the test can tell you, and what the results might mean for you. It is very important to discuss all of this with your doctor and your partner so that you can make the right choices for you your baby.

Diabetes screening—Oral Glucose Challenge Test

Around 10%-15% of pregnant women develop gestational diabetes, which can have important implications for your health and the health of your developing baby.

Although there are some risk factors for developing diabetes, it is not possible to always predict who may be affected. For this reason, all pregnant women are offered the Oral Glucose Challenge Test at approximately 28 weeks.

This is a fasting test, which means no food, sugary drinks, tea, coffee, or juice; however, you should drink water as normal to stay hydrated.

The test involves:

• Collecting a fasting blood sample at the beginning of your test.
• Drinking a 75 g bottle of glucose within five minutes.
• Collecting a blood sample one hour after the glucose drink.
• Collecting a blood sample two hours after the glucose drink.

You can do the test on our rooms, or make an appointment and visit a collection centre. Wherever you do the test, you will need to stay there for an hour or two just in case you begin feeling unwell.

Ultrasounds

We have an ultrasound machine in our rooms and can check your baby at any stage during your clinic visits. You will also have a number of formal ultrasounds during your pregnancy.

Dating ultrasound

At your first visit, the dating ultrasound checks your baby’s heartbeat, confirms your due date and investigates whether you have a multiple pregnancy.

Nuchal translucency scan ultrasound

The nuchal translucency scan ultrasound is done between 11 weeks and 14 weeks into your pregnancy. We have a general look at the baby and measure the thickness of the layer at the back of the baby’s neck. It is this value that—combined with your blood test results—helps estimate the baby’s risk of Down Syndrome.

Morphology scan ultrasound

The morphology scan ultrasound is best done between 19 and 21 weeks of pregnancy. It is a detailed scan which checks the baby’s developing brain, spine, heart, kidneys and other organs, as well as the growth of the baby, and the location of the placenta in the uterus to ensure it is not too close to the cervix. Most babies appear completely normal, but occasionally an abnormality may be found. If this occurs, the finding and the implications for your baby will be fully discussed with you.

Growth scan ultrasound

A growth scan ultrasound may be done at any stage if we are concerned that the baby is too small or too large, or if you have a medical condition (such as high blood pressure or diabetes) that can affect baby’s growth.

Non-invasive Prenatal Testing (NIPT, or Harmony Testing)

Non-Invasive Prenatal Testing (NIPT) is a new type of prenatal test that examines DNA from your unborn baby that is circulating in your bloodstream. It is non-invasive as it only requires a blood-sample from you.

This test can be performed as early as 10 weeks into your pregnancy and offers very accurate results. NIPT can detect nearly all pregnancies affected by Down Syndrome (Trisomy 21), Edwards Syndrome (Trisomy 18) and Trisomy 13—offering considerable reassurance for most mothers.

Of course we will discuss all NIPT results with you so that you understand your options and what the results mean for you and your baby.

Chorionic villus sampling (CVS) and amniocentesis

Sometimes it is necessary to perform testing on the genetic material of the baby. Common reasons include:

• A high risk of Down Syndrome or other chromosomal problems in the fetus, based on screening tests, or the age of the mother.
• A known genetic disease in the parents or family, such as cystic fibrosis.
• An abnormal finding on an ultrasound that is suspected to be related to an abnormality in baby’s genetic material.

The only way we can currently access baby’s genetic material during pregnancy is by taking a sample of placenta or amniotic fluid from the uterus.

Taking a placental sample is called a chorionic villus sampling (CVS) and taking amniotic fluid is called an amniocentesis (or ‘amnio’). Both of these procedures involve introducing a needle through the woman’s abdominal wall into the uterus and gently removing a tiny sample.

Ultrasound is used throughout the whole procedure to guide the position of the needle. The procedure typically takes just a few minutes and while it is uncomfortable, most women find they cope much better than they expect.

The sample is then sent to a laboratory for testing. Usually the cells from the sample will need to be grown in a culture, which takes time. It can be possible to obtain a preliminary result in a few days, but the final result often takes up to two weeks.

CVS is done from 10 to about 14 weeks of pregnancy. The risk of miscarriage in women who have undergone this procedure is estimated at 1 in 100. While CVS has a slightly higher risk of disturbing the pregnancy than amniocentesis, its main advantage is that the result is available earlier in the pregnancy.

Amniocentesis can be done at any time from about 15-16 weeks of pregnancy. The risk of miscarriage is estimated at about 1 in 200.

These tests are typically done at Adelaide Women’s Imaging Tennyson Centre, or at the Women’s and Children’s Hospital.

Gene Access Carrier Screening

Genetic carrier screen gives patients information regarding their chances of having a child with a genetic condition like cystic fibrosis (CF), fragile X syndrome (FXS) or spinal muscular atrophy (SMA). Carrier screening is recommended by RANZCOG before conception or during the first trimester.

For more information on carrier screening follow this link.

 

Tests and scans can seem daunting but we will talk you through all of your options. Just call Adelaide Obstetrics & Fertility on 08 8272 7755.