The functions of the Corpus luteum. V.—Changes in the sterile horn during pregnancy, and their relation to changes in the Corpus luteum

Abstract

Evidence as to the precise role of the corpus luteum during pregnancy is contradictory, especially when different species are compared. Most observers agree that the presence of the corpus luteum is necessary during the early stages of gestation. During the second half of pregnancy, however, the removal of the corpus luteum in certain animals does not lead to immediate abortion. In the guinea-pig Loeb and Hesselberg (1917), Herrick (1928) and Courrier, Kehl and Raynaud (1929) have found that pregnancy may continue for some weeks after double ovariectomy, and Ash-Upmark (1926) has listed a large number of clinical cases in which ovariectomy in women has not disturbed pregnancy. The evidence for the rabbit (summarised by Hammond, 1925), is slightly contradictory, but tends to show that the corpus luteum is necessary during the whole of pregnancy, although this was not the conclusion of Niskoubina (1909). In the rat it appears that double ovariectomy towards the end of pregnancy does not always result in its premature termination (Marshall and Jolly, 1906). More definite information is available for the mouse (Harris, 1927 ; Parkes, 1928), where the presence of the corpus luteum is essential during the whole of gestation.