HYDATIFORM DEGENERATION IN TUBAL PREGNANCY. 241 



The incidence of hydatiform degeneration in the 108 tubal pregnancies classed 

 as pathologic is 45, or 41.7 per cent of the whole. This is a somewhat higher 

 incidence than was obtained in the uterine abortuses classed as pathologic, and 

 may be accounted for partly, or even wholly, by the greater incidence of young 

 specimens in the tubal series. That the tubal specimens undoubtedly were younger 

 follows from common knowledge regarding tubal pregnancies alone, but it also 

 is shown by the average menstrual age, which was 43.4 days in 25 tubal as com- 

 pared with 66.6 days in 51 uterine specimens. Moreover, 32 of the 48 tubal speci- 

 mens of hydatiform degeneration, or 66.6 per cent, fall into the first two groups, 

 thus again showing that the majority are small, young specimens. However, 

 by comparing the percentage of hydatiform degeneration in the first five groups 

 of the pathologic tubal and uterine cases composed of conceptuses of approximately 

 the same age, the same difference in incidence is noticeable, it being almost twice 

 as great in the tubal as in the uterine series. 



Although the incidence of hydatiform degeneration among the pathologic 

 tubal specimens is but slightly higher than that among the pathologic uterine 

 specimens, the incidence of hydatiform degeneration in all tubal specimens con- 

 tained among both the normal and pathologic is twice as high as that among the 

 same classes of uterine specimens. This can be explained only partly by the fact 

 that a larger proportion of the tubal specimens are young and pathologic. The 

 pathologic tubal specimens form 70.5 per cent of 153 normal and pathologic tubal 

 specimens found among the first 1,200 accessions, but the pathologic uterine 

 specimens form only 33.6 per cent of the normal and pathologic uterine groups 

 among the same accessions. But the real question remains, for the incidence of 

 hydatiform degeneration among the specimens classed as pathologic was essentially 

 the same in tube and uterus. Hence an increased incidence of 200 per cent in hy- 

 datiform degeneration in the tubes may be due to the less favorable nidus found 

 there. If so, it throws a very significant light upon the probable cause of hydati- 

 form degeneration, which would seem to lie in the conditions surrounding the 

 implantation and early development rather than in the ova or spermatozoa them- 

 selves. 



The conclusion, reached in a study of uterine specimens, that hydatiform 

 degeneration is absolutely less, not more, frequent near the menopause is confirmed 

 also by the study of the tubal specimens. The average age of 20 women in the 

 tubal series was 33.9 years, as opposed to an average of 31 years obtained from 36 

 women in the uterine group. This age difference offers a tempting opportunity 

 for generalization, and did the statistics include thousands of cases one might be 

 willing to say that it points to a progressive change as cause, which begins in the 

 uterus and finally reaches the tubes. But strangely enough, the average number of 

 years of married life of 15 women in the tubal series is exactly the same as that of 

 29 women in the uterine series, or 7.1 years. This fact at once guards against a 

 venturesome hypothesis, for it allows a no longer period for the supposed ascending 

 change to reach the tubes than the uterus. 



