In this case, the uterus is bicornuate bicollis (complete division), with one horn containing a viable normal pregnancy with its own placenta, and other horn containing a non-viable monochorionic diamniotic twin pregnancy.

The woman had previous delivery by CS where she was notified by her obstetrician that she had a uterine anomaly. She came to our department this current pregnancy, with the early ultrasound scan showing triplet pregnancy in a divided uterine cavity by 2D ultrasound.

According to the Müllerian duct anomaly classification which is a seven-class system, this case is class IV (bicornuate uterus), sub-classified to (a) which is  complete division, all the way down to the external os (bicornuate bicollis), as shown in the last image.

The cervical length was about 4 cm, and she was counseled that there was no indication for cervical cerclage.