“…In the present study, a different frequency of VVC (39.76%) was reported when compared to our previous studies in Ahvaz in 2016 (28.3%) and 2010 (49%) (15,21). The frequency of VVC in other cities in Iran was reported as 62.1%, 43.3%, 40%, 26%, and 4.8% from Ilam, Babol, Arak, Hamadan, and Zanjan, respectively (12,13,16,31,32).…”