Uterus didelphys is a malformation of the uterus, due to müllerian duct fusion failure. The result is a double uterus, set up as two separate cervices and often a double vagina (longitudinal vaginal septum). Each uterus has a single ‘horn’, linked to its own fallopian tube, with its own ovary. They function normally, except if there is a blockage further down, resulting in a build up of menstrual blood from one of the menstrual periods of one of the uteruses.
How does müllerian duct fusion failure happen?
As the foetus develops, the müllerian ducts fuse together to form the uterus, fallopian tubes, cervix, and the upper section of the vagina. A double müllerian system means a fusion failure, but for unknown reasons. The abnormality can affect the vagina and kidneys, and from time to time, the skeleton.
Other malformations of the uterus include the arcuate uterus, septate uterus, and the bicornuate uterus. It happens in about one in every 3,000 women, but true incidence is unknown.
- Usually asymptomatic
- Increased gynaecological complaints
- Dysmenorrhoea (painful periods)
- Dyspareunia (painful sex)
- Double vagina (vaginal septum)
- Breech births
- Premature births
- Pregnancy and birth complications
- Double pregnancies (one in each uterus) (with one triple pregnancy recorded)
Usually an examination will reveal a double vagina and double cervix, but not all. Imaging studies are likely to be undertaken to see what’s going on. It may be misdiagnosed as a complete uterine septum.
Pregnancy outcomes must be carefully monitored, since problems can quickly arise. A caesarean is often recommended.