BACKGROUND: The incidence of Down syndrome (DS) in Egypt varies between 1:555 
and 1:770 and its screening by triple test is becoming increasingly popular 
nowadays. Results, however, seem inaccurate due to the lack of Egyptian-specific 
information needed for risk calculation and a clear policy for programme 
implementation. Our study aimed at calculation and validation of the triple 
marker medians used in screening Egyptian females as well as to recommend 
programme conventions to unify screening in this country.
METHODS: The study was conducted on 668 Egyptian women, in weeks 15-20 of 
pregnancy as proven by sonar. Chorionic gonadotropin (CG), α-fetoprotein (AFP) 
and unconjugated oestriol (uE3) were measured on Siemens Immulite analyzer. 
Medians of the three parameters were calculated, regressed against gestational 
age (GA) and weighted by the number of participants/week. Equations were derived 
to adjust each parameter to the maternal weight and were centered on the median 
Egyptian weight. Prisca software was fed with the above data, 
multiples-of-median (MoM) and DS risks were calculated and the screening 
performance was evaluated at a mid-trimester risk cutoff of 1:270.
RESULTS: Log-linear [AFP/uE3 = 10(A+B*GA)] and exponential equations [CG = A*e 
(B*GA)] were derived and the regressed medians were found to follow similar 
patterns to other Asian and Western medians. Oestriol was always lowest (even 
halved) while CG and AFP were intermediate. A linear reciprocal model best 
fitted weight distribution among Egyptians and successfully adjusted each 
parameter to a weight of 78.2 kg. Epidemiological monitoring of these 
recommendations revealed satisfactory performance in terms of 6.7% initial 
positive rate and 1.00 grand MoM.
CONCLUSIONS: Adoption of the above recommendations is hoped to pave the way to a 
successful DS screening programme tailored to Egyptian peculiarities.