We report a new case with favorable outcome of Herlyn-Werner-Wunderlich syndrome coexisting with pyocolpos due to Actinomyces infection, diagnosed during pregnancy. Together with cases reported in the literature, it suggests that early excision of the vaginal septum and adequate drainage can shorten course of treatment and avoid unnecessary complications. Herlyn-Werner-Wunderlich syndrome (HWWS) is a rare congenital malformation characterized by a triad of uterine didelphys, obstructed hemivagina, and ipsilateral renal agenesis. It is also known as OHVIRA syndrome (obstructed hemivagina, ipsilateral renal anomaly) which has gained popularity due to the report of cases with a nondidelphys uterus. 1,2 The incidence of HWWS/OHVIRA syndrome is the rarest type of Müllerian duct anomalies (MDAs), accounting for 0.1-3.8% of all MDAs of which its incidence is estimated to be 4.3-6.7%. 1,3,4 The HWWS was first described by Purslow (1922) and Embrey (1950) and became more popular in 1970s following the descriptions by Herlyn and Werner, and Wunderlich. 1,2,5 Didelphys uterus is a result of fusion arrest of the Müllerian ducts which should derive to uterus and cervix, whereas maldevelopment of the Wolffian ducts leads to abnormalities of kidneys and ureters. 1 The onset of symptoms of HWWS usually occurs in the teenage years, shortly after menarche. Common presenting symptoms of HWWS are progressive cyclic pelvic pain

Objective: To compare the cervical shear wave elastography (SWE) by using transvaginal ultrasound (TVS) between twin and singleton pregnant women. Materials and Methods: This was a prospective cohort study involving the twin and singleton pregnant women who attended the antenatal care at