Certificates of competence
The 11-13 weeks scan
Importance of the 11-13 weeks scan
The 11-13 weeks scan provides the most effective method of early screening for trisomy 21 and other major chromosomal abnormalities. Screening by nuchal translucency can detect about 80% of affected fetuses for a false positive rate of 5%. The combination of nuchal translucency and maternal serum free β-hCG and PAPP-A improves the detection to 90%. There is now evidence that the detection rate can increase to about 95% and the false positive rate can be reduced to 2.5% by also examining the nasal bone, facial angle, ductus venosus flow and tricuspid flow. This method of screening is superior to the alternative methods of maternal age or maternal serum biochemistry at 15-20 weeks because the respective detection rates are about 30% and 55-70% for a false positive rate of 5%.
Other benefits of the 11-13 weeks scan include: accurate dating of the pregnancy, early diagnosis of many major fetal defects, diagnosis of multiple pregnancies and early screening for severe preeclampsia.
Implementation of the 11-13 weeks scan
The Fetal Medicine Foundation (FMF) has introduced a process of comprehensive training, support and audit for the proper implementation of the 11-13 weeks scan. The FMF advocates that effective screening for abnormalities and preeclampsia requires:
1. Carrying out the ultrasound examination by appropriately trained sonographers - see FMF Certificates of competence in:
- Measurement of nuchal translucency
- Assessment of the nasal bone
- Measurement of the facial angle
- Assessment of ductus venosus flow
- Assessment of tricuspid flow
- Measurement of uterine artery PI
2. Measurement of maternal serum free β-hCG and PAPP-A by laboratories that can demonstrate good quality assurance performance - see Registered Laboratories.
3. A risk calculation program that uses an algorithm based on scientific evidence (see at the end of this page).
4. Appropriate counselling of the parents.
Registered software companies
Astraia Software GmbH
Contact: Roland Denk
Tel: +49 89 127 1147 0
Fax: +49 89 127 1147 17
Email: info@astraia.com
Web address: www.astraia.com
ViewPoint
Contact (Germany): Gaby Rosenauer
Tel: +49 8153 93110
Fax: +49 8153 931130
Email: vpinfo@med.ge.com
or enquiries@diagnosticultrasound.org.uk
Web address: www.gehealthcare.com/viewpoint
Contact (UK): Jeff Mallchok
Tel: 0044 (0)1483 815120
Fax: 0044 (0)1483 815121
Email: sales@hncl.net
Internet course on the 11-13 weeks scan
Covers all aspects of the 11-13 weeks scan.
Compulsory for FMF Certificates of competence
- Measurement of nuchal translucency
- Assessment of the nasal bone
- Measurement of the facial angle
- Assessment of ductus venosus flow
- Assessment of tricuspid flow
- Measurement of uterine artery PI
Available in 20 languages.
Free of charge
To view the list of health care professionals and others who have attended the internet based course on the 11-13 weeks scan please click here.