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.