Background – The value of transvaginal cervical length surveillance for predicting spontaneous preterm birth (sPTB) in women with congenital uterine anomalies (CUA) is unclear. Objective - A systematic review and diagnostic accuracy meta-analysis of cervical length surveillance for predicting sPTB in women with CUA Search strategy – A literature review of MEDLINE, EMBASE, and the Cochrane Library from inception to December 2025. Selection criteria - Observational studies evaluating 2 nd trimester cervical length measurement in pregnant women with CUAs. Data collection and analysis - Review Manager and Meta-DiSc, with pooled odds ratios (ORs), sensitivity, specificity, likelihood ratios, and SROC curves generated using a random-effects model. Results – 5 studies including 624 women met the inclusion criteria. sPTB occurred in 52% with a short cervix versus 13.2% with normal cervical length (OR 8.05, [4.52–14.35]). A short cervix increased the risk of sPTB before 37 weeks (OR 6.68, [3.68–12.11]) and before 35 weeks (OR 28.16, [5.64–140.48]). The association was strongest for bicornuate uterus (OR 40.98, [4.27–393.10]), though estimates were imprecise. At a 25-mm cervical length threshold, sensitivity was low (0.35, [0.23 - 0.49]), specificity was high (0.94, [0.91 - 0.96]), with a LR+ ratio of 5.51. A 30 mm threshold improved sensitivity (1.00, [0 – 1.00]) but reduced specificity (0.84, [0.67 - 0.94]), reflecting sparse data. The SROC curve indicated moderate-to-good discriminatory performance. Conclusion – Cervical length measurement yields clinically useful risk stratification, especially when a short cervix is present. At the conventional 25-mm threshold, high specificity but limited sensitivity makes it better for confirming than excluding risk. Higher thresholds may improve detection, but the optimal cut-offs are still uncertain.