Protein-bound iodine in premature infants.

The normal pregnant woman and the newborn infant both have raised hormonal iodine levels (Rose, Russell, and Starr, 1963; Pickering et al., 1958). The very early fetus has a low hormonal iodine which rises as gestation proceeds, but the level in premature babies is still lower than that of full-term infants (Andreoli and Robbins, 1962; Rose et al., 1963; Marks and Man, 1965). The serum protein-bound iodine (PBI) levels in the full-term newborn infants rise to a peak at about 48 hours (Perry, Hodgman, and Starr, 1965; Danowski et al., 1951) and then tail off slowly. The levels in the premature baby also rise to a maximum at 48 hours (Perry et al., 1965) and drop over the next 8 days, but there is scant information about levels of the premature infant at birth and through the early weeks of life.