Diéguez M, et al. - From April 2010 to March 2011, researchers conducted a cross-sectional study in a referral centre in collaboration with the primary care units to evaluate the prevalence of thyroid dysfunction (TD) during pregnancy and to examine the association with maternal age. For this investigation, they involved 2509 consecutive pregnant women living in an iodine-sufficient area, mean age 32 years (range 16–47) who were universally screened for TD in their first trimester. During the first antenatal visit, thyroid-stimulating hormone (TSH) and free T4 (FT4) were analyzed. Four hundred sixteen women with positive TD screening were identified in this investigation. In an iodine-sufficient population, TD affects one in six pregnant women. They found that maternal age ≥30 years did not increase the risk of TD.