In order to bring my subject before you within the allotted time, it will be necessary for me to confine myself largely to general statements, and to omit many desirable but time-consuming details.
First let me call attention to the peculiar qualities of the obstetric perineum, which, during the previous eight or nine months of passive congestion, has undergone an astonishing amount of development. The muscular tissue has become hypertrophied, the fascia thickened and strengthened, and the loose connective tissue2 proliferated, until the vaginal and vulval mucous membrane, under the stimulus of labor, roll out at the vulva, in much the same manner as the mucous membrane of the cervix rolls out at the os during prolonged congestion or inflammation about the broad ligaments. Towards the end of the first stage of labor in healthy young primaparæ, the vaginal orifice will admit a small hand with but little more
BYFORD HT. THE PRODUCTION AND PREVENTION OF PERINEAL LACERATIONS DURING LABOR, WITH DESCRIPTION OF AN UNRECOGNIZED FORM.. JAMA. 1886;VI(10):253-257. doi:10.1001/jama.1886.04250030001001