ABSTRACT As pregnant women are susceptible to changes in iodine, which can cause miscarriage, goiter, thyroid nodules, hypothyroidism, in addition to fetal neurological impairment or development. The aim of this study was to verify the implications of the iodine alteration in each gestational trimester and its consequences of physiological justification. The review was based on PRISMA. Searching for articles that took place in March 2020 without delimiting data. As bases consulted were the Clinical Trials, Cochrane Library, Lilacs and Medline (PubMed).

The descriptors were combined as follows:

"pregnancy" AND "iodine deficiency". Articles that addressed iodine deficiency and its implications were included. The selection followed the steps of reading the titles, abstracts and full articles. To assess the methodological quality of the studies, the STROBE Instruction instrument was used. The research resulted in 1,266 studies and 11 were included. In assessing methodological quality, the lowest score was and the maximum 20. According to studies, the fourth most affected by iodine loss are the second and third, it is possible to increase the volume and pneumatic nodules, subclinical hypothyroidism, pre-eclampsia, among others. The damages caused by iodine deficiency in the first or second trimester are still reversible, therefore, they need to be diagnosed early, to guarantee an iodic homeostasis and prevent damage to the health of the mother-child binomial.