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Imaging Services >> Obstetric Ultrasound

The Obstetric Ultrasound and Fetal Medicine Unit offers both a Consultant and Sonographer led service. Using state of the art ultrasound equipment, you and your partner can share in the experience of seeing your baby grow and mark the milestones in their development as your pregnancy progresses. You may also choose to have a 3D / 4D scan to further enhance the excitement of seeing your baby as it grows.

Scan Type	Date for Scan
Early Pregnancy and Dating Scan	6 – 10 Weeks
Combined Screening Test	11 – 13 Weeks + 6 Days
Fetal Anatomy Scan	19 – 21 Weeks
3D / 4D	24 – 30 Weeks
Growth Scan	30 – 34 Weeks

Early Pregnancy & Dating Scan: The first early ultrasound scan provides you and your Consultant with important information regarding the number of babies and the expected date of delivery. The presence of a pregnancy and detection of the fetal heart can be seen from 6 weeks gestation by vaginal scan and from8-9 weeks by abdominal scan. Accurate measurements and images are taken of the gestational sac, the crown to rump length of the embryo, to accurately date the pregnancy, and assess the pelvic region to exclude pathology.
Combined screening test: The Obstetric Ultrasound and Fetal Medicine unit offers serum blood screening in early pregnancy in combination with nuchal scanning and maternal age in order to identify pregnancies at high risk of complications/abnormalities. The combination of these factors allows the detection of about 85% of Down's Syndrome cases and also those at high risk for Edwards Syndrome (Trisomy 18). This test is performed between 11-13 weeks gestation and if the results show an increased risk, a diagnostic test is offered such as chorionic villus sampling from 11 weeks or amniocentesis after 15 weeks.
Integrated test: The Integrated Test identifies pregnancies at a high risk of Down's Syndrome, open neural tube defects and Edward's Syndrome (Trisomy 18). This test detects 85% of Down's Syndrome cases although it does have a lower 'false positive' rate than the Combined test. The test is performed in two stages and the result is based on the data collected on both occasions. Stage 1 is undertaken between 11-13 weeks and comprises a blood test and an ultrasound scan. Stage two is undertaken ideally between 15-16 weeks and involves a second blood test. Women with a risk of 1 in 250 or greater are interpreted as screen-positive for Down's Syndrome and are offered a further diagnostic test such as a CVS or an Amniocentesis.
Chorionic Villus Sampling: A chorionic villus sampling diagnostic test (CVS) is performed between 11-14 weeks of pregnancy. Using ultrasound guidance, a sample of placental tissue is taken using a needle inserted through the abdominal wall or fine forceps through the cervix. The tissue collected is then tested for chromosomal abnormalities. Preliminary results are usually available within 2-3 working days with a full report available within 2-3 weeks.
Amniocentesis: An amniocentesis is performed later in pregnancy. Using ultrasound guidance, a sample of amniotic fluid is taken using a needle inserted through the abdominal wall. The fluid collected is then tested for chromosomal abnormalities. Preliminary results are usually available within 2-3 working days with a full report available within 2-3 weeks.
Fetal anatomy scan: Between 19-21 weeks the anatomy of your baby is scanned in detail so that any information about the many body systems, such as the urinary tract, digestive tract, heart and major blood vessels, brain and others, can be imaged and interpreted. The careful and accurate measurements made during the scan help to monitor the wellbeing of your baby.
Fetal cardiac scan: Consultation and scanning is available in our Fetal Medicine Unit for specialist scans of the heart and major blood vessels. This involves comprehensive real-time scanning and counselling to diagnose or exclude malformation of the heart.
3D / 4D scan: A 3D / 4D ultrasound scan focuses on your baby's face and facial features. It is not a diagnostic scan and therefore does not include measurements of fetal growth or weight. The success of the scan depends on the fetal position and gestation. Care will be taken to ensure that optimum images are obtained, however on occasions examinations may be unsuccessful and / or need to be rescheduled. A 20 minute VHS or DVD, CD with JPeg still images and some thermal images will be presented to you at the end of the scan. The Sonographer or Consultant performing the scan will be able to answer any further questions you may have.
FAQs: For a list of Obstetric FAQs please click here.