Bicornuate uterus

Bicornuate uterus
Other names	bicornate uterus
Two types of a human bicornuate uterus
Specialty	Gynaecology

A bicornuate uterus or bicornate uterus (from the Latin cornū, meaning "horn"), is a type of müllerian anomaly in the human uterus, where there is a deep indentation at the fundus (top) of the uterus.

Pathophysiology

A bicornuate uterus develops during

Diagnosis of bicornuate uterus typically involves imaging of the uterus with 2D or 3D ultrasound, hysterosalpingography, or magnetic resonance imaging (MRI). On imaging, a bicornuate uterus can be distinguished from a septate uterus by the angle between the cornua (intercornual angle): less than 75 degrees in a septate uterus, and greater than 105 degrees in a bicornuate uterus. Measuring the depth of the cleft between the cornua (fundal cleft) may also assist in diagnosis; a cleft of over 1 centimetre (0.39 in) is indicative of bicornuate uterus.^[2]

Classification

Bicornuate uterus is typically classified based on whether or not the division extends to the external cervical os. Bicornuate uteri with a division above the os are called bicornuate unicollis and those with a divided os are called bicornuate bicollis.

There is also a hybrid bicornuate uterus: External fundal depressions of variable depths associated with a septate uterus can be seen by laparoscopy, indicating the coexistence of the two anomalies. These cases are candidates for hysteroscopic metroplasty under appropriate sonographic and/or laparoscopic monitoring.^[4]

An obstructed bicornuate uterus showing uni or bilateral obstruction might also be possible. The unilateral obstruction is more difficult to diagnose than the bilateral obstructive. A delay in the diagnosis can be problematic and compromise the reproductive abilities of those cases.^[5]

Treatment

Bicornuate uterus typically requires no treatment.^[1] In those who do need treatment, metroplasty is the surgical correction of choice.^[2] Women who have recurrent miscarriage with no other explanation may benefit from surgery.^[6]

Epidemiology

The occurrence of all types of paramesonephric duct abnormalities in women is estimated around 0.4%.^[7] A bicornuate uterus is estimated to occur in 0.1–0.6% of women in the US.^[8] It is possible that this figure is an underestimate, since subtle abnormalities often go undetected.^{[citation needed]} Some intersex individuals whose external genitalia are perceived as being male may nonetheless have a variably shaped uterus. Women exposed in utero to diethylstilbestrol (DES) are at risk for this abnormality.^{[citation needed]}

In pregnancy

A bicornuate uterus is an indication for increased surveillance of a pregnancy, though most women with a bicornuate uterus are able to have healthy pregnancies.

Fetuses developing in bicornuate uteri are more likely to present breech or transverse, with the fetal head in one horn and the feet in the other. This will often necessitate cesarean delivery. If the fetus is vertex (head down), the two horns may not contract in coordination, or the horn that does not contain the pregnancy may interfere with contractions and descent of the fetus, causing obstructed labor.^[13]

Effect on intrauterine device usage

Usage of

A double uterus is the normal female anatomy in many