Revised Sonographic Scoring Index of Bromley et al for Detection of Down's Syndrome at 14-20 Weeks of Gestation

Parameters:

(1) maternal age in years

(2) major anomaly

(3) thickened nuchal fold (includes cystic hygroma)

(4) short femur for gestational age (ratio of measured to predicted <= 0.91)

(5) short humerus for gestatonal age (ratio of measured to predicted < 0.90)

(6) pyelectasis of the renal pelvis (anterior to posterior diameter >= 4 mm)

(7) hyperechoic bowel (as bright as bone)

(8) echogenic intracardiac focus

where:

• The predicted femoral length was (0.9028 * (bipareietal diameter)) - 9.3105

• The predicted humeral length was (0.8492 * (bipareietal diameter)) - 7.9404

• The revised scored removed evaluation for choroidal plexus cysts because new data shows a lack of correlation with Down's syndrome.

total score =

= SUM(points for all 8 parameters)

Interpretation:

• minimum score: 0

• maximum score: 11

• The higher the score the greater the risk of the fetus having Down's syndrome.

• A score >= 2 identified 76% of fetuses with Down's syndrome with a false positive rate of 6% (prevalence of Down's syndrome in study 23%, with 53 Down's and 177 normal controls).