For that one, I think I found a later publication of it (or perhaps just a better citation):

• "Iodine deficiency and the maternal/fetal relationship". In: Dunn JG, Medeiros-Neto GA, eds. Endemic goiter and cretinism: continuing threats to world health. Washington, DC: PAHO, 1974. (Scientific publication 292).

The book/report shows up in Worldcat in ~10 institutions, so ILL should get it.

Also good would be these 2 chapters:

• Pretell EA, Caceres A. "Impairment of mental development by iodine deficiency and its correction. A retrospective view of studies in Peru". In: Stanbury JB, ed. The damaged brain of iodine deficiency. New York, NY: Cognizant Communication, 1994:187–91
• Greene LS. "A retrospective view of iodine deficiency, brain development and behavior from studies in Ecuador". In: Stanbury JB, ed. The damaged brain of iodine deficiency. New York, NY: CognizantCommunication1994:173–85