Bicornuate pregnancy

Clinical History

26-year-old primigravida with vaginal bleeding for the past four days. No history of passing clots or products of conception. The patient had minimal lower abdominal pain.

Imaging Findings

On sonography there were two myometrial echoes and two separated endometrial echoes. 8-7cm; 8-9 cm; 2-3cm. There was a live gestation corresponding to 11 weeks and 3 days in the left horn. Foetal cardiac activity was normal. Foetal active movements were present. The right horn showed decidual reaction. Cervix appeared to be single. Both ovaries were normal.

Discussion

Bicornuate uterus belongs to the Class IV type of mullerian duct anomalies according to the AFS classification system. The fused caudal end of the mullerian duct forms the Uterus, Cervix and the Vagina.The unfused cephalad portion forms the fallopian tubes. The fusion occurs in the cephalad direction. The median septum formed by the medial walls of the mullerian duct resorbs leaving a single uterine cavity. A bicornuate uterus results from partial nonfusion of the müllerian ducts. The central myometrium may extend to the level of the internal cervical os (bicornuate unicollis) or external cervical os (bicornuate bicollis). The latter is distinguished from didelphys uterus because it demonstrates some degree of fusion between the two horns, while in classic didelphys uterus, the two horns and cervices are separated completely. In addition, the horns of the bicornuate uteri are not fully developed; typically, they are smaller than those of didelphys uteri. US may demonstrate two uterine cavities with normal endometrium. The most important imaging finding is a concave fundus with a fundal cleft greater than 1 cm. This has been shown to be a reliable mean of distinguishing UTERUS BICORNIS UNICORNIS. 3D US may play a useful role in making this diagnosis. An increased intercornual distance (>4 cm) may be observed. The cleft is visualized best on oblique coronal images in the plane of the long axis of the uterus. The septum separating the two horns demonstrates echogenicity identical to myometrium. The inferior portion of the septum (extending for a variable length inferiorly) may be fibrous. The BICORNUATE UNICOLLIS UTERUS is associated with increased incidence of spontaneous abortions and obstetrics complications.

Differential Diagnosis List

Final Diagnosis

BICORNUATE PREGNANCY

URL:	https://www.eurorad.org/case/5700
DOI:	10.1594/EURORAD/CASE.5700
ISSN:	1563-4086