RESUMO
Although Hispanics of Mexican origin in the United States have been identified as a population with a particularly higher rate of Down syndrome (DS), there is a paucity of studies concerning this topic in Mexico. The aim of this study was to determine the prevalence and risk factors for DS in a population from Western Mexico. For prevalence, 230 liveborn infants with DS were included from a total of 89,332 births occurring during the period 2009-2017 at the Dr. Juan I. Menchaca Civil Hospital of Guadalajara (Mexico). In order to evaluate potential DS risks, a case-control study was conducted among 633 newborns, including those 211 DS patients with full trisomy 21 (cases) and 422 infants without birth defects (controls). Data were analyzed using multivariable logistic regression analysis. The overall prevalence for DS was 25.7 per 10,000 (95% confidence interval [95% CI]: 22.4-29.1). Patients with DS had a significantly higher risk for family history of DS in distant relatives (adjusted odds ratio [aOR] = 4.4, 95% CI: 2.5-7.7), relatives with thyroid disease (aOR = 2.3, 95% CI: 1.2-4.0), maternal age ≤ 19 years (aOR = 5.1, 95% CI: 2.7-9.6) or ≥ 35 years (aOR = 3.3, 95% CI: 1.5-6.9), paternal age ≤ 19 years (aOR = 3.5, 95% CI: 1.7-7.4), pre-pregnancy BMI ≥ 25 kg/m2 (aOR = 1.6, 95% CI: 1.0-2.4), and pre-pregnancy alcohol consumption (aOR = 1.8, 95% CI: 1.1-2.9). The identified risks in family history, and previously mentioned nutritional disadvantages were associated with DS in our sample and probably also to its increased prevalence in our population.