Proximate Cord Insertion in Twin-to-Twin Transfusion Syndrome: Case Series and PRISMA Compliant Systematic Review and Meta-Analysis.

OBJECTIVE

We aimed to investigate the prevalence and clinical outcomes of twin-to-twin transfusion syndrome (TTTS) with proximate cord insertions.

METHODS

This was retrospective cohort study of TTTS cases managed at single fetal center between 2012 and 2020. Presence of proximate cord insertions was defined as a distance of equal or less than 4 cm between placental cord insertions that was recorded based on sonographic and fetoscopic examinations. Clinical outcomes were investigated compared to unmatched cohort and to 1:2 matched controls using preoperative variables including Quintero staging, selective fetal growth restriction, anterior placenta, preoperative cervical length, and gestational age at fetal intervention. Systematic review and meta-analysis were conducted following PRSMA guidelines through searching PubMed, Scopus, CINAHL, and Medline databases from inception until January 2021.

RESULTS

The prevalence of proximate cord insertions in monochorionic placentas with TTTS was 2% (5/246). All 5 cases were managed by fetoscopic laser surgery (FLS). Procedure time was significantly longer (mean: 61.4 min in proximate cord vs. 37.5 min in nonproximate cord, p < 0.001), and amnioinfusion was significantly more common (100% in proximate cord vs. 43% in nonproximate cord, p = 0.01). Perinatal survival and neonatal outcomes were not different between groups. Similar findings were seen following 1:2 control matching. Systematic review yielded total of 19 case reports of which different management options were applied including FLS (n = 13), amniodrainage (n = 3), and selective reduction (n = 3). Clinical outcomes results were mixed and inconsistent. FLS was described as technically challenging and residual anastomosis was common. Overall fetal and neonatal survival following FLS was 85% and 80%, respectively.

CONCLUSION

Presence of proximate cords in TTTS cases poses serious technical challenges even for highly experienced surgeons. Feasibility should be only determined by fetoscopic examination.