Physiological State of Thyroid of Mother and Fetus. 185 



117 (813) 



The correlation between the physiological state of the thyroid of 

 the mother and of the fetus. 



(Preliminary note.) 



By A. J. Carlson. 



[From the Hull Physiological Laboratory of the University of 



Chicago.} 



The starting point of this investigation was some observations 

 (incidental to other work on the thyroids) that pups born of 

 mothers having active hyperplasia of the thyroids seemed to have 

 much larger thyroids than the pups born of mothers with normal 

 thyroids or with colloid goiters. The size of the thyroid in pups 

 from mothers with marked thyroid hyperplasia is in many cases 

 so great that they produce the distortion of the neck similar to 

 goiter in adults. These pups are apparently born with goiter. 



The work was begun in the spring of 1912, and so far data have 

 been obtained on mother and offsprings in the case of 16 cats and 

 14 dogs ; the work is being continued and extended to other species. 



It is well known that goiter (active hyperplasia and colloid) 

 is prevalent in dogs in the Great Lakes region of United States, 

 while in cats in the same region goiter is practically unknown. 

 The goiter of the newborn of mothers with thyroid hyperplasia 

 may be (1) primarily hereditary, that is, due to defects in the 

 germ plasm, or (2) it may be due to some temporary metabolic 

 disturbance in the mother, — toxins or abnormal concentration of 

 normal products of metabolism, acting alike both on the maternal 

 and on the fetal thyroid. If the fetal goiter is due primarily to 

 the constitution of the ovum rather than to the maternal environ- 

 ment during intrauterine life, we would expect the goitre to persist 

 in varying degrees after birth. We would also expect to meet with 

 fetal goiter in the case of mothers with colloid goiters, because the 

 colloid state appears to be preceded by active hyperplasia. On 

 the other hand, if the fetal goiter is due primarily to some intoxica- 

 tion or temporarily altered metabolism of the mother, acting 

 alike on the fetal and on the maternal thyroid so as to produce 



