This application allows estimation of risks for trisomies 21, 18 and 13 at 11-13 weeks’ gestation by a combination of maternal age, fetal nuchal translucency thickness, fetal heart rate and maternal serum free ß-hCG and PAPP-A. At a risk cut-off of 1 in 100 the detection rate is 90% for trisomy 21 and 95% for trisomies 18 and 13, at false positive rate of 4%.

It is strongly recommended that those undertaking assessment of risk receive the Fetal Medicine Foundation Certificate of competence in the 11-13 weeks scan. MoM values for PAPP-A and free ß-hCG depend on maternal characteristics but also on the equipment and reagents used at a specific laboratory; you will therefore need to obtain the MoM values from your laboratory.

Please record the following information and then press Calculate.

Maternal characteristics


Pregnancy findings


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