A System of midwifery : including the diseases of pregnancy and the puerperal state . that reached in the second occipitoanterior position. Withreference to the posture of the woman, the sagittal -mure is traceddownwards and forwards, where it ends in the large lozenge-shapedanterior fontanelle : while, in the contrary direction, it may he followed 804 MECHANISM OF LABOR. [Oil A P. upwards and backwards to where it terminates in the posterior fonta-nelle. This point is of paramount importance in the diagnosis of theposition, for when, in any case, we find that the great fontanelle iswithin eas


A System of midwifery : including the diseases of pregnancy and the puerperal state . that reached in the second occipitoanterior position. Withreference to the posture of the woman, the sagittal -mure is traceddownwards and forwards, where it ends in the large lozenge-shapedanterior fontanelle : while, in the contrary direction, it may he followed 804 MECHANISM OF LABOR. [Oil A P. upwards and backwards to where it terminates in the posterior fonta-nelle. This point is of paramount importance in the diagnosis of theposition, for when, in any case, we find that the great fontanelle iswithin easy reach of the examining finger, our suspicions should atonce be excited, and the nature of the position carefully ascertained. So soon as the head becomes engaged in the brim, one of two thingsmay occur. In the one case, the occiput is driven, by the propulsiveforce communicated through the spinal column, downwards in advanceof the forehead, as in occipitoanterior cases ; in the other, the occiputis arrested, and the force being thus transferred to the frontal pole of Fir,. Third cranial position. the long diameter, that pole precedes the other in its descent. Whetherthe forehead or the occiput thus descends, there is, in the great majorityof cases, no barrier to the termination of the labor by the unaidedefforts of nature, although such cases are more or less the head, therefore, is placed in the third position, the labor mayterminate in two ways, either by rotation into the second position, orby the forehead passing under the pubis. As the former is the rule,and the latter a somewhat rare exception, we shall first consider themechanism according to which, in the great majority of cases, suchlabors terminate. The natural termination of the third position is by a movementwhich in extent far exceeds the ordinary rotation of the head. Thefacility with which this occurs depends in no small measure upon thecapacity of the pelvis. For nothing is more essential


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Keywords: ., bookcentury1800, bookdecade1870, booksubjectobstetrics, bookyear1