663 5060 ADDRESS: 60 Mount Street Lower, Grand Canal Dock, Dublin 2 info@merrionfetalhealth.ie
It may surprise you to know, that our Celtic relatives in Glasgow, were the first to use ultrasound back in 1956, for clinical purposes. The first prototype was developed by an engineer, Tom Brown, and an obstetrician, Ian Donald. Believe it or not the concept was based upon an instrument which was originally used to find flaws in ships. The team perfected its use for clinical purposes, and actually by 1960 Glasgow hospitals were using ultrasound routinely. Funnily enough it didn’t take off in American and British hospitals until the 1970s.

Of course since then ultrasound imaging has undergone an incredible amount of development, and by the end of the 20th century the majority of women in the developed countries of the Western world were going for routine pregnancy scans.

Today women in Ireland and other developed countries have come to expect ultrasound pregnancy scans as being an integral part of their pregnancy journey. In a way, we may have even come to take these pregnancy scans for granted a little bit, and maybe it is only at that moment when we are considering our first early pregnancy scan, that we may really give the technology more thought.



Due to recent developments of COVID 19 and following HSE guidelines,

patients are requested to attend ultrasound scans unaccompanied. This

includes partners, family members and children.


We would like to inform all patients that we remain open for ultrasound

scans as part of routine pregnancy care. We are closely following HSE

and NMH guidelines which are being constantly updated and developed.

These developments can be found via the NMH website. We remind our

patients that all our machines and ultrasound probes are always cleaned

thoroughly and disinfected with medical grade cleaning solution.

If you have any queries please do not hesitate to call in advance.


If you have flu-like symptoms or feel unwell, or if you might have been

exposed to the coronavirus, please contact us to re-arrange your

appointment. Call 663 5060.


For further information click through to go the HSE page
or you can go to our page that includes links to a selection of reliable resources - the HSE and others - click on: Coronavirus Pregnancy Rescources

Pregnancy scqans questions quick references

1. How many scans do you have when you are pregnant?

2. When should you go for your first pregnancy scan?

3. What months do you get ultrasounds during pregnancy?

4. Do you usually get an ultrasound in the third trimester?

5. How do you know how many weeks pregnant you are?

6. Is it bad to have a lot of ultrasounds during pregnancy?

7. What birth defects can be detected by an ultrasound?

8. Can you tell if a baby has Down syndrome in an ultrasound?

How many scans do you have when you are pregnant?

When are pregnancy scans offered in Ireland under the public health system? In Ireland, general best practice on our public health system offers two scans during pregnancy. Although some hospitals may have more limited resources in terms of scanner availability. However normally, you will be offered a pregnancy scan at 12 weeks and then around 20 weeks.

The early pregnancy scan at 12 weeks is to confirm that the pregnancy is viable, in other words that your baby is developing healthily.

This pregnancy scan confirms your baby’s heartbeat, while also checking if you are carrying multiples (twins or a larger number of babies). It also sites the pregnancy, confirming that it is your uterus. Gestational age is calculated during the early pregnancy scan. Gestational age is the age of your baby calculated from the date of your last menstrual period.

The anatomy scan, which is carried out around 20 weeks, examines your babys anatomy in great detail. This scan should hopefully confirm that your baby’s body is forming correctly. Sadly in some cases, abnormalities may be detected during this scan. For example problems with baby’s organs, limbs, spine, heart or brain can be detected.

When should you go for your first pregnancy scan?

If you are not considered high risk, or nothing abnormal has occurred during the first trimester of your pregnancy, then the first ultrasound is offered to you at 12 weeks in Ireland. This is called either a dating scan (as it calculates your baby’s gestational age) or an early pregnancy scan.

What months do you get ultrasounds during pregnancy?

In Ireland, women are normally offered a scan at the end of the first trimester, when they are 12 gestational weeks pregnant, so at the end of the third month. Then the second scan offered on the public health system is around 20 weeks, so about month five.

Do you usually get an ultrasound in the third trimester?

Unless there is some special reason to monitor your baby during the third trimester, you will not be offered a scan at this stage. However, women over 35 years of age may be offered a scan during the third trimester.

Of course if your obstetrician knows that there is a particular risk or need to monitor your baby’s development, you will be offered a scan at this time.

Another option that women in Ireland have, it to go semi-private. Some women do this for a variety of reasons. This article about this option is a useful read.

How do you know how many weeks pregnant you are?

The amount of weeks you are pregnant is actually calculated from the day of your LMP (last menstrual period). Here you can use the pregnancy due date calculator.

Is it bad to have a lot of ultrasounds during pregnancy?

Pregnancy ultrasound scans have been carried out for decades and up to now, there has been no evidence to suggest that they are harmful. The sonographer, who is the person who carrys out the scans, it highly trained to ensure that the scan is safe for you and your baby.

What birth defects can be detected by an ultrasound?

Some physical birth defects can be detected at the 20 week pregnancy scan. These include spina bifida, heart defects, some types of kidney problems, cleft palate in certain cases and absent limbs.

Can you tell if a baby has Down syndrome in an ultrasound?

During the 20 week ultrasound scan, it is possible to see fluid positioned on the back of a baby’s neck. This may indicate that the baby has Down Syndrome, however further tests need to be done, to make an accurate diagnosis.

Traditionally a woman then needed to have a nuchal translucency test. However there are some risks associated with this and these days, you have the option of a non-invasive test called the Harmony Prenatal Test. The Harmony Test doesn’t put you or your baby at risk.

Ultrasound pregnancy scans explained

So how does this technology work, that enables us to see our babies long before they come into this world to meet us?

Basically when you come in to a clinic for your scan, ultrasound waves will be aimed at your abdomen. These ultrasonic sound waves are bounced in order to get the images, so that an image of your baby’s body and structure can be generated. In the early days of fetal ultrasound it was only possible to see the baby’s head. However as more expertise was gained, clinicians were able to discern many more features.

Pregnancy scans can be very emotional

Even though we may have come to take them a little for granted, going for a pregnancy scan can be a huge emotional experience. Each scan can be a combination of being nerve wracking, exciting and emotional – and some women experience this to be even more dramatic in their first pregnancy, and of course in the early stages of any pregnancy.

In the majority of situations pregnancy scans are both reassuring and somewhat magical. Unfortunately a smaller percentage of women will experience pregnancy scans which are not reassuring. This can happen in a variety of scenarios, such as when the sonographer not been able to detect a baby’s heartbeat, or has seen possible abnormalities during the scan. Any of these situations are obviously heart-wrenching, and depending on the circumstances, the scan may help to prepare a woman and her partner to accept whatever the news is.

However in most cases pregnancy scans are a happy occasion. There is something about seeing a developing fetus that is almost impossible to explain, but it is truly an amazing experience. This is the case even when we attend someone else’s scan, as I have done previously. In that particular case, it seems like the baby was waving at us, and actually she was delivered around 24 hours later, a few weeks early.

Are ultrasound pregnancy scans safe?

The procedure of an ultrasound pregnancy scan is non-invasive. Millions of women have had pregnancy scans, safely and although concerns have surfaced from time to time, the experts are confident that ultrasound is safe.

Choice of pregnancy scans explained

Just below you’ll see our colourful icons along with the names of the various pregnancy scans that are available to you. Click on any of those to read more about the scan itself, and in some cases one of the consultants has filmed a video which also explains about the scan.

Additionally we can offer the Harmony Prenatal Test, which you can read more about by clicking on the banner further below, or the link in this sentence.


Nuchal Translucency

12-14 weeks


Anatomy Survey

18-22 weeks


Later Dating

12-17 weeks


Gender Scan

19 weeks onwards


Growth & Well Being

22 weeks onwards


Post Dates & Liquor

40 weeks onwards


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About The Clinic

Merrion Fetal Health Pregnancy Scans Dublin 2

About The Consultants

Dr. Rhona Mahony

About The Team

Pregnancy scans lead sonographer at Merrion Fetal Health

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18 weeks pregnancy scan facial profile Merrion Fetal Health

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