Study question: What are the anatomic variants (and their frequencies) of double uterus, obstructed hemivagina and ipsilateral renal agenesis?

Summary answer: Most cases examined (72.4%) were of the classic anatomic variant of the Herlyn-Werner-Wunderlich syndrome (with didelphys uterus, obstructed hemivagina and ipsilateral renal agenesis) but the 27.6% of cases are of a rare variant of the syndrome (with uterus septum or cervical agenesis), showing relevant clinical and surgical implications.

What is known already: The extreme variability of anatomic structures involved in this syndrome (both uterus, cervico-vaginal and renal anomalies) is well known, even if a complete and uniform analysis of all its heterogeneous presentations in a large series is lacking.

Study design, size, duration: This is a retrospective study with 87 patients referred to our third level referral center between 1981 and 2011.

Participants/materials, setting, methods: We analyzed the laparoscopic and chart records of 87 women, who referred to our institute with double uterus, unilateral cervico-vaginal obstruction and ipsilateral renal anomalies.

Main results: Sixty-three of 87 patients had the more classic variant of didelphys uterus with obstructed hemivagina; 10/87 patients had septate bicollis uterus with obstructed hemivagina; 9/87 patients had bicornuate bicollis uterus with obstructed hemivagina; 4/87 patients had didelphys uterus with unilateral cervical atresia; 1/87 patients had bicornuate uterus with one septate cervix and unilateral obstructed hemivagina.

Limitations: This is a retrospective study with a long enrolling period (30 years).

Wider implications of the findings: New insights in the anatomic variants of this rare syndrome with their relevant surgical implications.