Unicornuate uterus: case reports of heterogenous presentations challenging clinical diagnosis and management

Abstract

The müllerian or paramesonephric duct appears on either side, lateral to each wolffian duct, approximately 37 days after fertilization and grows medio-caudally towards the urogenital sinus. They are the primordial anlage of female reproductive tract that differentiate to form the fallopian tubes, uterus, uterine cervix and upper 2/3rd of vagina. A wide variety of mullerian duct malformations result from agenesis, unilateral maturation with incomplete/absent opposite side, absent/faulty midline fusion or defective canalisation of the two mullerian ducts. According to ESHRE (European society of human reproduction and embryology) and ESGE (European society of gynecological endoscopy) classification system for female genital malformations, unicornuate uterus falls in class U4. The incidence of mullerian duct anomalies is around 3.2%. The prevalence with imaging ranges from 0.4 to 10%. The most common anomaly found is arcuate uterus followed by septate, bicornuate, didelphic and unicornuate uterus in descending order. Unicornuate uterus, the least common of all occurs in 1 in 4020 women, a rudimentary horn is present in about 84% of the cases. Herein we report three rare cases of I and II trimester ectopic pregnancy in non-communicating rudimentary horn of unicornuate uterus.