A uterine malformation is a type of female genital malformation resulting from an abnormal development of the Müllerian duct(s) during embryogenesis. Symptoms range from amenorrhea, infertility, recurrent pregnancy loss, and pain, to normal functioning depending on the nature of the defect. Types
The American Fertility Society (now American Society of Reproductive Medicine) Classification distinguishes:

Class I—Müllerian agenesis (absent uterus). This condition is represented by the hypoplasia or the agenesis (total absence) of the different parts of the uterus:
Vaginal hypoplasia or agenesis
Cervical hypoplasia or agenesis
Fundal hypoplasia or agenesis (absence or hypoplasia of the fundus of the uterus)
Tubal hypoplasia or agenesis (absence or hypoplasia of the Fallopian tubes)
Combined hypoplasia the agenesis of different part of the uterus
This condition is also called Mayer-Rokitansky-Kuster-Hauser syndrome. The patient with MRKH syndrome will have primary amenorrhea. Class II—Unicornuate uterus (a one-sided uterus). Rare condition in which a partial or complete lack of one Müllerian duct is present. The uterus has a typical "banana shape" on imaging systems. This condition can be sub-classified in:
Communicating: a rudimentary uterine horn is formed and it presents a cavity that communicates with the body of the uterus
Non-communicating: a rudimentary uterine horn is formed and it presents a cavity that does not communicate with the body of the uterus
No cavity: a rudimentary uterine horn is present without any cavity
No horn: there is no rudimentary uterine horn, just the functioning one is presentClass III—Uterus didelphys, also uterus didelphis (double uterus). Both Müllerian ducts develop but fail to fuse, thus the patient has a "double uterus".
This procedure greatly decreases the rate of miscarriage for women with this anomaly. Prevalence
The prevalence of uterine malformation is estimated to be 6.7% in the general population, slightly higher (7.3%) in the infertility population, and significantly higher in a population of women with a history of recurrent miscarriages (16%). See also
Uterus didelphys
Uterus § Other animals – where some malformations in humans are "normal"

References
External links
BBC NEWS - Triplets for woman with two wombs