Risk of Cord Entanglement After Iatrogenic Monoamnionicity, With Selective and Solomon Laser Treatment for Twin-To-Twin Transfusion Syndrome in Monochorionic Twin Pregnancies.

Introduction: Fetoscopic laser surgery (FLS) is the gold standard treatment for monochorionic (MC) twin pregnancies complicated by twin-twin transfusion syndrome (TTTS). The aim of our study was to evaluate the rate and risk factors for cord entanglement in the presence of iatrogenic monoamnioticity (iMA), a consequence of inadvertent septostomy during FLS.

Methods: This is a retrospective analysis of two consecutive cohorts of FLS performed either using the selective technique from January 2004 to January 2012, or with the Solomon technique, from that date onwards. Maternal and fetal characteristics, technical details, and obstetrical and perinatal outcomes were recorded. Cord entanglement was identified based on the presence of a galloping sign observed during prenatal ultrasound in the presence of iMA. At our center, mono-amniotic twins are electively delivered at 32 completed weeks.

Results: The mean gestational age of the 558 FLS, 52.3% selective and 47.6% Solomon, was 19.8 weeks (15.1-26.4). Solomon laser coagulation was associated with a lower occurrence of TAPS or TTTS (5.3% vs. 13%, p = 0.001) after the FLS and a higher number of placental abruption (9% vs. 2% p < 0.001) and by more cord entanglement in the presence of iMA (9.4% vs. 2.4% respectively, p < 0.001). The presence of iMA was correlated with a higher occurrence of limb defects (6.2% vs. 1% in non-iMA twins, p 0.001).

Conclusions: Solomon FLS was associated with a higher risk of cord entanglement and placental abruptio. As a consequence, we delivered twins with iMA earlier.