The Form of the Pregnant Uterus 377 



character as to be termed abnormal and forms no particular im- 

 pediment to labor. In other cases, the uterus becomes displaced 

 on account of the ruptured prepubian tendon (which see) or it 

 may become rotated upon its long axis, inducing torsion of the 

 uterus, which we shall consider later. 



The influence of the gravid uterus upon neighboring organs 

 is comparativeh^ unimportant except in a purelj' mechanical way. 

 It does not interfere materially with an)' of the abdominal 

 viscera. When the fetus attains considerable size and rests 

 against the diaphragm, it may mechanically impede respiration 

 to a slight degree. 



The influence of the gravid uterus upon the circulation of the 

 region has been claimed by some writers to be quite important. 

 Fleming states that, in the cow and mare, the gravid uterus ex- 

 erts an unfavorable compres.sion upon the blood vessels of the 

 hind limbs, vulva and rectum and causes engorgement of the 

 veins and lymphatics in these parts. In this way he accounts 

 for the edema of these parts so often observed in the later stages 

 of gestation in the mare. He thinks, also, that this edema is re- 

 ferable to some extent, in the mare and cow, to pressure upon the 

 saphena and mammary veins. It would be exceedingly difficult 

 to demonstrate this hypothesis upon anatomical grounds. In 

 woman, in her upright position, with the head of the fetus 

 normally resting against the pelvic inlet and the entire weight 

 of the fetus bearing upon these parts, it would seem reasonable 

 to expect .some interference with the return of blood from the 

 inferior extremity of the mother, and this is clinically true. 

 However, in our domestic animals in their quadrupedal position 

 this cannot well follow. In dropsy of the amnion in the cow 

 (which see), there is such a great collection of amniotic or 

 allantoic fluid that the patient is borne down by the immense 

 weight and cannot rise to her feet. Still, in the.se cases, dropsy 

 of the limbs is never seen, but they are on the contrary very clean 

 and free from any edema whatever. Both from an anatomical 

 and a clinical standpoint, the allegation that compression by the 

 gravid uterus causes edema of the posterior limbs and abdom- 

 inal floor is questionable ; the edema should probably be referred 

 to other than mechanical influences. 



The changes in volume, weight and position of the gravid 

 uterus, while they bring about some alterations in the position 



