Background: The most studied risk factors for Down Syndrom (DS) were: region of residence, exposure to chemicals, parents' education level, cigarette and alcohol use by father or mother or both, and oral contraceptive (OC) use.
Objective: The aim of this study was to compare certain variables considered as risk factors on DS such as parental age at birth, OC use, child's sex, and rank of birth between children with DS and their siblings without DS as well as to determine the socio-bio-demographic characteristics of the families studied compared with the general Moroccan population.
Material and methods: We conducted a cross-sectional analysis of 277 families with 925 siblings and at least one child with DS (279 with DS) between 2014 and 2017. The data are collected using a standardized questionnaire in MarrakechSafi region. Data were entered and analyzed using the statistical program SPSS statistics software for Windows (version 20.0). Chi-square (χ2) and Student t tests were used for testing statistical significance. Differences were considered significant when the p-value <0.05.
Results: The binary logistic regression analysis between DS and non-DS children in their bio-demographic characteristics studied (sex, maternal age at birth, paternal age at birth, oral contraceptive (OC) use, length of oral contraceptive use before pregnancy and rank of birth) showed that only maternal age and paternal age at birth and OC use were associated with DS birth (OR= 1.16; 95% CL: 1.11-1.21, OR= 1.05; 95%CL: 1.01-1.09 and OR= 0.01; 95%CL: 0.00-0.003, respectively). In the other hand, the comparison between socio and bio-demographic characteristics of households studied with data from National Population Survey and Family health (2018) showed a higher level of education in women and men in our sample. Similar results were shown in rate of men and women in paid employment, the rate of smoking and alcohol consumption among men and the rate of OC use before pregnancy among women.
Conclusion: These results will help to sensitize the Moroccan population about risk factors for DS.
Keywords: Down syndrome; Morocco; children; maternal age; oral contraceptive; paternal age; socio-bio-demographic factors.
National Institute of Public Health NIH - National Research Institute.