Fetal Assessment/Ultrasound

The Fetal Assessment/Ultrasound Department  is located on the 2nd floor of the hospital.

Opening Hours
Monday - Friday: 08.00 - 16.00hrs
Closed on public holidays

Tel: (01) 637 3217
E: scan@nmh.ie

Services Provided (see details below)

  • Early Pregnancy Assessment
  • Ultrasound Scans throughout Pregnancy
  • Fetal Medicine Consultations
  • Gynaecological Ultrasound

Click for current visiting guidelines.

Recording devices are not permitted

Early Pregnancy Assessment

The Early Pregnancy Assessment Unit in the Ultrasound Department is an appointment only service. Referrals are accepted from GPs and the maternity Triage service.

This is a midwifery-led service that is available to women less than 12 weeks pregnant and experiencing early pregnancy problems, such as vaginal bleeding and abdominal pain.

An ultrasound scan is performed externally (a transabdominal scan of the lower abdomen with a full bladder) or internally (a transvaginal scan with an empty bladder). An internal scan is usually required to examine a pregnancy less than 7 weeks. Depending on the scan results a blood test may be required.

Useful Downloads:
Ectopic Pregnancy 
Molar Pregnancy 

It is unsuitable for children to attend this appointment.

Recording devices are not permitted.

Anomaly Ultrasound Scan (The '20 Week' Scan)

The Anomaly Ultrasound Scan is offered to all women between 20-22 weeks gestation. The anomaly scan service is provided by specialist midwife sonographers and radiographers. The purpose of the scan is to check the health of your baby, assess the baby's growth, confirm your due date, assess the amniotic fluid volume and the location of the placenta (afterbirth). You do not require a full bladder for this scan. The scan takes 20-30 minutes to complete.

This scan checks for major physical abnormalities in the baby although it cannot detect every problem. In most cases, the scan will show that the baby appears to be developing normally. However, in some cases the sonographer will identify or suspect a problem that requries a referral to a fetal medicine specialist.

It may be difficult to get a good picture if the baby is lying in an awkward position or moving around a lot or if you are above average weight or your body tissue is dense.

This scan will be ordered by your midwife/doctor at your first visit appointment and you will receive an appointment letter by post. Please arrive on time for your appotinment.  If you need to reschedule this appointment please email our administrative team: scan@nmh.ie

It is unsuitable for children to attend this appointment.

Recording devices are not permitted.

Merrion Ultrasound is located at No. 60 Lower Mount Street, adjacent to The National Maternity Hospital.  This facility operates under the same guidelines and governance of the National Maternity Hospital and is for fee paying patients. If you are attending the semi-private clinic you will have the anomaly ultrasound here.

Ultrasound Scan After 22 Weeks

Following a normal anomaly scan ('20 Week' scan), another routine ultrasound scan appointment will not be made unless there is a clinical indication.

Clinical indications include pain, vaginal bleeding, reduced fetal movements, high blood pressure, low-lying placenta, a pre-existing medical condition, past obstetric history, a concern regarding the health of your baby, the baby's position, or if you are overdue, you will be referred for further assessment.

This follow-up ultrasound scan can be performed to examine the growth of your baby, the amniotic fluid and the placenta (afterbirth).

If there is concern regarding the development of your baby, you will be referred to a fetal medicine specialist for further assessment.

If your baby is small for gestational age you may have increased surveillance and attend for frequent scans to check the growth of your baby.

If you have a low-lying placenta you will have a follow-up scan at 34 weeks to identify the location of the placenta. You will require a full bladder for this scan. If the position of the placenta is unclear on the abdominal scan, then a transvaginal scan will be performed.

If your baby is in a breech position at 37 weeks you will be referred to the Breech Clinic for an ultrasound scan and review by a registrar and may have an external cephalic version (ECV).

If there is concern regarding fetal movements at/after 28 weeks gestation you will have a cardiotocograph (CTG) to assess the baby's wellbeing, and you may have a scan also.


Fetal Medicine

The National Maternity Hospital provides a referral service for maternal and fetal high risk pregnancies. We receive referrals from every obstetric department in the country. The service is provided by 6 sub-specialists in Maternal Fetal Medicine, with daily fetal medicine clinics attended by a fetal medicine specialist.  Consequently we can usually see urgent referrals within 24-48 hours of referral. 

Fetal Medicine Services include:

  • Prenatal diagnosis: first trimester screening and fetal anomaly scanning in the first and second trimester
  • Non-invasive Prenatal Screening: The Harmony Prenatal Test
  • Fetal Echocardiography in collboration with paediatric cardiology
  • Neurosurgical Clinics in collboration with paediatric neurosurgeons and neurosurgical nurse specialist
  • Renal Clinics in collboration with paediatric nephrologist
  • Surgical Clinics in collboration with paediatric surgeons
  • Invasive Tests: Amniocentesis, Chorion Villus Sampling, Cordocentesis
  • Fetal Therapy: Insertion of bladder or chest shunts, fetal blood transfusion
  • Rhesus Disease Management
  • Management of mulitiple pregnancy, including complicated monochorionic twins, laser ablation for twin to twin transfusion syndrome
  • Placental insufficiency assessment: assessment of fetal growth, maternal and fetal Dopplers

Contact Details for Fetal Medicine Clinics:
Mobile: (086) 028 5343
Fax: (01) 637 3436
E: fetalmedicinemidwife@nmh.ie

These clinics are busy and you may have a long waiting time so we advise against bringing children with you. Recording devices are not permitted.

Merrion Ultrasound is located at No. 60 Lower Mount Street, adjacent to The National Maternity Hospital.  This facility operates under the same guidelines and governance of the National Maternity Hospital and is for fee paying patients.


Gynaecology Ultrasound

A pelvic ultrasound scan is performed to examine the uterus and ovaries.

It is commonly performed for abnormal vaginal bleeding, postmenopausal bleeding, follicle tracking, absent periods, pelvic pain, follow-up of an ovarian cyst, location of an intrauterine contraceptive device or suspected fibroids.

There are two methods of performing pelvic ultrasound; transabdominally (through a full bladder) and transvaginal (via the vagina). For a transabdominal ultrasound you will need a full bladder for the scan and should drink 2-3 glasses of water one hour before the scan. For transvaginal ultrasound, no preparation is required. The examination generally takes about 20-30 minutes, The results will be sent to the referring doctor and will be discussed with you at your clinic appointment.

Transabdominal Ultrasound

For this type of scan you will be asked to drink fluid prior to the examination to fill the bladder, which is used as a “window” to examine the uterus and ovaries behind it. You will lie on your back on an examination couch, expose the lower abdomen where gel is applied and the transducer moved back and forth across your lower abdomen to take pictures. 

Transvaginal Ultrasound

This approach provides a more detailed view of the uterus and ovaries. You will be asked to lie on your back with your knees bent and legs apart (as if you were having a smear test or an internal examination). The sonographer will lubricate a small probe with gel and then insert this into the vagina. This may be slightly uncomfortable, but should not be painful. A transvaginal scan is routinely performed unless you feel it is not appropriate for you, you have never had sexual intercourse or an internal examination.