We investigated pregnancy outcome following transabdominal cerclage (TAC) in women with cervical insufficiency (CI) and explored parameters for predicting pregnancy outcomes following TAC. In this retrospective cohort study, we included 161 women with TAC. We considered demographic, obstetric, and gynecologic histories, pre- and postoperative cervical length (CL), and CL at 20-24 weeks as parameters for predicting outcomes following TAC. Univariate and multivariate analyses were used to identify risk factors for predicting delivery before 34 weeks after TAC. 182 pregnancies occurred after TAC, and 290 pregnancies prior to TAC were identified. The rate of delivery <34 weeks significantly decreased following TAC (5% versus 82%, P < 0.001). Univariate analysis demonstrated that a short CL (<25 mm) at 20-24 weeks and adenomyosis were associated with delivery at <34 weeks' gestation following TAC (P = 0.015 and P = 0.005, resp.). However, multivariate analysis demonstrated that only a short CL (<25 mm) at 20-24 weeks was a significant predictor (P = 0.005). TAC is an efficacious procedure that prolongs pregnancy in women with CI. A short CL at 20-24 weeks may predict the delivery at <34 weeks' gestation following TAC.