Abstract: Premature delivery is the main cause of neonatal morbidity and mortality，and cervical incompetence is one of the major reasons that caused the late miscarriage and premature birth. Cervical incompetence is also called cervical insufficiency，it means that after pregnancy, before reaching full-term pregnancy, cervical performance flattening, thinning, cervical tube expansion or become wider, eventually led to the medium-term pregnancy abortion or premature birth. In Europe and other developing countries, reported preterm birth rates are around 5%-9% and this appears to have increased in some countries. Few interventions have improved outcome, and management remains an important challenge in modern obstetrics. Cervical cerclage is a common prophylactic intervention performed by obstetricians in the management of women with second-trimester losses or preterm deliveries, despite the lack of a well-defined population for whom there is clear evidence of benefit. The efficacy of cerclage is uncertain. In this paper, we will evaluation the cervical function and cervical cerclage indications in the second trimester of pregnancy.

Key words: Premature birth, Uterine cervical incompetence, Cerclage, cervical