This document discusses short cervix and cervical insufficiency. It defines a short cervix as a cervical length of 10-20mm or less than 25mm measured between 18-24 weeks gestation. Women with a cervix under 15mm before 24 weeks need cervical cerclage placement. Cervical length is best measured via transvaginal ultrasound. Risk factors for cervical insufficiency include DES exposure, uterine anomalies, history of second trimester losses, cervical lacerations or multiple terminations. Management may include cervical cerclage placement before 24 weeks for those with two or more third trimester losses. Health education on cervical changes is also important.