Third trimester fetoscopic laser ablation therapy for type II vasa previa

Fetoscopic laser ablation is a new treatment for type II vasa previa (VP). Benefits include avoidance of hospitalization and opportunity for a term vaginal delivery. The potential risks of fetoscopy can be mitigated by delaying laser surgery to a gestational age (GA) of 31-32 weeks, prior to anticipated hospitalization. The aim of this study was to assess feasibility and outcomes of type II VP patients treated via fetoscopic laser ablation in the third trimester. This is a retrospective study of singleton pregnancies with type II (includes type III) VP treated with laser at >31 weeks GA at our center between 2006-2022. Newborn outcomes were assessed. Continuous variables are expressed as mean ± standard deviation. 74 patients were referred with VP, and 23 (31%) underwent laser ablation. Of the 51 remaining cases, 21 had type I VP (laser contraindicated), 18 either had no or resolved VP, and 12 had type II VP but declined laser surgery. Of the 23 laser cases, 6 (4 twin gestations, 2 laser cases before third trimester) were excluded, leaving 17 study patients. The mean GA at procedure was 32.0 ± 0.6 weeks and total operative time was 62.1 ± 19.6 minutes. There were no perioperative complications. All cases had successful occlusion of the VP (1 case required a second procedure). All patients were subsequently managed as outpatients. The mean delivery GA was 37.2 ± 1.8 weeks, 65% delivered vaginally, and mean birthweight was 2817 ± 487 grams. Neonatal intensive care unit admission was required in 3 cases: 1 case of respiratory distress syndrome, 2 cases of hyperbilirubinemia with phototherapy; there were no cases of neonatal transfusion, intraventricular hemorrhage, sepsis, patent ductus arteriosus, or deaths. This cohort represents the largest number of type II VP cases treated via laser reported to date. Laser occlusion of type II VP at 31-32 gestational weeks was technically achievable and resulted in favorable outcomes.