What is an Ultrasound scan?

Diagnostic ultrasound has been used for many years in clinical medicine with no proven side effects.
Ultrasound uses high frequency sound waves which cannot be heard by the human ear and produce a picture of the womb, the baby and the placenta
(afterbirth). It is used by midwives and doctors to gain valuable information about the pregnancy.

Should all pregnant women have a scan?

It is our policy here in University Hospital Galway to offer 2 scans:
1 – A dating scan in the first trimester (up to 13 weeks + 6 days). This is normally carried out in the maternity scan room but in some cases you may have it performed in the Early Pregnancy Assessment Unit.
2 – Anomaly scan at 20-23 weeks gestation.
Please telephone the Maternity Scan Room at 091 544537 to arrange your appointment.

What are the reasons for having a scan performed?

There are many valid reasons for having a scan during your pregnancy and your midwife or your doctor will best advise you if one is necessary.

The following is a list of possible reasons for having an ultrasound scan.

To establish the expected date of delivery.

  • The development and growth of your baby during pregnancy.
  • The presence of virtually all twins, triplets.
  • The position of the baby at any given time.
  • Demonstrate the baby’s heart beat.
  • Determine the position of the placenta.

Bleeding or pain in early pregnancy.
Ultrasound has the ability to diagnose a miscarriage, or ectopic pregnancy. Occasionally a vaginal scan may be suggested as it can generally yield more information about the very early stages of pregnancy. The procedure will be explained in detail beforehand.
If you ask we will check the sex of the baby at the end of the scan but you must be aware that we cannot always see it due to the position of the baby and that we are not always right.
If we cannot see it then we do not rescan for sexing of babies as this is not part of the scan.

Will a scan detect all abnormalities of the baby?

No. –
”Women should be informed of limitation of routine US screening and that detection rates may vary by the type of fetal anomaly, the woman’s body mass index (BMI) and the position of the unborn baby”.
(Nice Guidelines – Antenatal care – Issued March 2008. Routine care for the healthy pregnant woman)

The ultrasound scan is very accurate but unfortunately it cannot diagnose 100% of congenital abnormalities. We would expect to pick up at least 90% of cases of open spina bifida, 75% of cases of cleft lip and 50% of cases of serious cardiac anomaly.
(NSUCoRG draft US standards March 2009).

Because 30% to 50% of cases of Down’s syndrome appear normal on ultrasound the only way to diagnose or exclude a chromosomal problem for certain is to have an amniocentesis. (RCOG 2000).
It is also important to realise that ultrasound scans in pregnancy do not detect problems like cerebral palsy or autism.
Occasionally however an abnormality of the baby will be noted during the scan. If this situation arises you will be informed at the time and a detailed scan will be offered and organised as soon as possible with one of our Fetal Medicine Consultants.

Do I need a full bladder for the scan?

Yes. A full bladder is necessary for your scan.

Can my Partner attend the ultrasound?

Yes, your partner or one other person is welcome to attend the ultrasound with you.
Please do not bring children, children are not allowed into the Ultrasound Scan Room.

Can I have a photograph of the baby?

Yes, you may certainly have a scan picture, but as the roll of film is very expensive, and it is our policy not to charge for photographs, only one or two photographs are given to each woman or couple during the pregnancy.

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