CHANGES OF THE PRESENTATIONS AND POSITIONS.
It is by no means uncommon to see presentations and positions change during pregnancy and even at the beginning of labor. Favored by any condition that prevents perfect fcetal accommodation, these changes have been especially studied of late years, and to the labors of Crede, Hecker, Heyerdahl, Valenta, Schroeder, Schultze, Spiegelberg, Sutugin and Fasbender, we owe our precise ideas upon the subject. The further we are from the end of pregnancy, the more frequent are these changes.
Schroeder concludes from his observations: 1st. The foetal presentation rarely remains motionless from the end of the seventh or the eighth month until the time of labor. In 113 women examined once only, change of presentation was encountered in 31.86 per cent. of the cases. Primipara3 30 per cent.; multiparte 36.36 per cent. In 56 women examined twice, change of presentation occurred in 59 per cent. of the cases. Primiparte 52 per cent.; multipara3 66 per cent. In 33 women examined three times, change of presentation was found in 76 per cent. of the cases. Primiparm 72 per cent.; multiparte 88.9 per cent. In 28 women examined several times, change of presentation was found in 89.3 per cent. of the cases. Primiparte 89.3 per cent.; multiparte 100 per cent.
2d. The changes are less common in primiparte than in multipara3. 3d. They become rarer as we approach term.
4th. Even when the head is fixed in the superior strait, change of pres entation is possible.
5. When the head is completely within the lesser pelvis, change of posi tion only occurs in 10 per cent. of the cases.
6th. Changes are more common with contracted than with normal pelves.
The following table, taken from Schroeder, will show the frequency and variety of these changes of presentations and of positions: Fasbender, on examination of 418 cases, has come to the following con clusions: 1st. In primiparte and multiparte, change of presentation is the rule.
2d. The number of changes found increases with the number of exami nations made, and with the number of previous pregnancies.
3d. In multipane, seven or more examinations have not enabled us to prove fixity. In primiparte, on the contrary, the presentation has re mained fixed during five explorations.
4th. When six examinations have proved fixity, the seventh has never failed to show a change.
5th. Changes of position are more frequent than changes of presenta tion.
6th. Primiparity gives us more changes of position than of presenta tion; multiparity does the reverse.
7th. The older the multiparte, the more changes occur.
8th. Pelvic contractions favor mutations; and large pelves, on the con trary, favor fixity.
9th. In all cases a large figure favors frequency of change.
10th. Chronic uterine catarrh with abundant secretion, uterine contrac tions, energetic action of the abdominal muscles, appear to favor muta tions.
11th. A pendulous abdomen is not a cause of more frequent mutation. 12th. Neither is a large development of the abdominal cavity. The contrary is the case in hydramnios.
13th. An elevated position of the fcetal presenting part at the ninth, and more especially at the tenth month, favors change.
14th. When the head is fixed above or within the lesser pelvis, muta tions are rarer.
15th. During pregnancy, an ascent of the foetal part, with or without mutation, may be recognized in successive examinations.
16th. A pronounced deviation of the fcetal part towards one of the iliac bones seems to favor changes of presentation.
17th. The presentation appears to be more fixed and constant in in fants whose hearts beat with a small average frequency.
18th. The subjective force of fcetal movement appears to be increased by mutation.
19th. In primiparte, male children, and in multiparte, female children, most often change their situation. On the whole, sex seems to have no marked influences.
20th. It is in cases where there has been mutation that we have the best developed children, especially as regards length.