Although ultrasound scans are generally considered safe, there are differing views about whether or not pregnant women should routinely accept them. Most doctors support a routine scan to date a pregnancy at eight to 12 weeks and another at 18-22 weeks to check the baby’s organs and limbs.

Ultrasound scans are able to:

• confirm if the foetus is alive
• assess and confirm the due date
• establish whether the mother is carrying more than one child
• determine the sex of the baby
• identify abnormalities
• assess the health of the foetus following a threatened miscarriage
• determine the size and growth rate of the foetus
• measure the amount of amniotic fluid present
• identify placenta previa LINK
• confirm the positioning of the foetus
• assess the ongoing functioning of the placenta in an overdue pregnancy
• A scan can detect abnormalities like spina bifida, heart defect or kidney malfunction. Sometimes, however, scans do not detect an abnormality even when it is present.

An ultrasound takes about 10 minutes to perform and the results are instantaneous. Taking your partner is a good way to include him in the pregnancy and it is also a good idea to have support should your scan show any abnormality.

A radiographer, an ultrasonographer, an obstetrician or a midwife may carry out the scan.

A scanner probe is placed on your skin and very high frequency sound waves audible to the human ear are passed into your body. As the sound waves pass over objects in fluid, they produce a pattern of echoes, these are converted into electrical signals that are processed and displayed on a screen as a two-dimensional image.

Usually only an abdominal ultrasound is required, but a vaginal ultrasound, in which a slim probe is inserted into your vagina, maybe used if necessary.

You will be asked to have a full bladder for the procedure as it creates a more defined image of the womb and cervix. Gel is rubbed over your stomach to lubricate the surface. The scan lasts about 15 minutes and is painless.

Questions You May Wish To Ask

• What does the scan reveal about my baby?
• Does the scan confirm my expected delivery date?
• Can I have a photograph/video of my baby’s scan?
• What will you be looking for in future scans?
• Can you tell the sex of my baby?

Doppler Test

This scan has been used for 10 years and is considered safe but is not used in early pregnancy. It is carried out to indicate the blood flow in the baby or in the placenta. It is used to check babies who are small in relation to their due date or whose growth is not as fast as expected. This test can also detect pre-eclampsia.

Nuchal Scan

“Nuchal” means neck. This is a fairly new test that has been performed in a number of obstetric centres around Australia. It is considered a safe ultrasound scan that tests the baby’s neck development for any sign of Down’s Syndrome. Although it does not provide a definitive answer it can show at a very early stage if there is a chance your baby has Down’s. It may be the best non-invasive test available at the moment. If it shows a high risk, you may be offered amniocentesis or CVS.

Foetal Monitoring

This procedure may be used if there is any cause for concern. From around 35 weeks onwards, checking the heart of the foetus can be useful in assessing your baby’s wellbeing. An ultrasound disc is strapped to your abdomen and the foetal heartbeat is charted on tickertape and magnified through a loudspeaker.

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1. Confirming Pregnancy

These are performed with the help of an ultrasound scan to determine the baby’s exact positioning in the womb.

Amniocentesis

This test can be carried out from 14-26 weeks and involves passing a fine, hollow needle through the abdominal wall into the womb. A sample of amniotic fluid that containing cells shed by the developing baby is taken and the cells are then cultured in a laboratory. This process can take up to three weeks and the results are considered accurate. Some women may have a little leakage or bleeding and it is also common to experience mild cramps on the day. It is recommended that you rest for 24 hours following the procedure. There is a one in 200 risk of miscarriage after the test, which is lower than for CVS.

Chorionic Villus Sampling

The advantage of CVS is that it can be carried out as early as 11 weeks. The basic procedure is similar to amniocentesis except fragments of the placenta are extracted. These are then sent off for detailed analysis and the results are ready in about 10-14 days.

The whole process will take about 30 minutes although the procedure itself takes only five minutes. You are likely to have this test if you are aged 30 or over, if you wish to be tested for chromosomal abnormalities or inherited disorders, or if there is reason to test sooner than is possible with amniocentesis.

CVS can be uncomfortable, some women have vaginal bleeding or cramping for a day. The risk of miscarriage is one in a hundred.

Cordocentesis

This test can be carried out relatively late in pregnancy from 18-24 weeks when the umbilical cord has developed. The doctor inserts a needle through your womb and into one of the blood vessels in the baby’s umbilical cord. A tiny sample of blood is taken and analysed.

Questions to ask yourself before having an invasive test

• Are the results essential in deciding the course of my care?
• If I decided not to have the test how would this affect my pregnancy?
• If I am considered high risk and advised to have an invasive test, would I be willing to risk miscarriage to detect abnormality?
• If a test reveals an abnormality, would I be prepared to terminate the pregnancy?
• If I had a baby with mental or physical problems, could I deal with the extra demands placed upon me?

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1. Blood Tests
2. Confirming Pregnancy

There are a range of blood tests you can have including:

The Triple or AFP Test

This test is usually offered to women over 35 or those with a higher risk of having a Down’s Syndrome baby.
Carried out at14-20 weeks, it also assesses the risk of a neural tube defect such as spina bifida or anencephaly (when the foetal brain does not develop). The test shows the level of three substances found in the mother’s blood stream: alphafetoprotein (AFP), oestriol, and human chorionic gonadotrophin (HCG). This test alone does not provide a definitive answer but if the result is positive medical professionals consider that you have an increased risk of having a Down’s baby. To diagnose this further you would be offered an invasive test such as amniocentesis or cordocentesis.

Glucose Torlerance Test

This test for diabetes is used for women at risk of diabetes, particularly those who are known to have high blood sugar, sugar in the urine, diabetes in a previous pregnancy, or a large baby.
Usually carried out at 28 weeks, this test measures blood sugar levels. You will be given a high-sugar glucose drink and an hour later blood samples are taken to determine blood sugar levels.

HIV Test

Anyone at risk may ask to be tested however this is only performed with your consent. The test detects the presence of antibodies for the HIV virus. If you test positive, any infections that you develop must be treated carefully. Certain measures are taken at birth to minimise the risk of transmitting the virus to your baby and often a Caesarean section is advised.

Sickle Cell Anaemia Test

Advised for parents with ancestry originating from Africa and the West Indies. The test looks at the type of haemoglobin in your red blood cells and detects sickle cells. If the sickle cell trait is detected, your partner should be treated as well. If he is positive, the baby is at risk of being born with the disease. An amniocentesis or cordocentesis test will confirm this.

Haemoglobin Electrophoresis Test

Advised for parents with ancestry originating from Asia and parts of Africa, this test identifies the different haemoglobins in red blood cells that denote thalassaemia. If the test is positive, the baby may develop the disease. You may become anaemic and require iron and folic acid supplements.

Toxoplasmosis

Advised if you have had recent flu-like symptoms and have been in contact with pets and farm animals. It tests for antibodies to toxoplasma in your blood that suggest infection. If it is positive, antibiotics will be advised to treat the baby along with ultrasound scans to see if the baby’s development is being affected.

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1. Invasive Tests
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3. Gestational Diabetes