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Antenatal Screening & Diagnosis

Screening information

All tests offered are free and is your choice if you wish to be tested.

You should have received the NHS 'screening tests for you and your baby' leaflet either by post or from your community midwife, which should assist you in deciding.

You can also download this booklet which includes a link to translations into 17 languages.

Your midwife or GP will explain each test to you and will be able to answer any questions you may have.

For more information about antenatal screening click here.

What tests do we offer at Colchester?

At your booking appointment (usually when you are between 8-12 weeks pregnant) we can take a blood sample to check the following:

At this appointment you will also be asked for a urine sample to check for protein and infection.

Another blood sample will be taken at 28 weeks gestation to check iron levels and antibodies again.

Your tests results will normally be given to you at your next antenatal appointment.

Ultrasound scans

We offer two ultrasounds scans as standard - Booking/Dating scan (between 11-14 weeks). At this scan, we will measure the baby's size and based on this we will estimate your baby's due date (EDD), that the baby is doing well and whether you are carrying more than one baby. It is helpful if you can have a full bladder for this scan.

Testing for Down's syndrome (Combined test). This test is optional and will provide a statistical risk of whether your baby is more or less likely to have Down's syndrome or some other chromosomal abnormalities. At your dating scan, we can measure the amount of fluid behind your baby's neck (the nuchal translucency or NT). We also take a blood test for two hormones in your circulation. These are combined to give a risk - the combined test will not tell you for certain if your baby has Down's syndrome or not, but gives an indication of the risk or probability of Down's syndrome. If your risk result is greater than 1:150, you will be offered further tests which can give a definite diagnosis.

Please note, we do not offer the option of an invasive test such as chorionic villus sampling or amniocentesis based on maternal age alone - these tests are only offered to women who have had a previously affected pregnancy or whose test result is in the greater risk category of higher than 1:150.

Quad Test. If it is not possible to measure the NT behind the baby's neck, for example due to the baby lying in the wrong position during the scan, or if your pregnancy when dated is greater than 14 weeks and 2 days but less than 20 weeks, we offer the quad test as an alternative to the combined test.

This test measures three hormones and a protein level in the maternal circulation and like the combined test, will give a greater or lesser chance as to whether your baby has Down's syndrome, with the same opportunity to consider an invasive test if the risk is greater than 1:150. The quad test is slightly less accurate than the combined test.

Anomaly scan: Usually performed between 18-21 weeks. At this scan, we check the baby for any abnormalities or health problems and also check the position of the placenta. About half of the major abnormalities which cause serious difficulties will be seen on scan and around half will not be seen, which means that even if your scan is normal, there is a small chance that your baby may have a problem.

It may also be possible to see the gender of the baby at this scan, although we cannot guarantee a correct diagnosis of the baby's sex. Please tell the sonographer at the start of your appointment if you would like to know if the baby is a boy or a girl.

You can contact the Antenatal Screening midwives on the following number: 01206 746563

For Ultrasound Scan enquiries please call 01206 742502.