Introduction: Preterm birth is considered a worldwide problem having multifactorial causes showing a high rate of morbidity and mortality, even in this 21st century; researchers are working in the proteomics field searching for new solutions to its prophylaxis. Objective: This article is aimed at reaching a review of the most recent aspects concerning the use of progesterone to the specialists who follow up pregnant women having short cervix and history of preterm births. Development: A transvaginal cervicometry is performed in the 18th and 24th weeks of gestation, which can also be performed trans-abdominally to determine the length of cervix, the internal cervical os(ICO), the existence or not of cervical funneling, the presence of complete, partial or non-presence of mucous plug, and if sludge is observed in the amniotic fluid or the socalled muddy fluid; in this case, a cervix length lesser than 25 millimeters, in a single pregnancy, helps us to predict a high risk of preterm birth, worsening if the other factors mentioned before are observed; which can be previously explored using this technique. Henceforth, considering these results and evidences, the treatment with progesterone can be established following the recommended scheme. Conclusions: The cervicometry and the assessment of other factors in the cervix, together with the evidences found aid establishing prophylactic measures to avoid preterm births using progestins.