title: Birth prevalence of congenital hypothyroidism in Mexico.
abstract: The Mexican Institute of Social Security (IMSS) provides care for more than 40% of the Mexican population. This report constitutes the first study of the incidence of congenital hypothyroidism (CH) in Mexican children. We performed a prospective study with a population base. CH screening began in 1997 with blood samples from the heel taken 72 h after birth; from 2000, the detection strategy was changed nationwide and blood samples were taken from the umbilical cord in all newborns for determination of thyroid-stimulating hormone (TSH) concentration. We evaluated the annual coverage. TSH concentration was measured by chemoluminescence; TSH values > or =30 microIU/mL in umbilical cord blood and 15 microIU/mL in capillary blood were considered positive cases and were confirmed through hormonal studies. The incidence and 95% confidence intervals [95% CI] were calculated. We found that coverage within the IMSS population was 53% from 1997 to 2000 and had increased to 95% by 2001. A total of 2,777,292 children from 2,975,157 births (93%) were studied between 2000 and 2004. Of these, 4050 had a high TSH concentration leading to suspicion of CH; CH was confirmed in 1286 (32%). The resulting incidence was 4.3/10,000 livebirths [95% CI 3.6, 5.1]. With the results obtained, we conclude that the IMSS strategy of CH screening at birth ensured 95% coverage of children in the system. The birth prevalence of CH reported is among the highest in the world.
authors.affiliation: Unidad de Salud Pública, Coordinación de Programas Integrados de Salud, Hospital de Pediatría Centro Médico Nacional, Siglo XXI, México.
authors.forename: Mario E
authors.initials: ME
authors.lastname: Rendón-Macías
authors.forename: Inés
authors.initials: I
authors.lastname: Morales-García
authors.forename: Emilio
authors.initials: E
authors.lastname: Huerta-Hernández
authors.forename: Anabel
authors.initials: A
authors.lastname: Silva-Batalla
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Villasís-Keever
mesh_terms: D003409:Congenital Hypothyroidism / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007231:Infant, Newborn; D008800:Mexico / Q000453:epidemiology; D015997:Neonatal Screening / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013223:Statistics as Topic; D013972:Thyrotropin / Q000032:analysis* / Q000097:blood
chemical_list: D013972:Thyrotropin