Congenital Hypothyroidism and its Related Factors in an Iranian Population: A Retrospective Study in Semnan (2011-2016).

Abstract

Background:Congenital hypothyroidism (CH) is an important and preventable cause of intellectual disability. This study determined the incidence of CH and its related factors in Semnan city in Iran.Methods:All neonates born in Semnan from 2011 to 2016 who participated in a screening program for CH were evaluated to estimate the incidence of CH. In a nested case-control study, all diagnosed CH cases were compared with a control group of healthy newborns. Statistical analysis used conditional logistic regression model with STATA-14.Results:106 out of 17,507 neonates born in Semnan during 2011–2016 were diagnosed with CH (6.05 cases per 1,000 live births). Maternal parity (odds ratio [OR] =1.78, P = 0.044), birth weight (OR = 0.29, P = 0.001), parental history of thyroid disease (OR = 3.43, P = 0.001), father's education (OR = 0.71, P = 0.003), father's occupation (nonworker) (OR = 2.97, P = 0.001), and the presence of other anomalies (OR = 4.14, P = 0.037) were related to the incidence of CH.Conclusions:The cumulative incidence of CH in Semnan was higher than in both the global and national statistics. Aside from well-known medical determinants, some important social factors such as father's occupation and education have a significant and independent relationship with occurrence of CH; rational attention should be given to them in health care programs to increase the effectiveness of preventative measures for CH.