MYXEDEMA in women is usually associated with altered menstrual function, infertility, or repeated abortion.1 Parkin and Greene 2 described the occurrence of pregnancy in one patient with cretinism, in two with juvenile myxedema, and in three with adult myxedema. Their review of the world's literature revealed 10 previously recorded cases of pregnancy in true hypothyroidism, making a total of 16 cases.3 Their methods of diagnosis included determinations of the basal metabolic rate and the serum cholesterol, the clinical appearance, and the response of the patient to thyroid extract. Myxedema cannot always be diagnosed unequivocally by clinical findings plus these laboratory aids. In the past, many, varied disorders of the female reproductive function unfortunately have been attributed to hypothyroidism on the basis of a single basal metabolic rate determination. We agree that the 16 previously reported cases represented true myxedema. One might expect that the increased accuracy of diagnosis made possible by determinations of protein-bound iodine of the blood plasma and radioactive-iodine-uptake studies would lead to recognition of a greater number of women with myxedema in whom pregnancy had occurred without thyroid therapy. No additional cases have been reported since Parkin and Greene's summary in 1943.The purpose of this paper is to report a pregnancy in an unequivocally myxedematous woman whose symptoms were established and had persisted for a 15year period, during which time she bore six children, four of whom are living today. During this time she had never taken thyroid substance. Studies of the mother and her four children comprise the present report.