Peri-operative prognostic factors in twin-to-twin transfusion syndrome treated by fetoscopic laser occlusion of chorionic plate anastomoses

Abstract

To describe peri-operative prognostic factors of survival without impairment in twin-to-twin transfusion syndrome (TTTS) treated by fetoscopic laser occlusion of chorionic plate anastomoses. Monochorionic pregnancies complicated with severe TTTS and treated by fetoscopic laser surgery were reviewed between 1999 and 2005. Peri-operative factors studied included maternal characteristics, severity of the fetal syndrome and characteristics of surgical procedures and were collected prospectively but analysed retrospectively. Primary outcome was survival >28 days of at least one twin without severe impairment. Univariate and multivariate analyses using logistic regression were conducted. 10 of a total of 323 cases were lost to follow-up and excluded from analysis. Median gestational age at diagnosis (25th, 75th percentile) was 21 (19, 23) weeks of gestation. Distribution across Quintero stages was: 17.4%, 40.2%, 37.3% and 5.1% for stages 1, 2, 3 and 4 respectively. Overall survival rate of at least one twin without severe impairment was 65%. Significant factors found in univariate analysis were donor and recipient estimated weight at diagnosis (p=0.02, OR=1.77 [1.07-2.96] and p=0.001, OR=2.12 [1.27-3.59] respectively), discordant growth (p=0.04, OR=1.66 [1.01-2.77]), number (≥4 vessels) and proportion (≥60% of all coagulations) of selective coagulations ((p=0.01, OR=1.81 [1.11-2.99]) and (p=0.02, OR=1.77 [1.08-2.92]) respectively) as well as amniotic fluid volume ≥1 litre drained (p=0.001, OR=2.18 [1.26-3.79]). Multivariate analysis showed that only the recipient's estimated weight at diagnosis and selective coagulations ≥4 during the procedure were significantly predictive of survival (p=0.002, OR=2.20 [1.34-3.63] and p=0.001, OR=1.89 [1.17-3.07] respectively). In severe TTTS treated by fetoscopic laser occlusion of chorionic plate anastomoses, peri-operative prognosis is based upon estimated fetal weight at diagnosis and selectivity of the procedure.