Analysis of epidemiological characteristics and associated factors of congenital hypothyroidism in Henan Province

To investigate the epidemiological characteristics and associated risk factors of congenital hypothyroidism (CH) among newborns in Henan Province. A case-control study design was adopted. Children diagnosed with CH from January 1,2016 to December 31,2017 were selected as the cases, and healthy infants with the same sex and birth date less than 30 days old were matched in a 1:1 ratio as the control.Conditional logistic regression was performed to identify factors associated with CH. Subgroup analyses and trend tests were conducted, and restricted cubic spline models were applied to explore the potential nonlinear association between maternal age and CH risk. A total of 843 pairs of children with CH were used in the paired design case-control study.There were 387 male children and 456 female children.In all cases and control pairs, Logistic regression analysis showed that mather’s age[ORadj(95%CI) = 1.26(1.20,1.33),aternal living in the rural [ORadj ( 95%CI) = 1.87(1.15,3.11)], material family history of thyroid diseases[ORadj (95%CI ) = 7.26(2.13,24.75)], exposure to formaldehyde [ORadj(95%CI) = 3.38(1.19,9.58)], material exposure to radiation [(ORadj (95%CI) = 7.07(3.66,21.15)], material medication intake during pregnancy[ORadj(95%CI) = 7.59(3.25,17.72) ], Other feeding methods [ORadj (95%CI) = 3.25(1.67,6.53) ], Progesterone intake during pregnancy [ORadj (95%CI ) = 0.17(0.06,0.43) ], father’s age [ORadj (95%CI) = 1.32(1.24,1.40) ]were statistically significant association with CH, all P<0.05.The results of subgroup analyses were consistent with those listed above.Restricted cubic spline analysis demonstrated a nonlinear dose-response relationship between maternal age and the risk of CH.Specifically, when maternal age exceeded 25 years, there was a positive association between maternal age and CH occurrence in both male and female newborns.Conculsion:Advanced maternal age, rural residence, family history, gestational formaldehyde exposure, radiation exposure, material medication intake during pregnancy, feeding methods, father’s age are factors associated with CH.