CHAPTER XXXIII 

 FCETAL LIFE DEVELOPMENT AFTER BIRTH DEATH 



Duration of pregnancy Size, weight and position of the foetus Multiple pregnancy Cause 

 of the first contractions of the uterus in normal parturition Involution of the uterus 

 Meconium Dextral preeminence Development after birth Ages Death. 



As the development of the ovum advances, the uterus becomes en- 

 larged and its walls are thickened. The form of the organ, also, gradu- 

 ally changes, as well as its position. Immediately after birth its weight 

 is about a pound and a half (680 grams), while the virgin uterus weighs 

 less than two ounces (56.7 grams). The neck of the uterus, while it be- 

 comes softer and more patulous during pregnancy, does not change its 

 length, even in the latest periods of utero-gestation. The changes in the 

 walls of the uterus during pregnancy are important. The bloodvessels 

 become much enlarged, and the muscular fibres increase immensely in 

 size, so that their contractions are very powerful when the foetus is 

 expelled. 



It is evident that on account of the progressive increase in the size 

 of the uterus during pregnancy, it can not remain in the cavity of the 

 pelvis during the later months. During the first three mon\hs, however, 

 when it is not too large for the pelvis, it sinks back into the hollow of 

 the sacrum, the fundus being directed somewhat backward, with the neck 

 presenting downward, forward and a little to the left. After this time 

 the increased size of the organ causes it te extend into the abdominal 

 cavity, so that its fundus eventually reaches the epigastric region. Its 

 axis then has the general direction of the axis of the superior strait of 

 the pelvis. 



The enlargement of the uterus and the necessity of carrying on a 

 greatly-increased circulation in its walls during pregnancy are attended 

 with a temporary hypertrophy of the heart. It is mainly the left ven- 

 tricle that is thickened during utero-gestation, and the increase in the 

 weight of the heart at full term amounts to more than one-fifth. After 

 delivery, the weight of the heart soon returns nearly to the normal 

 standard. 



Duration of Pregnancy. The duration of pregnancy, dating from a 

 fruitful intercourse, is variable within certain limits. The method of 



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