ABDERHALDEN S SERODIAGNOSIS OF PREGNANCY 263 



Considerable experience is required in making these readings, and 

 the novice should practise well before conducting diagnostic tests. 



Individual readings by different persons may vary 0.02, and in 

 order to secure absolute certainty Abderhalden gives 0.04 as the limit 

 for error. 



A large margin for error will result if the primary reading is taken 

 when the tube is cold, as it is immediately after being filled. Only that 

 reading taken after the tube has been in the incubator for at least one or 

 two hours is to be taken as the guide for determining the amount of 

 digestion according to the degree of rotation. 



The greatest source of error lies in the observer himself. One must 

 be trained to make the readings in about thirty seconds; the eye soon 

 grows tired, and the readings are then unreliable. 



PRACTICAL VALUE OF ABDERHALDEN'S PREGNANCY TEST 



1. It is too soon to express a definite opinion of the specificity and 

 diagnostic value of this reaction. Most reports have been based upon 

 the dialyzation method. According to Abderhalden, 1 Veit, 2 Frank 

 and Hermann, 3 Franz and Jarisch, 4 Petri, 5 Judd, 6 Schwartz, 7 and 

 others the ferment is highly specific, and the test is of considerable value 

 in the diagnosis of pregnancy. 



2. The reaction appears in the middle of the second month, and dis- 

 appears in from ten to fifteen days after pregnancy has been interrupted, 

 regardless of whether the fetus is born before, at, or after the normal 

 period of gestation. Nursing has no effect upon the reaction. 



3. The reaction has been recommended in making an early diagnosis 

 of pregnancy, when the symptoms and physical signs are indefinite," 

 also in making the differential diagnosis between pregnancy and tumors 

 in the pelvis. 



4. The reaction is likely to be positive in hydatidiform disease and 

 in chorio-epithelioma. 



5. In acute febrile and cachectic diseases the serum may contain 

 relatively large amounts of dialyzable compounds; positive reactions 

 have occurred in tuberculosis of the female generative organs. 



1 Munch, med. Wochenschr., 1912, lix, 1305; 1912, lix, 1939 and 2172. Berl. 

 tierarzt. Wochenschr., 1912, xxvii, 446; 1912, xxviii, 685 and 774. Zeitschr. f. 

 physiol. Chem., 1912, Ixxvii, 249. Deutsch. med. Wochenschr., 1912, xxxviii, 2160 

 and 2252. Prakt. Ergebn. d. Geburtsh. u. Gynak., 1910, ii, 367. 



2 Zeitschr. f. Geburt. u. Gyn. 1913, 77, 463. 



3 Berl. klin. Wochenschr., 1912, No. 36. 



4 Wien. klin. Wochenschr., 1914, 44, 144. 



6 Centralbl. f. Gyn., 1913, No. 7. 6 Jour. Amer. Med. Assoc., 1913, Ix, 1947. 



7 Interstate Med. Jour., St. Louis, 1913, xx, 195. 



