637 4060 ADDRESS: 60 Mount Street Lower, Grand Canal Dock, Dublin 2 info@merrionultrasound.ie

Merrion Ultrasound, formerly Merrion Fetal Health

A Centre Of Medical Excellence: Midwife/Sonographer Facilitated

Pregnancy Scans Dublin 2 at Merrion Ultrasound

Pregnancy Scans For All Stages Of Pregnancy

Merrion Ultrasound offers ultrasound pregnancy scans Dublin for all stages of pregnancy, from your first early pregnancy scan to a nuchal scan or a growth and well being scan.

Additionally, the clinic offers the Non-Invasive Pre-Natal Test.


Follow-On Treatment Can Be Arranged

Follow on treatment can also be arranged. Further below are the icons that lead to the various scans that we offer, or these can also be accessed from the drop-down menu above. For an informational video and some recent pregnancy ultrasound scan videos – click on Pregnancy Scan Videos.

Loyalty Scheme Pregnancy Scans Dublin

Conveniently located in Dublin 2, the clinic offers a loyalty scheme, which means you can get a €30.00 discount on full-priced third and subsequent scans during the same pregnancy. The loyalty scheme does not cover the NIPT formerly the Harmony Pre-Natal Test or Nuchal Fold Scans.

Merrion Ultrasound is open to all women not just those attending the National Maternity Hospital.



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Choose Merrion Ultrasound For Pregnancy Scans Dublin, Non-Invasive Pre-Natal Test and Gynaecological Scans

For peace of mind, Merrion Ultrasound Health is medically led and midwife/sonographer facilitated.

Merrion Ultrasound is a consultant led ultrasound clinic, located in Dublin 2, where follow-on treatment is an option if you so wish.


Nuchal Translucency

12-14 weeks


Anatomy Survey

21-22 weeks


Later Dating

10-17 weeks


Gender Scan

19 weeks onwards


Growth & Well Being

22 weeks onwards


Post Dates & Liquor

40 weeks onwards

Some Common Pregnancy Scans Questions


If you are wondering why you should have an early pregnancy scan, why not take a look at this video where one of our consultants, Professor Shane Higgins, explains clearly the reasons for attending an early pregnancy scan – just click on Early pregnancy scan video


When Can I Have An Early Pregnancy Scan?


Especially if this is your first pregnancy, you may also be unsure as to when is the earliest you could have your first scan. Normally this 1st-trimester scan is undertaken from 6 to 12 weeks. These weeks refer to the gestational age of your baby, and what this means is that the date is taken from your last period. However, we often recommend leaving this scan until after 7 weeks if possible, because at this stage we can normally get more accurate information at your scan.


Main Reasons To Go For An Early Pregnancy Scan


One of the main reasons to undertake this scan is to confirm if your baby’s heartbeat is present. Also, this first pregnancy scan is when we should be able to see how many babies are in your uterus, for those of you who are pregnant with multiples. Of course, you will want to know your estimated due date, and we can also give you this information at the early pregnancy scan. Finally, we can check where the baby/babies are located. Sometimes baby could be located in the fallopian tubes and this can be determined at this time. This is called an ectopic pregnancy.



Nuchal Fold Scan-Nuchal Translucency Test


If you have heard the term nuchal fold scan but aren’t entirely sure what this scan entails and whether you should have one, then read on. Many women know of this scan as the test for Down’s Syndrome. 

If a fetus has an extra chromosome, he/she may have extra fluid, in the area at the base of his/her neck. This is the spot which is called the nuchal fold. The sonogram can measure this fluid between the 11 to 14 week period, and it may make the fetus? neck larger. As well as the scan, you will go for a blood test, which you will ideally do around 10 days before you come into the clinic for your scan. If you have been able to come in 10 days before the scan, then we should be able to give you the result on the day of your nuchal scan.



Understanding The Results


When you get the result, you will be told a number such as 1 in 100, 1 in 500, 1 in 5000, and depending on the result you can then decide if you should go for a more definitive diagnostic test. Our team will, of course, help you fully understand the implications of your result.


Non Invasive Pre-Natal Test


Would you like to know more about the Non-Invasive Pre-Natal Test? Then head over to the page that explains the Non-Invasive Pre-Natal Test.


Comprehensive Pregnancy Scans FAQs

What Can I Expect At My Early Pregnancy Scan at Merrion Ultrasound?

A full bladder is required for this scan. On occasions, it will be necessary for an internal ultrasound examination to be performed. On occasions, it is possible that you will receive an inconclusive scan result. This is normally due to the fact that it is simply too early to see the pregnancy or the pregnancy is not growing as it should.

If, at your appointment it is not possible to confirm whether your pregnancy is ongoing or not we will recommend that you be rescanned in 7 – 10 days’ time. There will be a charge of €60.00 for subsequent Early Pregnancy/Reassurance scans. A scan in early pregnancy is usually performed in the first trimester between 6 – 12 weeks gestation. You may be having a scan for a number of reasons including confirmation of the EDD (estimated date of delivery), to confirm the pregnancy or just for peace of mind. You may have a scan earlier than this if you are experiencing complications in the pregnancy such as bleeding.

When arriving at Merrion Ultrasound you will be met by a member of our Administration Team. If it is your first time with us you will be asked to complete a registration form. You will then be directed to our waiting room where you will await your sonographer. Your sonographer will meet with you in the waiting area and take you to the ultrasound room. Your registration details will be confirmed with by the sonographer before the ultrasound procedure begins.

There are two types of early pregnancy scans; an abdominal scan and a transvaginal scan. An abdominal scan is performed by placing the transducer onto the abdomen of the patient. A lubricating gel is used to facilitate the scan. The process of abdominal scan is non invasive and painless. You will be required to have a full bladder for an early pregnancy scan. Drinking about one pint of water one hour beforehand is normally sufficient to fill the bladder but stop drinking if you start to feel uncomfortable. A transvaginal ultrasound can detect earlier pregnancies. It is often necessary for the sonographer to perform a transvaginal scan (TVS) in very early pregnancy. A TVS involves the insertion of a probe into the vagina. Transvaginal ultrasound gives a much clearer and enhanced view. If the sonographer feels it necessary to proceed to a TVS the procedure will be discussed with you and your permission sought. Like an abdominal ultrasound, a TVS is not painful but maybe a little uncomfortable and possibly a little embarrassing.

What Will The Sonographer Check?

When the early pregnancy scan is being performed your sonographer will:

  • calculate the gestational age
  • check for a fetal heart
  • determine the estimated date of delivery
  • look for multiples
  • will check to exclude an ectopic pregnancy

The ultrasound is available for you to view on a 42” screen which is located on the wall at the end of the ultrasound couch. This allows you to view the images produced by the transducer. At this stage in pregnancy it may not be easy for you to make out what you are seeing on screen but the sonographer will explain what you are looking at.

It is our aim to make your visit with us as relaxing, enjoyable and as stress free as possible. If you have any questions before, during the early pregnancy scan or after your visit please do not hesitate to ask a member of staff and we would be delighted to assist with your query.

Can you see a 2 week pregnancy on ultrasound?

It can be possible to site a gestational sac as early as three weeks from conception, which is five gestational weeks of pregnancy. If a sac is not present, it could be that the mother-to-be has ovulated later than normal. If tests show that the HcG is 1100, an ultrasound may be repeated a few days later. In most cases ultrasound is not carried out at such an early stage.

Can you see the baby at 4 weeks?

At four weeks of gestational pregnancy, the ball-like formation of cells is forming into embryo (the stage before fetus) and placenta. Therefore if an ultrasound were to take place, the gestational sac may show, looking a bit similar to a tiny dot. In most cases ultrasound is not carried out at such an early stage

What can be seen on ultrasound at 5 weeks?

At five gestational weeks of pregnancy, three weeks from conception, it is possible to see the tiny dot, which is the gestational sac. In most cases ultrasound is not carried out at such an early stage.

Can you feel an unborn baby’s heartbeat?

During pregnancy, you may think you feel your unborn baby’s heartbeat, when your blood vessels in your tummy pulsate. This is a common mistake to make. However you don’t actually feel baby’s heartbeat at all during pregnancy.

Can I have a scan at 6 weeks?

Generally this is the earliest a scan will be performed. The six weeks are dated from the date (first day) of your LMP (last menstrual period). Your medical team will recommend a scan if you have experienced pain, bleeding or any other symptoms, that mean that it will be better to confirm viability (if your pregnancy is viable, meaning that your unborn baby has a heartbeat).

Can you see the heartbeat at 6 weeks?

The heartbeat of an embryo normally starts off at six weeks of gestational pregnancy (dated from the first day of your LMP). This is detected by carrying out a transvaginal ultrasound. Sometimes it isn’t possible to detect your embryo’s heartbeat until around seven or eight weeks of gestational pregnancy. So you may need to attend the clinic for another scan.

Can you see a baby on an ultrasound at 7 weeks?

In general by seven weeks it should be possible to confirm your embryo’s heartbeat, although in some cases it may only be possible to detect the following week.

What week do you find out the gender of the baby?

If you choose to find out your baby’s gender, then this can normally be detected between week sixteen and week twenty. However this will depend on how the ultrasound goes, in terms of the sonographer being able to see the baby’s genitalia. This depends on how baby is positioned.

What is an anatomy scan?

The anatomy scan is normally carried out between weeks 21 and 22 and it is considered a level 2 ultrasound. Essentially, this is a more detailed ultrasound. The sonographer should be able to tell you the sex of your baby if you wish. She/he will take a number of measurements during the scan in order to check that your baby is growing normally

How long does it take for an anatomy scan?

An anatomy scan normally takes between 30 to 45 minutes to perform, and this depends on how your baby is lying and how much she cooperates.

What is a Level 2 ultrasound?

A Level 2 ultrasound is a scan that goes into a more detailed analysis of the fetus. The fetal anatomy and its development are evaluated during the scan which typically takes between 30 to 45 minutes to perform.

What can I expect at my Anatomy Survey scan?

At your anatomy survey pregnancy scan, you can expect that the sonographer will check the following:

  • to determine the position of the baby
  • to determine the location of the placenta
  • to check the amniotic fluid around the baby
  • to monitor the growth of the baby to ensure that it is growing normally


How should I prepare for my anatomy survey scan?

This scan is also referred to as the routine scan or anatomy scan. This scan essentially examines the baby’s anatomy in a detailed manner and is carried out between 21 and 22 gestational weeks. The sonographers ask patients not to empty their bladders before their scan as it allows for better ultrasound images  When you attend the Merrion Ultrasound Clinic for an anatomy survey scan, it is quite possible that you may have been at the clinic for an early pregnancy scan, but if you have not been with us before then you will fill out a registration form when you arrive.

You will await your sonographer in the waiting room. Your sonographer will bring you to the ultrasound room and confirm your details before performing the ultrasound scan. Lots of the time your sonographer will be examining anatomical details of your baby which are not obvious to you. The sonographer will check all your baby’s organs and take measurements and images. She will check your baby’s face, baby’s spine, baby’s abdominal wall, baby’s heart, kidneys and stomach. Your baby’s arms legs, hands and feet will also be checked. Measurements of the baby’s head circumference, abdominal circumference and femur will be taken.

As well as checking how your baby is growing the sonographer will check the placenta, the umbilical cord and the amniotic fluid. The team at Merrion Ultrasound wish to ensure that your visit is as relaxing as possible and we welcome any questions, so please do not hesitate to ask your sonographer any questions you may have.

Can I ask to find out what gender my baby is at the Anatomy Scan?

At around 19 weeks it can be possible to tell the sex of the baby at this scan, but it is not always. The baby may not be in a favourable position to determine the gender. However, if you would like to know the gender of your baby please inform your sonographer at the beginning of your ultrasound. Determining the sex of the baby is not always an easy job as we are depending on the baby to be in a position that allows us to visualise the genital area and the baby does not always oblige.

What will happen if a problem is suspected during the anatomy survey scan?

If at the time of scan a problem is suspected, you will be told at that stage that there may be a problem. A full discussion of the problem may require you to come back for further scanning and a discussion with one of our fetal medicine specialists. This can usually be organised within 24 hours if the problem is deemed urgent. Most problems that need repeat scanning are not serious and approximately 15% of scans will need to be repeated for one reason or another. At the end of your scan you will be given images of your baby and a detailed report on the findings of your scan. A copy of this report will be sent to your obstetrician and/or GP as required.

To book an Anatomy Survey Pregnancy Scan please call (01) 663 5060 or use the Make a Booking online form. This scan is from 21 weeks to 22 weeks. Merrion Ultrasound is conveniently located in Dublin 2 and offers ultrasound for all stages of pregnancy including early pregnancy scans, nuchal scans, anatomy and growth scans. Merrion Ultrasound is open to all women not just those attending the National Maternity Hospital.

How early is it possible to tell baby’s gender with a gender scan?

The gender scan is carried out from 18-21 weeks of pregnancy. However, this scan is often referred to as a 20-week scan or an anatomy survey scan. Its main purpose is to check that baby is growing as he should be and at the same time to check if there are any signs of physical abnormalities.

It is a personal decision if you wish to find out the gender but if you do, you should tell the sonographer before the scan.

How accurate is a gender scan?

Gender scans have an accuracy rate of 85%.

Should I find out my baby’s gender?

This is a very personal decision. Some Mums-to’be are happy to wait until the day of the delivery. Many like to know also and of course, this can help in making decisions such as clothes, toys and nursery decorations.

Can a Mum-to-be know or feel her baby’s gender before this scan?

In a 2017 study, entitled Maternal Intuition of Fetal Gender, the team stated the following:

“We have observed anecdotally that the vast majority of pregnant women presenting to our obstetrics clinic for second-trimester ultrasound screening request gender identification. At these visits, many mothers-to-be say they can perceive or “feel” the gender of the unborn baby.”

What To expect during my gender scan at Merrion Ultrasound

Gender scans can be carried out from 19 weeks onwards, and have an 85% accuracy rate. This scan aims to determine the gender of your baby, and will also try to estimate fetal weight. This scan will look to determine the presentation and lie of the baby, the location of the placenta, and measure the fluid around baby. Blood flow to baby’s umbilical artery will be measured, and the scan will look for any abnormalities.

When you attend the Merrion Ultrasound Clinic for a gender scan, it is quite possible that you may have been at the clinic for a previous pregnancy scan, but if you have not been with us before then you will fill out a registration form when you arrive. You will await your sonographer in the waiting room. Your sonographer will bring you to the ultrasound room and confirm your details before performing the ultrasound scan.

The team at Merrion Ultrasound wishes to ensure that your visit is as relaxing as possible and we welcome any questions, so please do not hesitate to ask your sonographer any questions you may have.

What is a growth and well-being scan?

The growth and well being scan is one of the scans we offer in pregnancy. It assesses the baby’s growth and we can do it from twenty four weeks to term.

What is checked at a growth scan?

With this scan we check where the placenta is, we look at the fluid around the baby and we measure the size of the baby. We can also look at the blood flow in the umbilical cord and it’s something we do from twenty-two weeks right through to term.

Why would you need growth scan?

Some of the common reasons to attend a clinic or hospital for a growth and well-being scan are:

  • An abdomen that is either bigger or smaller for the stage of pregnancy
  • High blood pressure
  • Women who have had complications in previous pregnancies
  • Diabetes

How long does the growth scan take?

Around 30 minutes but it is best to give yourself more time.

Do you get pictures at a growth and well-being?

Yes, you do.

What risks are associated with the Non Invasive Prenatal Test (NIPT)?

The testing is non-invasive: it involves taking a blood sample from the mother. The pregnancy is not put at risk of miscarriage, or from other adverse outcomes that are associated with invasive testing procedures such as amniocentesis.

How accurate is the NIPT by The Doctors Laboratory?

NIPT provides fewer false-positive and false-negative results than combined first trimester screening for trisomy 21, 18 and 13.

It is important to note that NIPT is a screening test and does not provide a definitive genetic diagnosis, as NIPT cannot differentiate potential chromosome differences between the placenta and fetus. A definitive genetic diagnosis of the fetus requires cytogenetic analysis of either amniotic fluid or chorionic villus sampling (CVS).

Combined first trimester screening 82% 1 in 26
NIPT >99% <1 in 1,000
Accuracy (T21, T18, T13) Sensitivity* False-positive rate#

* Proportion fetuses with trisomy correctly identified by the test as high probability of disorder.

# Proportion of normal fetuses incorrectly identified by the test as high probability of disorder.


NIPT Performance data in a general screening population
Trisomy 21 >99.9% (95% CI:97.1%) >99.90% (95% CI:99.63%)
Trisomy 18 >99.9% (95% CI:91.4%) >99.90% (99.64% CI:97.1%)
Trisomy 13 >99.9% (95% CI:87.1%) >99.90% (95% CI:99.64%)

Who can have this test?

NIPT can be ordered by healthcare professionals for women with pregnancies of at least10 weeks’ gestational age. This test can be requested for any singleton or twin pregnancy, including those conceived naturally or by IVF using the patient’s own egg or a donor egg.

Note that, in twin pregnancies, sex chromosome (X and Y) analysis can determine fetal sex but not sex chromosome conditions. This test is not suitable in the case of a vanishing twin. The sex of twins will be reported as one result. If male, one or both of the twins will be male. If female, both twins will be female.

The test does not assess risk for mosaicism, partial trisomies or translocations.

Why might a repeat sample be necessary for the NIPT?

There needs to be enough fetal DNA in the maternal blood to be able to provide a result. If there is insufficient fetal DNA in the sample (which occurs in 2% of cases), another blood sample from the mother may be required. This will be processed in the laboratory at no extra charge.

What happens at the Non-Invasive Prenatal Test?

Once the mother has taken an independent personal decision that she wants to have the NIPT (non-invasive prenatal test) performed, she will be asked to sign a consent form and her blood sample can be taken from a vein in her arm

Who carries out the analysis of the Non Invasive Pre-Natal Test?

The mother’s sample and completed request form need to be sent to TDL Genetics, where the test is performed on the DNA extracted from her blood sample.

Will the Mum-to-be need to have any other test?

NIPT does not provide information on mosaicism, partial trisomies or translocations, or other rare chromosomal abnormalities. If the ultrasound scan shows a high nuchal translucency or other major physical defects such as brain abnormalities, heart abnormalities, the risk for some rare chromosomal defects may be high. In such cases, the mother may choose to have a CVS or an amniocentesis.

The non-invasive prenatal test does not provide information on other physical defects such as spina bifida, or information on fetal growth. It is therefore advisable that the mother has all the usual ultrasound scans during her pregnancy.

What is Trisomy 21?

Trisomy 21 is the most common trisomy, at the time of birth. Also called Down syndrome, it is associated with moderate to severe intellectual disabilities and may also lead to digestive disease, congenital heart defects and other malformations.

What are Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome)?

Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome) are associated with a high rate of miscarriage. These babies are born with severe brain abnormalities and often have congenital heart defects as well as other birth defects. Most affected individuals die before or soon after birth, and very few survive beyond the first year of life.

What are sex chromosome conditions?

The sex chromosomes (X and Y) determine whether we are male or female. X and Y chromosome conditions occur when there is a missing, extra, or incomplete copy of one of the sex chromosomes. The Harmony with X, Y test can assess risk for XXX, XYY, XXYY, XXY (Klinefelter Syndrome), and a missing X chromosome in a girl (Turner Syndrome). There is significant variability in the severity of these conditions, but most individuals have mild, if any, physical or behavioural features.

If the mother is interested in having this optional testing, she should talk with her healthcare provider to determine if it is right for her.

X & Y chromosome conditions are only checked upon request.

What is a later dating pregnancy scan?

A later dating pregnancy scan is carried out during the first few weeks or so of the second trimester for reassurance.

What kind of information will I receive during a later dating scan?

You will learn about your baby’s wellbeing and how the parts of the body are developing at this time. This scan can also offer a relatively accurate due date if you didn’t manage to attend us for an early pregnancy scan.

Baby’s heartbeat will be verified as viable during this scan. The location of your baby will also be checked.

We will also check the placental site.

Who performs your nuchal fold scan?

The ultrasound portion of the Nuchal Translucency test is done by a sonographer/obstetrician or radiographer who is trained for this specific screening.

How do you prepare for a nuchal scan?

There is very little preparation needed. You should have some fluid in the bladder but not be uncomfortably full. Drinking fluids prior to the examination will enlarge the bladder. The bladder is used as an acoustic window to improve the image quality and it also improves the position of the baby. It is a good idea to wear comfortable clothing that gives easy access to your lower abdominal area.

How is the nuchal scan performed?

The scan is performed by applying a warm gel over the patient’s lower abdominal area. A transducer (a smooth handheld device) is moved gently across the abdomen with a sliding and rotation action to scan the baby through the tummy. It can sometimes be difficult to accurately measure the Nuchal Translucency because of the position of the fetus. In this case, the sonographer/radiographer will explain that a transvaginal ultrasound is needed and will request your permission to do so. A transvaginal ultrasound involves a small specially shaped transducer to be inserted into the vagina. Because the transducer is closer to the fetus it can provide clearer images.

What are the risks associated with the nuchal translucency test or nuchal fold scan?

There are no known risks to performing trans-abdominal ultrasound which uses sound waves to obtain pictures or images. There is no radiation involved. Nuchal Translucency testing is non-invasive and poses no risk to the foetus or similarly no risk to you or of miscarriage. Should you have First Trimester Screening (FTS)? Only you can decide whether or not to have FTS. To book a Nuchal Fold Scan please call (01) 663 5060 or use the Make a Booking online form. This scan is from 11 weeks to 14 weeks.

What is a thick nuchal fold?

When the nuchal fold has a thickness of over 6 mm, the baby is considered to have a high chance of fetal abnormalities such as Down’s Syndrome, heart problems and other anomalies.

Usually, the nuchal fold grows in proportion to the developing baby. For example, when a baby measures between 45 to 84 mm (1.8 to 3.3 inches), a nuchal fold of under 3.5 mm would be considered to be within the normal range.

What is normal nuchal translucency?

The nuchal translucency normally develops in proportion to the growing baby. 90% of babies with an NT measurement within the range of 2.5 mm to 3.5 mm will not develop Down’s Syndrome.

What is normal nuchal fold thickness at 12 weeks?

When the baby has reached 12 gestational weeks of pregnancy, the average range for nuchal thickness comes in at 2.18 mm. However, statistics have also revealed that 13% of babies who present with an NT of over 2.5 mm at 12 weeks are born chromosomally normal.

How accurate is the nuchal translucency test?

The nuchal translucency test is considered to be between 70% to 80% accurate. When performed along with an ultrasound and blood tests, the accuracy rises to between 80% to 90%.

The Harmony Test is a more accurate and non-invasive alternative.

When should nuchal translucency be done?

The nuchal translucency test needs to be carried out between gestational weeks 11 to 14, as this is the period when the neck of the baby is still transparent.

What causes Down syndrome during pregnancy?

Trisomy 21 is the more common version of Down’s Syndrome. This is when people have 47 chromosomes er cell, as opposed to 46. Trisomy 21 occurs when nondisjunction takes place – this is an error in how the cells divide.

How can you prevent Down syndrome during pregnancy?

The best way to try to prevent Down’s Syndrome is by planning ahead before conception. Taking 400 mcg (micrograms) of folic acid each day ideally for a few months before conception. Then you need to continue to take in during your early pregnancy.

Nuchal fold scan – how is the risk assessed?

Each woman will be given an estimate of her individual risk for their pregnancy. Your risk is assessed by taking into account the following:

Age of the mother – Amount of fluid behind the neck of the fetus (nuchal translucency).

Fetuses at risk of Down Syndrome tend to have a higher amount of fluid around the neck. Babies accumulate fluid at the back of their neck (nuchal) during the first trimester. As a result of this fluid, the baby’s nuchal fold increases in thickness each day of gestation until the fluid disappears around the 15th week. Researchers have established an average or “normal” thickness for each day during the three weeks you are eligible for the screening If your baby’s nuchal fold is thicker than average, he or she is considered at a higher risk for an abnormality; if it’s thinner, his or her risk is lower.

A more accurate risk assessment combines the Nuchal Translucency scan with the results from two bloods tests that measure the levels of pregnancy-associated plasma protein-A (PAPP-A) and human chorionic gonadotrophin (hCG) in the mother’s blood. Abnormal levels of these two pregnancy-related substances may indicate a problem. Combining the scan and blood test gives a more accurate result than either the ultrasound part or the blood part of the test done on their own.

You must be at least 10 weeks gestation or more for the blood sample to be taken. The Nuchal Translucency scan cannot tell for certain if your baby has a chromosonal defect, however, it can help you decide whether or not the chance of your baby having a chromosonal problem is high enough to warrant having an invasive test such as CVS (Chorionic Villus Sampling) or Amniocentesis. However, these tests carry a slight chance of miscarriage and therefore options should be discussed with their healthcare professional. CVS is performed in the 13th week and amniocentesis around 15th or 16th week of pregnancy.

What Is Amniocentesis?

Amniocentesis is a test usually carried out to examine a baby’s chromosomes, most commonly in search for Down’s Syndrome. Amniocentesis is always voluntary and parents decide if they wish to choose to have this test. The information below may help you to decide whether or not to have this test.

Amniocentesis is the withdrawal of a small amount of fluid from around the baby (amniotic fluid). Cells from the baby’s skin and bladder are in the fluid and can be grown in the laboratory for chromosome analysis. Chromosomes are tiny microscopic packages present in every cell of the body. Normally in each human cell, there are 46 chromosomes. A missing or extra chromosome causes many changes in the way an unborn baby develops. Amniocentesis can detect Down’s Syndrome (which is caused by an extra no.21 chromosome), other chromosome abnormalities and certain genetic conditions when there is a family history of such a disease

How is amniocentesis performed?

Amniocentesis is generally performed from 15 weeks gestation up to the date the baby is due. An ultrasound scan will be done first to check the position of the baby/placenta and to find a pocket of amniotic fluid. The skin on the mother’s abdomen (tummy) is cleaned with antiseptic fluid and a very fine needle is passed through the abdomen and into the womb. A small amount of fluid around the baby (amniotic fluid) is withdrawn. The needle is carefully watched with the ultrasound scan to ensure that it is in the correct position.

The test lasts for 2-3 minutes and afterwards, the baby’s heartbeat is checked. Local anaesthetic is not usually used as the insertion of the anaesthetic is often more uncomfortable than the test itself. Occasionally it may be necessary to pass the needle into the abdomen a second time. If your blood group is Rhesus negative you will require an injection of Anti-D to prevent blood incompatibility developing between you and the baby as a result of the amniocentesis test.

What should I expect after amniocentesis?

For the first few days, you may experience some abdominal discomfort, period-like pain or a little bleeding. These are relatively common and in the vast majority of cases, the pregnancy continues without a problem. You may find it helpful to take some simple pain relief like paracetamol (this is safe in pregnancy) and rest for a few hours.

When can I expect to get the results?

Results of the test are usually available in 2-3 weeks, this is because the cells have to grow before they can be examined. After the amniocentesis arrangements will be made to contact you with the results as soon as they are obtained from the National Genetics Centre Our Lady’s Hospital, Crumlin.

Most people are happy to receive the results over the phone but if you wish to come and obtain the result in person this can be organised. The full result will also tell whether you are expecting a boy or girl – so you may want to give some thought whilst awaiting the result as to whether or not you would like to have this information.

What are the risks associated with amniocentesis?

One in one hundred women who have an amniocentesis test will experience a miscarriage. There are no ways of predicting who will miscarry. For Down’s Syndrome, the amniocentesis result will clearly state whether the baby is affected or not, with a high degree of accuracy (99%).

What happens if an assessment cannot be provided?

On rare occasions, NIPT is unable to provide an assessment of the probability of specific chromosome disorders. This usually reflects the complex biology of genetics and pregnancy, and is not due to a failing in the laboratory.

If NIPT cannot provide a specific assessment, it is not worth repeating the NIPT (unless advised by the laboratory). A decision about other tests (maternal serum screening, detailed ultrasound, amniocentesis or CVS) should be based on the doctor’s assessment of all risk factors identified, and may require specialist consultation.

See Why Have An Early Pregnancy Scan Video With Prof. Shane Higgins


What Our Patients Say

Gráinne Macken

This is my second visit to Merrion Fetal, I was very pleased on both occasions. Lovely quiet waiting room, appointment was on time. The 20-week scan is very detailed we enjoyed watching our baby on the large TV screen. We got some beautiful photos. The nurse was very pleasant and talked us through all the measurements and anatomy. I would highly recommend this scanning clinic.”

Áine Gibney

I had the best experience at the Merrion Fetal Health clinic for my 20-week big scan. The staff were so friendly and so nice and the lovely lady who did my ultrasound scan was amazing. She was so thoroughgoing to absolutely everything and gave me such reassurance on how my baby was growing and developing. I would recommend any Mother to be to attend here if you are looking for a comfortable, reassuring and super pleasant experience.”

Linda O'Sullivan

Highly recommend! We had an early scan due to a little scare at the start of pregnancy and then another at 12 weeks to make sure all was good again. Helen who was scanning on both days was fantastic. We felt totally relaxed and un-rushed while she took her time finding the best angle of baby to get us the clearest pictures as keepsakes all while making sure everything was perfect with baby. She reassured us throughout and I can honestly say it was the best money we ever spent getting both scans done.

Please let Helen know we are 18 weeks now and flying along Highly recommend!



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

Book Your Scan

Screen of Pregnancy Scan

Common Concerns

FAQs - Your Questions


GP Referral Scheme


Health Conditions


Healthy Pregnancy


Medical Studies


Patients' Information


Pregnancy Diary


Pregnancy Magazines

pregnancy health magazines

Scans & Services

18 weeks pregnancy scan facial profile Merrion Fetal Health

Susan's Trimesters

pregnancy trimesters

Videos By Consultants


Midwife sonographer facilitated

Consultant Led, Centre of Medical Excellence 

This page has been checked for accuracy by Dr. Peter McParland in May 2023