Introduction:

Family history of thyroid disease (FHTD) as risk factor for congenital hypothyroidism (CH) in patients with Down syndrome (DS) has not yet been explored.

Objective:

To determine whether FHTD is associated with an increased risk for CH in DS.

Method:

Case-control study in 220 neonates with DS. Thyroid function tests of 37 infants with DS and FHTD (cases) were compared with those of 183 DS newborns without FHTD (reference group). Data were analyzed using multivariate logistic regression analysis and adjusted odds ratios (aORs) with their respective 95 % confidence intervals (CI) were calculated.

Results:

Nine newborns with DS in our sample had CH (4.1 %). FHTD showed an association with CH in neonates with DS (aOR = 8.3, 95 % CI: 2.0-34.3), particularly in males (aOR = 9.0, 95 % CI: 1.6-49.6). In contrast, newborns with DS without FHTD were less likely to suffer from CH (aOR = 0.4, 95 % CI: 0.1-0.8).

Conclusions:

FHTD detailed evaluation can be an easy and accessible strategy to identify those newborns with DS at higher risk for CH.