Anomalies Of Uterus
Nur Amalina bt. Aminuddin Baki082012100067
Objective
• The student should be able to :Identify the classification of uterus anomalies
based on their causesList the anomalies of uterus under each
classification
Introduction
• Anomalies of uterus can be classified based on their cause:absent or incomplete migration of the
paramesonephric duct partial or complete failure of the lower parts of
the two paramesonephric ducts (Müller) to fuse failure of resorption of the median dividing wall
of the two paramesonephric ducts • Cervix = Collis (hill) , Uterus=Cornis (horn)
Genes involved
Gene WNT4 • Ovary Determining Gene• upregulates DAX1 (nuclear hormone receptor
family) that inhibit SOX9• Regulate expression other genes responsible for
for ovarian differentiation TAFII105 gene - a subunit for TATA- binding
protein for RNA polymerase in ovarian follicular cells.
Development of Uterus and Vagina
• Second part of Paramesonephric ducts fuse in midline,then canalize to form uterus.
• When paramesonephric duct reaches urogenital sinus,two evaginations (sinovaginal bulbs) grow out, proliferate and form vaginal plate.
• Vaginal outgrowth entirely canalized by 5th month.
Absent or Incomplete Migration of the Paramesonephric Duct
• an atresia (Absence or abnormal narrowing of opening ) and/or complete or incomplete aplasia(failure to develop or function) of the uterus.
• Example:• Unicornuate uterus (complete aplasia)
– One half of uterus is absent
•Atresia of cervixAtresia of both muller tube
•Atresia of vaginaSinovaginal bulbs fail to fuse
•mayer-rokitansky-küster-hauser syndrome
Uterus and upper vagina absent
Failure of the Lower Parts of Müller to Fuse
• Uterus didelphys( G:delphys = womb)– Double uterus, double cervix and double vagina
• Uterus bicornis bicollis– Double uterus, double cervix, one vagina
• Uterus bicornus unicollis– Double uterus, one cervix, one vagina
• Uterus arcuatus– Uterus slightly endented
Failure of Resorption of the Median Dividing Wall
• The leads to a septated uterus:• Uterus septus
from the body to the uterine cervix• Uterus subseptus subtotalis unicollis
only in the body region• Uterus subseptus unicornis bicollis
only in the cervical region
Uterus septus Uterus subseptus subtotalis unicollis
Uterus subseptus unicornis bicollis
Conclusion
• Defect of migratory– Unicornuate uterus, atresia of cervix and vagina
• Defect of fusion– Uterus didelphys, uterus bicornis bicollis , uterus
bicornus unicollis and uterus arcuatus• Defect of resorption
– Uterus subseptus subtotalis ,Uterus subseptus subtotalis unicollis and Uterus subseptus unicornis bicollis
Reference
• Inderbir Singh and GP Pal, Human Embryology, 8th edition, Macmillan India Limited, 2007,page 251.
• T.W. Sandler, Langman’s Human Embryology, 11th Edition,Wolters Kluwer,2007, page 254.