In a large no. of patients bilaterally oophorectomized early in pregnancy, no careful attempt has been made to investigate the excretion of oestrone and prolan; only 4 such cases are known to have been studied hitherto. In a case of bilateral oophorectomy ca. 3 mos. after conception, in which the authors studied the urinary oestrone and prolan output, pregnancy, delivery and child were normal. (The child was not breast fed.) The urinary excretion of the anterior lobe hormone was not diminished during pregnancy but the excretion of oestrone diminished.