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What is On Transvaginal Sonography (TVS) which of the following shapes of cervix indicate imminent preterm labour? and explain in detail?
On ultrasound examination, normal cervix is T shaped. As the internal cervical os opens and the membrane stas herniating to the upper pa of endocervical canal, the cervical shape on ultrasound changes to a Y. With fuher progression of cervical changes, Y shape changes to V and ultimately to U. Thus, U shaped cervix on transvaginal sonography indicate imminent preterm labour. Ref: Textbook of Obstetrics By D. C Dutta, 6th Edition, Page 315; SOAP For Obstetrics And Gynecology By Peter S. Uzelac Page 50; Tips and Tricks in Operative Obstetrics and Gynecology By Richa Saxena Page 221.