Preoperative Amniotic Fluid Interleukin-6 Levels as Predictors of Adverse Perinatal Outcomes following Fetal Laser Surgery for Monochorionic Twin Complications

INTRODUCTION: This study aimed to assess whether levels of interleukin 6 (IL-6) in amniotic fluid (AF) can predict perinatal complications following fetal laser surgery in monochorionic twins with twin-to-twin transfusion syndrome (TTTS). METHODS: We conducted a retrospective cohort study at the Fetal Medicine Center from 2013 to 2024, analyzing AF samples from 152 monochorionic twin pregnancies prior to surgery. Cutoff levels for IL-6 were set at 400 ng/L and 2,000 ng/L based on a 10% false-positive and -negative rate. RESULTS: Among the 152 women who underwent laser surgery, significant associations were found between AF IL-6 levels and pregnancy duration in TTTS cases (p = 0.005); in cases complicated by selective growth restriction, no significant association was found (p = 0.584). Overall, 112 TTTS pregnancies were categorized into 3 groups according to IL-6 levels. The overall prevalence of short surgery-delivery interval (<14 days) was 11.6% (13/112), 1.9% in the low-risk group, and 21.4% in the high-risk group (OR 13.9, p = 0.028). The risk of preterm birth (≤28 weeks) was also higher in the high-risk group (50% vs. 9.6%, OR 9.4, p = 0.002), and adverse neonatal outcomes were more prevalent (63.6% vs. 20%, OR 7.0, p = 0.007). CONCLUSION: AF IL-6 levels are a reliable marker for predicting adverse perinatal outcomes after fetal laser surgery, showing a high negative predictive value.