The Philosophy of Mater Mothers Hospital

Care for baby, mother and family is a balance of education and support through diagnostic tests, research clinical and midwifery expertise. While most pregnancies lead to the birth of healthy babies—health and development of mother and baby is improved with greater understanding of fetal development and pregnancy management.

Antenatal diagnostic testing is routinely undertaken in major obstetric-maternity hospitals. Mater Mothers’ Hospital recognises that medical technology advances rapidly. As a leading tertiary institution we are obliged to educate the community about new developments in medicine and provide high quality service with counselling and support.

Mater Mothers Hospital offer antenatal screening and testing services to women with concerns about risks to their unborn baby. We offer these services in the hope that concerns can be alleviated or something can be done to help the baby while still in utero, at delivery or immediately after birth.

Why is ultrasound performed in pregnancy?

Two main reasons are:

• screening—a routine test to confirm pregnancy dates and the number of babies, to check baby’s physical development and to identify possible problems or potential birth defects
• diagnostic—to identify problems causing symptoms in pregnancy such as bleeding, abdominal pain or slow growth.

Ultrasound screening (like cervical smear and breast cancer screening) helps to identify problems early. It allows time for care, management and effective treatment should an irregularity be detected.

First trimester screening program

The following information will help you understand what first trimester screening involves and how it can assess your unborn baby’s health and development.

Why is ultrasound screening offered in the first trimester?

First trimester nuchal translucency (NT) ultrasound is a non-invasive screening method used to identify babies with an increased risk for chromosomal abnormalities such as Down syndrome.

This assessment is done between 11+0 and 14 weeks gestation by measuring the thickness of a skin fold at the back of the neck called the NT.

The baby’s length, NT and your age are combined to calculate your baby’s risk level of Down syndrome (Trisomy 21).

A blood test measuring two hormones (PAPPA and HCG) can also be taken. If used together with the ultrasound measurements it can improve accuracy of the test. The detection rate for Down syndrome using NT and your age is 75-80%. By adding the blood test results, the detection rate is 85-90%. However it is important to remember that not all babies with a chromosomal abnormality will be detected by this method as the detection rate is not 100% guaranteed using either technique.

How is the scan result interpreted?

After the examination, results are explained to you. In 95% of women this risk will be reduced.

If the blood test has been performed, the combined result will be given to you at your appointment. If you do not wish to have the blood test performed the result of the ultrasound will be explained to you at the completion of the examination.

If the blood test is desired, it can be taken after the examination. The screening results will not be available immediately. We provide a phone number for you to call for results, usually within a week.

A report will be provided for you when results have been calculated and a copy sent to the doctor who referred you.

If your baby’s risk is high, further diagnostic tests will be fully discussed with you. Genetic counsellors are available to discuss high-risk results. You can choose to proceed to the diagnostic test at any stage.

Occasionally during the ultrasound scan, images are not clear enough for a variety of reasons. The scan may need to be performed using a vaginal ultrasound probe. This may cause some discomfort, but should not be painful.

Staff have undertaken special training and accreditation in ultrasonography for first trimester screening. The benefits of "seeing" your baby early and being reassured that all is well (in 95% of cases) needs to be balanced against the possibility (for five percent of patients) of finding potential problems with your baby. We understand this could be a stressful time for you and your family.

First trimester ultrasound screening is a new medical development. There are still many questions we may be unable to answer. Your doctor will help you understand the benefits, risks and options. If you would like to discuss your concerns with our Maternal Fetal Medicine team before deciding to have first trimester screening, you are welcome to contact us during listed business hours on +61 7 3163 1896.

Ultrasound scanning is a low-risk procedure, but more than one scan early in your pregnancy is usually unnecessary. We recommend another scan be performed at 18-20 weeks to check for other irregularities which may not be detectable before 14 weeks, such as spina bifida. Your doctor will refer you for this scan closer to the time.

Is a First Trimester Screening appointment appropriate for me?

Until recently, diagnostic tests for fetal abnormalities were only offered to women aged 35 years or more as the risk of having a baby with problems increases with mother’s age. However, first trimester ultrasound screening is appropriate for women of all ages who:

• are aware of an increased risk of problems based on previous pregnancies and hereditary knowledge
• have concerns about their unborn baby.

How does first trimester ultrasound screening compare with other antenatal diagnostic tests?

Ultrasound is a non-invasive screening method. It is different from diagnostic tests such as Amniocentesis and Chorionic Villus Sampling (CVS), where a needle is inserted into mother’s abdomen. CVS is performed from 11 to 14 weeks and amniocentesis from 16 weeks.

These tests are offered to mothers more likely to be carrying babies with chromosomal or other problems. They are offered to clarify results of ultrasound scans. Amniocentesis and CVS both carry a small risk of miscarriage.

How do I access the First Trimester Ultrasound Screening Program?

Patients must be referred by an Obstetrician or a General Practitioner for this service between 11 to 13 weeks of pregnancy. To make an appointment, please call +61 7 3163 1896 between 8.30am and 4pm, Monday-Friday. Please bring your referral form with you to the appointment.

Chorionic villius sampling (CVS) and amniocentesis

Why have I been offered this test in my pregnancy?

It is possible to diagnose a number of birth defects in pregnancy. These include:

• chromosome abnormalities e.g. Down syndrome
• inherited disorders e.g. cystic fibrosis.

Early detection of a birth defect allows parents to discuss how they want to manage a pregnancy and cope with information. It is your decision to proceed to testing.

What are some of the reasons that I might choose to have a test?

Women of 35 years of age or more have an increased risk of having a baby with a chromosome problem, the most common being Down syndrome. Babies with Down syndrome can be born to mothers of any age, although the risk slowly increases when the mother is in her late 30s or over 40. The risk at 35 is sufficient to warrant this test.

A family history of a chromosome problem and investigation may show that a prenatal test is appropriate.

A known disorder in the family which can be passed on to your baby (e.g. cystic fibrosis, muscular dystrophy) is an appropriate reason. There may be specific tests available for some disorders. For these families, genetic counselling and investigation are preferably performed before becoming pregnant.

If unexpected problems are detected on an ultrasound scan in early pregnancy, further tests may be appropriate. Your doctor, midwife, genetic counsellor or geneticist will discuss the findings with you. Further tests may be offered to help clarify the nature of the problem.

Is counselling available before I have a test?

Counselling is recommended before any test is performed. This may be carried out by your doctor or a genetic counsellor.

Issues that you might like to discuss include:

• which tests are available and most suitable
• a thorough explanation of the test procedure
• how long results will take and how you will receive them
• the choices available if a problem is detected
• attitudes and personal beliefs about testing and the possible outcomes.

What is ultrasound?

Ultrasound is high frequency sound that is passed into the body from an ultrasound probe and reflected off the internal organs. An ultrasound machine changes these sound waves into visible images on the screen.

Chorionic villus sampling (CVS)

CVS allows us to take a small sample of tissue, the chorionic villi, from the developing placenta. CVS is one of the two tests available to check the chromosomes (the structures that contain genes) of the baby. This tissue may also be used for biochemical or direct genetic testing.

CVS is performed at 11-12 weeks in the pregnancy and is a day patient procedure.

An ultrasound will be performed first to check how far pregnant you are, and to show the position of the baby and the developing placenta. As the baby is small and not fully developed, very few physical problems can be detected at this stage by ultrasound scan. Your bladder should be full but need not be uncomfortable.

CVS Procedure

Chorionic villi can be obtained by inserting a needle through the mother’s abdomen (which has been cleaned with antiseptic and numbed with anaesthetic) under ultrasound guidance into the developing placenta. A small sample of chorionic villi is withdrawn.

The chorion villus sample is sent to the laboratory for testing.

A chromosome result will be available in one to two weeks.

A biochemical or direct genetic (DNA) test may take longer.

CVS carries a small risk of causing a miscarriage. The average risk is up to one chance in 100.

The chromosome test establishes the sex of the baby and if you wish to know this information you must ask the person who gives you your result.

Amniocentesis (Amnio)

What is Amniocentesis (Amnio)?

Amniocentesis is the removal of a small amount of amniotic fluid from the sac around the baby.

This fluid contains cells which come from the baby and the placenta. This test is usually performed at 16 weeks into the pregnancy.

Amnio Procedure

After cleaning the skin with antiseptic, a fine needle is inserted under ultrasound guidance through the mother’s abdomen into a pool of amniotic fluid. A small amount of fluid is withdrawn and the needle removed. The amniotic fluid is sent to the laboratory for testing. A chromosome result will take 2-3 weeks. A biochemical or direct genetic (DNA) test may take longer.

The chromosome test establishes the sex of the baby and if you wish to know this information you must ask the person who gives you the result.

Amniocentesis carries a small risk of causing a miscarriage. The average risk is up to one chance in 100.

Are the procedures painful?

Most women say amniocentesis is not painful. However, some women feel discomfort. Some women experience discomfort during and after CVS.

For both tests it is advisable to rest for the remainder of the day. You may like to have your partner, a family member or friend with you on the day of the test.

Another popular idea is to bring along a hand-held CD player or “walkman” with earphones to help you relax.

What will happen after the test?

There is a risk of naturally occurring miscarriage in all pregnancies. The risk is highest in early pregnancy and increases with the age of the mother. The risks quoted for prenatal tests are in addition to this naturally occurring risk of miscarriage.

Most people have normal results after the test. However, if the test shows the baby to have a problem, you will have the opportunity to discuss the results with your doctor, genetic counsellor or geneticist.

It is important to realise that while the combination of ultrasound scan and CVS or amniocentesis goes a long way towards identifying your baby as normal, it does not guarantee that every possible abnormality has been excluded.

What is the Philosophy of Mater Mothers’ Hospital?

Antenatal testing is routinely undertaken in all major obstetric-maternity hospitals. We, too, offer this service to women who may have concerns that the unborn baby is at risk of suffering from some major abnormality. We offer the test in the hope that these concerns can be alleviated, or that something can be done to help the baby while still in the uterus, at the time of delivery or immediately after the birth.

In keeping with Catholic Church teaching and the philosophy of the Hospital, termination of pregnancy is not provided at Mater Mothers’ Hospital. We do offer a full range of pastoral care, ethical advice and counselling support to supplement medical and nursing services to all women and their families. Please ask one of the staff to help you arrange an appointment if you would like to access these services.