1st April 2022

A 36-year-old woman presents for an ultrasound scan at 11 weeks gestation

A 36-year-old woman presents for an NHS ultrasound scan at 11 weeks gestation. This is her first pregnancy, and so far, it has been uncomplicated. On the ultrasound, the nuchal translucency is 4 mm. Her blood test results show a low PAPP-A. She is informed there is a high likelihood that the foetus may have trisomy 21 (Down’s syndrome).

Which is the most appropriate investigation to diagnose trisomy 21 in the foetus?

Select the SINGLE most appropriate option from the list below. Select ONE option only.