The precipitable iodine of serum in normal pregnancy and its relation to abortions

son and Man (1) that early in pregnancy the pre-cipitable (protein-bound) iodine in the serum (SPI) rose to concentrations in the upper range of normal or even to levels that outside of preg-nancy are characteristic of hyperthyroidism. It also appeared that if the SPI did not rise, the pregnancy was likely to end in abortion within the first four months. Some evidence was presented that such accidents might be prevented by the ad-ministration of active thyroid substance. The present paper deals with a further investigation of the phenomenon. MATERIA