Nuchal Scans

The vast majority of babies are born normal. However, all ladies have a risk of having a baby with a chromosome abnormality such as Downs Syndrome.

The only way to know for certain if your baby has a chromosomal abnormality is by having an invasive test such as Chorion Villus Sampling (CVS) or Amniocentesis. However, these tests carry a 1% risk of miscarriage.

An invasive test is therefore usually offered only if the risk of Downs Syndrome is 1 in 300 or above.

The most accurate way of estimating the risk of your baby having Downs Syndrome is to perform a NUCHAL ULTRASOUND SCAN in conjunction with a simple blood test from the mother between 11wks and 13 weeks 5days of pregnancy.

The risk of your baby having Downs Syndrome depends upon:

The age of the mother
The amount of fluid behind the baby's neck (the nuchal translucency)
The level of two hormones in the mother's blood (BhCG & PAPP-A)

Once all this information is gathered, the estimated risk for Downs Syndrome can be established.

The results will be available on the same day unless you have an evening appointment when the results are usually available by midday the following day.

The results will be discussed with you and then you can decide if you wish to have an invasive test.

The nuchal scan is an important scan for various reasons:

To date the pregnancy accurately if you have not had an early pregnancy scan and are uncertain as to the date of your last menstrual period, have an irregular cycle, have conceived whilst breastfeeding or have conceived soon after stopping the pill.
To assess the risk of Downs Syndrome and other chromosome abnormalities.
To diagnose multiple pregnancies. If you have not already had an early dating scan, a multiple pregnancy can be diagnosed.
To exclude any major fetal abnormalities. Major fetal abnormalities are often visible by 12 weeks of pregnancy, although a 20 weeks scan is also advisable, particularly for looking at the fetal heart in greater detail.
To diagnose a miscarriage. Sadly, in approximately 3% of ladies who attend for a nuchal scan, it is discovered that the baby has died several weeks beforehand, without the woman having any pain or bleeding. Our Consultant Obstetrician is always available in such cases to discuss the reasons behind miscarriage and to discuss the options for further management.