Also by measuring the levels of AFP, Estriol and HCG it is possible to estimate the risk of your baby being born with a chromosomal abnormality such as Down’s Syndrome.

Occasionally the test results are inconclusive, and we may ask you to have the test repeated. Do not worry about this since most tests would then fall within the normal range.

It is important to remember that a screening test only gives us an indication of the risks. The majority of women will have perfectly normal results. If the AFP/HCG/E3 levels are abnormal in any way, further more decisive tests such as a detailed ultrasound scan or amniocentesis may be suggested. If an abnormality of any kind is found following these further tests you may need to consider a termination of the pregnancy. You might wish to discuss such possibilities with your partner before deciding to have the antenatal screening tests.

A Normal Result
Most pregnancies will have a normal test result and a report will be conveyed to you. If you have not heard from the doctor within about 10 days you may assume the test is normal.

The test cannot identify every abnormality and a normal AFP/HCG/E3 result is not a guarantee that your baby will be healthy. However, if your test result is normal, it will reduce the chance of an abnormality being present.

A High Afp Result
This may indicate that the baby is at risk of having a defect such as Spina Bifida.

If your result is high you will be advised to have a detailed ultrasound scan. Following the scan you will have the opportunity to discuss the significance of the raised AFP and should any abnormality be found, this would be fully discussed with you at the time. About 9 out of 10 of Spina Bifida babies will be detected by a raised AFP.

If the AFP level is raised and no abnormally has been found, you will receive extra antenatal care, because it has been shown that there may be a slightly increased risk of these babies being smaller than average.

The Afp/Hcg/E3 Result (Triple Test)
By measuring the AFP/HCG/E3 levels, and considering your age and stage of pregnancy, it is possible to estimate the risk of your baby being born with a chromosomal abnormally such as Down’s Syndrome. Risk is often quoted in terms such as 1 in 280 or 1:280. What this means is that out of 280 pregnancies, then 1 of them will be affected and 279 will be normal.

If your risk is shown to be more than 1 in 400 of having a baby affected by Down’s Syndrome (for example 1 in 50), you will be set an appointment to discuss this. After discussion you may choose to have an amniocentesis which will confirm whether or not the baby is affected. Most women will have a normal amniocentesis result, but if an abnormality of any kind is found it will be fully explained to you and you will have ample time to discuss this.

Overall, about 6 out of 140 Down’s Syndrome babies will be detected by the Triple test. The rate of detection has been shown to vary according to the age of pregnant mother as shown.