Guidance for the
professional
Some pregnancies affected by aneuploidy will have sonographic markers, which
are listed below, but many normal pregnancies will also have these features.
If you are scanning at 20 weeks it is very important
to know what screening has already been undertaken
in your population. If your population has already
been screened using maternal age alone, or in
combination with nuchal translucency measurement
or serum screening, 50-80% of affected cases
will already have been identified, and it is
therefore much less likely that a sonographic
marker will be linked to aneuploidy, most typically
trisomy 21, than in an unscreened population.
Ultrasound Checklist
- Sonographic "markers" for aneuploidy Other
risk factors
- Choroid plexus cyst Maternal age (> 35
yrs)
- Ventriculomegaly (> 10 mm at the atrium)
Serum screening results
- Echogenic bowel (equivalent to bone density)
Nuchal translucency (10-14 week scan)
- Head shape
- Nuchal pad (> 5 mm at 20 weeks)
- Cysterna magna
- Cleft lip
- Echogenic foci in heart
- Dilated renal pelvis (> 5 mm AP)
- Short femur/humerus
- Talipes
- Sandal gap
- Clinodactyly
- Clenched hand
- Two vessel cord
