The concentration of radioiodine by the foetal thyroid gland and its relation to congenital goitre in sheep

Summary The ability of the foetal sheep thyroid to accumulate radioiodine varies markedly during gestation. From sixty to one hundred days of foetal age the foetal and maternal glands are similar in this respect but from one hundred to a hundred and twenty days the foetal capacity increases until it is four times greater than the maternal and continues at this level until parturition. The ingestion of kale by the ewe is more effective in producing congenital goitre during the fourth month of pregnancy than it is at other times. This corresponds to the period during which the foetal gland is developing its high power of absorption of iodine.