Various Types of Niche Imaging by Sonohysterography

Cesarean scar defects (CSD) or niche are the myometrial discontinuity at the previous cesarean section scar region. We aimed to depict various types of niche imaging by sonohysterography. Recently, the rate of cesarean section delivery has markedly risen around the world; therefore, women with cesarean scar defects are increased and present in up to 19% of women post cesarean section. The increase of repeat cesarean section has been associated with an increase in complications in subsequent pregnancies such as scar pregnancy with life threatening bleeding, uterus rupture, placenta accreta and its subtypes and prolonged postmenstrual spotting. The deeper the niche (or the thinner the overlying myometrium), the higher the risk for complications in a subsequent pregnancy. Various shapes of uterine cesarean scar defects (niche) in TVS and SHG include: thin linear defect, wedge shape defect, droplet defect, semicircular defect, rectangle defect, inclusion cyst defect, irregular defect, multiple defects. Although the ability of transvaginal ultrasound (TVUS) to detect cesarean scars remains unknown, its higher frequency and proximity to the pelvic organs has been used as a powerful tool for detecting the uterine scar of a previous cesarean section. Recently with the increasing use of sonohysterography (SHG) (transvaginal ultrasound with saline infusion) detection of scar defect has been enhanced frequently.