The case presentation of a transvaginal cervical cerclage performed at a 7 cm dilation in a patient in the 22nd week of pregnancy, followed by a prolongation of the pregnancy until the gestational age of 38 weeks, was reported in the context of many similar cases managed by the authors of the article during a program of screening and prevention of preterm birth. The particularity of the case was the lack of a preterm birth in the medical history of the patient and the installation of the isthmus-cervix incompetence in the second pregnancy, after an on term pregnancy. What should be evidenced is the importance transvaginal cervical ultrasound evaluation has in the early diagnosis of this pathology during pregnancy, this being the only method of determining the efficacy of the content of the internal cervical os. Transvaginal cervical exploration has to be implemented as a screening method both in the high-risk patients and in the absence of a suggestive medical history.