The female gubernaculum: role in the embryology and development of the genital tract and in the possible genesis of malformations.

The female gubernaculum is an embryonic structure that gives rise to the uterine round ligament and seems to be important in Müllerian development. In the absence of androgens and anti-Müllerian hormone, the paramesonephric or Müllerian ducts complete their invagination and development, interfering with the connection of the tissue column that begins at the inguinal cone (the gubernaculum) and targets the mesonephric duct and caudal ligament of the gonad. The gubernaculum then grows over the Müllerian ducts, incorporating its muscular fibres. Outside and above this point, the Müllerian ducts give rise to the Fallopian tubes, whereas medially to the point of insertion of the gubernaculum, the Müllerian ducts develop into the normal uterus, the adequate formation of which is also induced by the mesonephric ducts. Diverse human anatomical and physiological characteristics such as the simplex uterus, as well as pathological conditions and certain female genital malformations, could be related to gubernaculum dysfunction. The main conclusions in this article are: (1) The female gubernaculum is the origin of the uterine round ligament but probably not of the uteroovarian ligament. Gubernacula are composed of muscular fibres that probably derive from the abdominal wall and that, when fixed and fused with the Müllerian ducts, allow or induce, together with the mesonephric ducts, the adequate development and formation of the uterus. (2) The female gubernaculum seems to be responsible for many of the specific human characteristics of Müllerian development, including the uterus simplex, the anteflexion and low intra-abdominal position of the uterus, and the disposition of uterine muscular fibres. (3) The female gubernaculum seems to be related to pathologies arising from the round ligaments and inguinal hernia. Likewise, certain uterine malformations (e.g., didelphys uterus, Rokitansky syndrome) and accessory and cavitated uterine masses might be related to gubernaculum dysfunction.

Human (and some other primates') uterine teres ligament represents a mammalian developmental novelty.

BACKGROUND: The primordia of the structures developing into the mammalian male cremaster sacs emerge as well in females fetuses. In most species the structures developing from these primordia in females remain inconspicuous: the so-called uterine teres ligament consisting of a slender part across the uterine broad ligament and a more or less developed bulbous structure at the site where this ligament inserts into the inguinal abdominal bottom. Not many data are available concerning the growth, development, or function of the uterine teres ligament. In humans--and also in other "higher" female primates--the uterine teres ligament is a major structure consisting mainly of smooth musculature. It is attached to the ventral aspect of the tubo-uterine junction. From there it courses across the uterine broad ligament and extends, retroperitoneally, to the inguinal region where it pierces through the inguinal canal to end in the tissues ventral of the pubic bones. OBSERVATIONS: Analysis of the fetal development of the human uterine teres ligament, as compared with that of various other non-primate mammals, offers an explanation for its unusual anatomical condition. Evidence is conferred that, in human fetuses, there is no counterpart for the slender ligament across the broad ligament in other mammals. Instead, the homologue of the rudimentary bulbous structure in the abdominal bottom of non-primate females develops into a strong muscular structure which is directly connected to the (para-)menonephric duct wall. CONCLUSION: It is concluded that the human uterine teres ligament is to be judged a structure different from that of other, non-primate, mammals. It is speculated that the unusual structure of the human teres ligament is related to one or more of the many unusual features of human uterine development: as a single organ (uterus simplex), with a position deep in the abdominal cavity below the pelvic brim, and far away from the posterior abdominal wall. The unusual anatomical position may require an unusual construction of the uterine suspensory apparatus of which the teres ligament is one component.

[The mesorectum in females. Evolution of the fascia pelvis parietalis in pelvic dissection]. / Le méso-uro-génito-rectal chez la femme. Evolution du fascia parietalis pelvien dans l'excavation pelvienne.

The authors used dissections of adult and fetal female cadavers to describe the meso uro-genito-rectum or visceral pelvic fascia, visceral prolongation of the parietal pelvic fascia. This meso uro-genito-rectum consists of two parts: 1 The anterior part: formerly the umbilico-prevesical aponeurosis, called the meso-bladder in this text. 2 The posterior part: the meso recto-vagina. While the meso-rectum was already well described using the term "rectal wing" or para-rectum, knowledge of the meso-vagina under the meso-cervix (or paracervix or Mackenrodt's cardinal ligament) was poorly defined, and concerning the following in particular: * its posterior prolongation by the meso-rectum, * its relations with the middle rectal pedicle (formerly the middle hemorrhoidal pedicle),* its helicoidal appearance when in anatomical position.

The anatomy of the female gubernaculum is different from the male.

The round ligament, or female gubernaculum, is believed to terminate in the labium majorum. In the 30-week old male foetus, however, the gubernaculum ends outside the external ring, later migrating into the scrotum under androgenic control. We studied the round ligament anatomy in the female to define its position and to see whether it reaches the labium. Post-mortem examination of 10 females (0-11 years), dying of non-genital disorders defined the anatomy of the round ligament by dissection and photography. The round ligament ended just outside the external ring in all females, with neither attachment, nor extension, to the caudal labium. A short processus vaginalis (canal of Nuck) was found in 1 patient. This study showed that the round ligament fails to reach the caudal labium, which is the homologue of the hemiscrotum. The migration of the male gubernaculum into the scrotum to enable descent of the testis does not occur in females. The description of the round ligament in standard textbooks of anatomy should be amended.