Unicornuate uterus

A unicornuate uterus represents a uterine malformation where the uterus is formed from one only of the paired mullerian ducts while the other mullerian duct does not develop or only in a rudimentary fashion. The sometimes called "hemi-uterus" has a single horn linked to the ipsilateral fallopian tube that faces its ovary.

Etiology

The uterus is normally formed during embryogenesis by the fusion of the two mullerian ducts. If one of the ducts does not develop, only one mullerian duct contributes to the uterine development. This uterus may or may be not be connected to mullerian structure on the opposite site if the mullerian duct on that site undergoes some development. A unicornuate uterus has a single cervix and vagina.Associated defects may affect the renal system, and less common, the skeleton.

The condition is much less common than these other uterine malformations: arcuate uterus, septate uterus, and bicornuate uterus. While the uterus didelphys is estimated to occur in 1/3,000 women, [cite journal |author=G.F. Grimbizis, M.Camus, B.C.Tarlatzis, J.N. Bontis, P.Dervoey |title=Clinical implications of uterine malformation and hysterscopic treatment results.| journal=Human Reproduction update, vol 7,no 2,pp 161-174,2001. PMID 11284660] the unicornuate uterus appears to be even more infrequent with an estimated occurrence of about 1/4,000.cite journal |journal=Fertil Steril. 2008 Apr 24.| title=Pregnancy outcomes in unicornuate uteri: a review.| author=Reichman D, Laufer MR, Robinson BK.PMID 18439594]

Presentation

Women with the condition may be asymptomatic and unaware of having a uniconuate uterus; normal pregnancy may occur. In a review of the literature Reichman et al analyzed the data on pregnancy outcome of 290 women with a a unicornuate uterus. 175 women had conceived for a total of 468 pregnancies. They found that about 50 % of patients delivered a live baby. The rates for ectopic pregnancy was 2.7%, for miscarriage 34 %, and for preterm delivery 20 %, while the intrauterine demise rate was 10 %. Thus patients with a unicornuate uterus are at risk for pregnancy loss and obstetrical complications.

Rudimentary horn

A unicornuate uterus may be associated with a rudimentary horn on the opposite site. This horn may be communicating with the uterus, and linked to the ispilateral tube. Occasionaly a pregnancy may implant into such a horn setting up a dangerous situation as such pregnancy can lead to a potentially fatal uterine rupture. Surgical resection of the horn is indicated. [cite journal |journal=J Coll Physicians Surg Pak. 2008 Jan;18(1):53-4.|title=Rupture of non-communicating rudimentary uterine horn pregnancy.| author=Dhar H.PMID 18452672]

Diagnosis

A pelvic examination will typically reveal a single vagina and a single cervix. Investigations are usually prompted on the basis of reproductive problems.

Helpful techniques to investigate the uterine structure are transvaginal ultrasonography and sonohysterography, hysterosalpingography, MRI, and hysteroscopy. More recently 3-D ultrasonography has been advocated as an excellent non-invasive method to evaluate uterine malformations.cite journal |author=Woelfer B, Salim R, Banerjee S, Elson J, Regan L, Jurkovic D |title=Reproductive outcomes in women with congenital uterine anomalies detected by three-dimensional ultrasound screening |journal=Obstet Gynecol |volume=98 |issue=6 |pages=1099–103 |year=2001 |month=December |pmid=11755560 |doi= |url=http://www.greenjournal.org/cgi/pmidlookup?view=long&pmid=11755560]

Management

Patients with a unicornuate uterus may need special attention during pregnancy as pregnancy loss, fetal demise, premature birth, and malpresentation are more common. It is unproven that cerclage procedures are helpful. A pregnancy in a rudimentary horn cannot be saved and needs to be removed with the horn to prevent a potentially fatal rupture of the horn.

References

External links

* [http://www.wegrokit.com/uterineanomalies/gallery.htm Image gallery]