380 FCETAL DYSTOKIA. 



Anomalies in, and Disease of, the Fcetal Membranes. 



It is very rare indeed, so far as published observations are evidence, 

 that anomalies in, or disease of, the foetal membranes prove an obstacle 

 to birth. That they may sometimes do so, however, is evident from 

 what we have previously described. As Franck justly remarks, it is 

 not unlikely that the retention of the foetal membranes after birth is 

 due, in many cases, to inflammation of the placenta {i)lacsntitis). A 

 not unfrequent condition of the membranes is congestion of, or extra- 

 vasation into, the placenta, rupture of the capillaries [capillary 

 aiJoplexy), and haemorrhage between the placenta materna and placenta 

 uterina. Partial separation of the two placentaB is also not very un- 

 common in the Mare ; and metrorrhagia may be due, at times, to 

 2:)laccnta pravia. Such haemorrhage, when it occurs in the uterus (see 

 Fig. 53, p. 88), and the blood mixes with the uterine milk, gives rise 

 to a chocolate-coloured fluid between that organ and the foetal mem- 

 branes ; and in the asphyxia and intra-uterine respiration (pulmonary) 

 of the foetus, this reddish-coloured fluid is often present in the lungs. 



Hartmann alludes to a case in which the chorion papillae of an 

 aborted Foal were small, pale, hard, and cartilaginous ; and Broers^ 

 describes two foetuses in the uterus of a Cat, on the inner surface of 

 the membranes of one of which were numerous vesicular extravasa- 

 tions, while the other could scarcely be recognised. It may be surmised 

 that many abortions or foetal deaths are due to disease of the ]Dlacentae. 



The foetal membranes may be too thick and resisting, or too thin and 

 friable. In the first condition, they resist the labour pains too long, 

 and after the os uteri is completely dilated they may be found intact 

 outside the vulva ; the foetus may even be expelled in them. Such 

 tenacious membranes may, to a certain extent, hinder delivery — though 

 they seldom, if ever, produce dangerous consequences, except to the 

 foetus. 



Very thin membranes may, on the contrary, not resist the uterine 

 contractions for a sufficient length of time, and therefore rupture before 

 the OS is sufficiently dilated. The consequent escape of the " waters " 

 will render labour longer and more difficult. The utero-vaginal canal is 

 dry and retentive, and the contractions of the uterus are weaker and 

 much less effective. 



The treatment for both of these conditions has been already 

 indicated. 



At p. 368 we alluded to adhesions between the foetus and its mem- 

 branes, and the uterus, as a cause of protracted or impotent labour. 

 We have now to refer to adhesion of the membranes to each other, or 

 to the foetus only, as a cause of difficult labour. 



These adhesions are generally of the nature of fibrinous bands passing 

 between the membranes, or from the surface of the young creature's 

 body to the interior of its envelopes, due to the development of some 

 local inflammation. Such cases are certainly rare, but their occurrence 

 must nevertheless be taken into account. 



Eainard- mentions an instance in which a hairy band or cord attached 

 the envelopes to the head of the foetus — a shred of skin having prob- 

 ably been partially detached from the forehead, from a kick received by 



^ Caustatt's .Taliresbericht, 1861, p. 53. 

 - Op. cit., vol. i., p. 492. 



