Dublin, Dublin (prsafe) March 15, 2012 - The centre of excellence, consultant led ultrasound pregnancy scan clinic, Merrion Fetal Health, explains in layman's language about early pregnancy scans and other ultrasound pregnancy scans.

What is an ultrasound?

Ultrasound uses high frequency sound waves, which cannot be heard by the human ear, to produce images of the pregnancy. The sound waves are emitted from a transducer using a lubricating gel to facilitate the scan.

There are two types of scans: an abdominal scan and a transvaginal scan. An abdominal scan is performed by placing the transducer onto the abdomen of the patient. The process of an abdominal scan is non invasive and painless. Normally, you will be required to have a full bladder for an abdominal scan in early pregnancy. The bladder is used as an acoustic window to improve the image quality and it also improves the position of the baby.

In the early gestational period the sonographer will have to perform a transvaginal scan (TVS) to be able to assess the pregnancy. A transvaginal ultrasound 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 with a TVS the procedure will be discussed with you and your permission sought. Like an abdominal ultrasound a TVS is not painful but may be a little uncomfortable and possibly a little embarrassing.

Ultrasound is used to obtain valuable information about your pregnancy and has been routinely used in pregnancy for over 35 years and there is no evidence to date to suggest that it is harmful to baby.

EARLY PREGNANCY SCANS

A scan can be performed at any stage during a pregnancy. Many patients have an early pregnancy scan for reassurance and just to know that all is well with the pregnancy and for many it is the first positive confirmation that they will become a parent. In early pregnancy a scan may be indicated if there is any bleeding or pain or a history of previous pregnancy problems. An early pregnancy scan is sometimes referred to as a viability scan or a dating scan.

Early Pregnancy Scans are performed to:

- confirm the presence of the baby's heartbeat

- calculate the gestational age

- determine the estimated date of delivery (EDD)

- look for multiples

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. Normally, if it is not possible to confirm whether your pregnancy is ongoing or not you will be rescanned in 7 - 10 days time.

Nuchal Translucency Test/Nuchal Scan

Also in early pregnancy between weeks 11-14, a Nuchal Translucency or First Trimester Screen can be performed.

This scan is performed to:

- screen for Down's Syndrome and other abnormalities (the measurement of the fluid at the back of the baby's neck can be an indication of a fetal abnormality or syndrome).

- confirm the presence of certain vital parts of the anatomy such as the baby's skull, brain, nasal bone, spine, heart, stomach, abdominal wall, kidneys, bladder, arms & legs.

A blood sample is also requested to help identify any abnormalities. This is more accurate than either the ultrasound part or the blood part of the test done on their own, without the backup of the other test. A nuchal translucency test cannot tell for certain if your baby has a chromosomal defect. However, it can help you decide whether the chances of your baby having a chromosomal problem is high enough to warrant having an invasive test, such as CVS or amniocentesis.

Anatomy Scan - 18-22 Weeks Gestation:

An anatomy scan is often referred to as "the twenty week scan" or "the routine scan". It is normally performed between 18 - 22 weeks gestation as this is the best opportunity during pregnancy to examine all the anatomy of your baby in great detail. During this scan a full anatomical survey of the baby will be carried out. The placenta will be localized and measurements of your baby will be taken to ensure that he/she is growing normally. Gender can also be determined at this stage, however, it is not always possible to determine the gender of the baby due to the presentation or lie of the baby.

The majority of babies are healthy at birth, but unfortunately about 2-3% of babies are born with a birth defect. About half of these major defects will be seen on scan and half will not be detected during pregnancy. This means that even if your scan is apparently normal there is a small chance that your baby may still have a problem because ultrasound has its limitations.

To see a table which highlights the different potential birth defects, many of which can be seen to some extent during the anatomy scan, click on ultrasound scan Dublin.

Growth & Wellbeing - 24 Gestational Weeks Onwards:

Later in pregnancy your obstetrician may request a growth & wellbeing scan. This is normally performed from 24 weeks onwards and is performed to evaluate the pregnancy:

The purpose of this scan is:

- to determine the lie & presentation of the baby (breech or cephalic)

- to estimate fetal weight

- to determine the location of the placenta

- to measure the fluid around the baby

- to measure the blood flow in the baby's umbilical artery

- to evaluate the pregnancy for abnormalities

- to determine gender (from 19 weeks gestation ).

Contact:

Claire Broughan

Address:

Merrion Fetal Health

2nd Floor

60 Lower Mount Street

Dublin 2

Tel:

+353 1 663 5060

Fax:

+353 1 663 5061

Email:

claire@merrionfetalhealth.ie

Website:

http://www.merrionfetalhealth.ie/

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