✔️Mid-trimester cervical length (CL) assessment by transvaginal (TV) ultrasound is the best clinical predictor of spontaneous PTB.➡️Depending on the population studied and the gestational age of assessment, the threshold chosen in clinical practice as “short” ranges from 20 to 30 mm.✔️The risk of spontaneous PTB is inversely proportional to the CL.➡️Those with the shortest CL have the highest risk of prematurity.✔️TV ultrasound is considered the ‘gold standard’ measurement when assessing CL. ➡️I