Twin pregnancy is fundamentally a preterm birth condition, yet not all cervical shortening represents the same biological process. This talk explores a contemporary, phenotype-based approach to cervical length screening in twin pregnancies, moving beyond a simple “short versus normal” framework. Through the identification of three distinct cervical phenotypes, normal cervix, short cervix, and cervical dilation, the presentation examines how risk stratification can guide surveillance and intervention. Evidence for vaginal progesterone, cervical cerclage, and Arabin pessary will be critically reviewed, with emphasis on emerging data, biological plausibility, and pragmatic clinical decision-making in contemporary twin care.