PRESENTATIONS OF THE FCETUS, 



227 



ties of the young creature are already sufficiently developed to bring 

 about this result, which may, after all, be due to some reflex action. 

 However this may be, it is certain that the foetus is very far, from being 

 always in this favorable position, and that the resources of art are often 

 needed to remedy the false positions the young creature may have as- 

 sumed at the termination of gestation. 



In studying the various positions and attitudes the foetus assumes at 

 birth, and the consequent presentations it offers towards the anterior 

 opening of the pelvis, there is to be considered (i) the region of its body 

 which is first presented to the pelvic inlet, and (2) the relations of, or 

 correspondence between, this region and the shape and dimensions of 

 the pelvic cavity itself. 



The first has been designated \\i^ presentation, and the second i\\& posi- 

 tion of the foetus • and the inlet, instead of the outlet, of the pelvis is con- 

 sidered in this respect, because it is the most important in practice, and 

 the position may be altered either spontaneously or artificially during 

 labor ; indeed, this alteration has often to be effected by the obstetrist 

 in order to render birth possible, 



SECTION I. PRESENTATIONS, 



The presentation results from the part of the foetus which first offers 

 itself at the pelvic inlet — that region of the young creature \vhich the 

 hand of the obstetrist immediately meets on being passed into the os, 

 and which is directly opposite the inlet. In this sense the head, fore 

 feet, hind feet, croup, etc., are said to be presented, according as one or 

 other of them first offers itself on exploration. 



These presentations are extremely variable, as any part of the foetus 

 may occupy this situation ; though so far as description and compreli^n- 

 sibility are concerned, their study can be greatly simplified. As Rainard 

 says : " The foetus, when covered by its envelopes, is oval shaped, or like 

 an olive, which it is desired to pass down the neck of a bottle, and which 

 may be presented to this in three ways — either by one of its two ends or 

 by its middle." These ends are the anterior part of the chest in front, 

 and the croup behind ; and it is these parts on which the classification of 

 'these presentations is based. This classification gives two longitudinal, 

 and an anterior and posterior presentation ; and as the foetus may also 

 offer itself across the long axis of the uterine cavity, we have a transverse 

 presentation, which^ may again be dorso-himbar or sterno-abdominal, accord- 

 ing to the side of the foetus which presents. These four fundamental 

 presentations are, therefore : 



1. Anterior Presentation. — The chest of the foetus presents towards the 

 [inlet, and is preceded, accompanied, or followed by the head and fore 



limbs: the situation and direction of which may vary without altering the 

 I essential features of the presentation. 



2. Posterior Presentation. — The croup or breech is facing the inlet, and 

 the presence or absence of the limbs there only constitute varieties of the 

 presentation. 



3. Dorso-lumbar Presentation. — Any portion of the upper part of the 

 (body opposite the inlet. Lecoq and Rainard admit presentations of the 



withers, back, loins, shoulder or haunch, as distinct presentations ; but I 

 agree with Saint-Cyr in declaring the distinction to be practically useless. 

 On exploring the pelvic cavity, no matter what part of the back is first 



