Inclusion Criteria:  Singleton pregnancy at 23+0 - 33+6 weeks' gestation Age > 18 years old Patients should be capable of providing consent to participate in the study  Exclusion Criteria:  Previous spontaneous preterm (20+0 - 36+6 weeks' gestation) delivery (including history of pregnancy loss due to cervical incompetence, i.e painless cervical dilatation prior to 24 weeks' gestation) Treatment with 17 hydroxyprogesterone caproate due to a previous spontaneous preterm delivery Detection of a cervical length < 25 mm during routine ultrasound < 24 weeks' gestation in asymptomatic patients (i.e patients that do not complain of uterine contractions or patients with no uterine contractions documented on tocometry) Treatment with vaginal progesterone or micronized progesterone due to a cervical length < 25 mm Cerclace placement in the current or in a previous pregnancy Multiple pregnancy Age < 18 years old Preterm premature rupture of membranes (pPROM) upon initial presentation Müllerian malformations Prior cervical surgery