Are Cervical Length and Fibronectin Predictors of Preterm Birth after Fetal Spina Bifida Repair? A Single Center Cohort Study

Background: A remaining risk of fetal spina bifida (fSB) repair is preterm delivery. This study assessed the value of preoperative cervical length (CL), CL dynamics (∆CL) and fetal fibronectin (fFN) tests to predict obstetric complications and length of stay (LOS) around fSB repair. Methods: 134 patients were included in this study. All patients had CL measurement and fFN testing before fSB repair. ∆CL within the first 14 days after intervention and until discharge after fSB repair were compared in groups (∆CL ≥ 10 mm/<10 mm; ≥20 mm/<20 mm). CL before surgery, ∆CL’s, and positive fFN tests were correlated to obstetric complications and LOS. Results: Mean CL before surgery was 41 ± 7 mm. Mean GA at birth was 35.4 ± 2.2 weeks. In the group of ∆CL ≥ 10 mm within the first 14 days after intervention, LOS was significantly longer (p = 0.02). ∆CL ≥ 10 mm until discharge after fSB was associated with a significantly higher rate of GA at birth <34 weeks (p = 0.03). The 3 positive fFN tests before fSB repair showed no correlation with GA at birth. Conclusion: Perioperative ∆CL influences LOS after fetal surgery. ∆CL ≥ 10 mm until discharge after fSB repair has a 3-times higher rate of preterm delivery before 34 weeks. Preoperative fFN testing showed no predictive value for preterm birth after fSB repair and was stopped.