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1. the region of the body between the anus and the genital organs, including some of the underlying structures
2. the nearly diamond-shaped surface of the human trunk between the thighs
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in man, the anatomical region that comprises the pelvic floor and is located between the apex of the coccyx posteriorly, the apex of the subpubic arch anteriorly, and the ischial tuberosities laterally.

In obstetrics, the perineum is the space between the anus and the posterior commissure of the labia majora. Its bony foundation includes the pelvic ischial tuberosities, the pubic bone, and the coccyx. The perineum also contains muscles, ligaments, fatty tissue, vessels, nerves, and some internal organs. Shaped like a rhombus, it is divided into two triangles by a line that joins the ischial tuberosities; the male urethra or the female urethra and vagina pass through the anterior urogenital triangle. The rectum passes through the posterior, or anal, triangle.

Injuries to the perineum can consist of closed or open wounds. They arise most often with fractures of the pelvic bone when there is a great displacement of fragments (indirect mechanism) or with a blow to the perineum (direct mechanism). On the average, 10 percent of all women suffer perineal ruptures during childbirth, most often with the birth of the first child. The most common diseases of the perineum are suppurative processes near the rectum upon injuries to the rectal mucosa. Surgery is required to treat injuries and suppurative diseases of the perineum.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


The portion of the body included in the outlet of the pelvis, bounded in front by the pubic arch, behind by the coccyx and sacrotuberous ligaments, and at the sides by the tuberosities of the ischium.
The region between the anus and the scrotum in the male, between the anus and the posterior commissure of the vulva in the female.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
A search of PubMed and the Directory of Open Access Journals found no studies in Cambodia on the perineum, perineal length or perineal trauma.
Data collected were: parity, age at time of pregnancy, type of delivery (normal vaginal or vaginal with vacuum extraction), state of perineum (intact, torn and/or episiotomy), infant birth weight, mother's height, mother's weight gain during pregnancy.
"The perineum of Asian women is short, it is not long, like European women's." (Obstetrician No.1)
As a result of his findings, he now pays more attention to the possibility of severe laceration in women with a short perineum. When he performs an episiotomy in such women, he is more likely to do a mediolateral incision than a midline incision in the hope that it will lower their risk of a severe tear.
Results Among women without a previous vaginal birth, 24.3% from the perineal massage group and 15.1% from the control group were delivered vaginally with an intact perineum, for an absolute difference of 9.2% (95% confidence interval, 3.8%-14.6%; P = .001; number needed to treat = 11).
Recommendations for clinical practice This large study provides data suggesting that the practice of third trimester perineal massage can increase the likelihood that women without a previous vaginal birth will deliver with an intact perineum. Unfortunately, there was no clinically significant reduction in the episiotomy rate or the incidence of third- and fourth-degree tears, which account for most of the morbidity associated with perineal birth trauma.
The increased risk conveyed by a shorter perineum remained after controlling for operative vaginal delivery, use of episiotomy, and fetal weight.