N-terminal pro-brain natriuretic peptide levels in monochorionic diamniotic twins with twin-to-twin transfusion syndrome treated by fetoscopic laser photocoagulation.

Twin-to-twin transfusion syndrome (TTTS) affects 15% of monochorionic diamniotic (MD) twin pregnancies, and is associated with adverse perinatal outcome. Recently, fetoscopic laser photocoagulation (FLP) has been widely accepted as the most definitive therapy to treat TTTS. N-terminal pro-brain natriuretic peptide (NT-proBNP) is a powerful diagnostic marker of cardiac dysfunction in neonates, and is elevated in MD twins with TTTS. However, there are no reports assessing the effect of FLP on neonatal cardiac overload in TTTS by measuring the serum NT-proBNP levels at birth. Here, we aimed to compare serum NT-proBNP levels at birth in MD twins with TTTS treated with FLP or not. Twelve MD twin pairs with TTTS admitted to our center between October 2007 and September 2012 were enrolled in this study. The MD twin pairs were separated into two groups: seven twins (12 newborn infants) with FLP (FLP group) and five twins (nine newborn infants) without FLP (non-FLP group). Gestational age, birthweight, and Apgar scores were significantly higher in the FLP group than that in the non-FLP group. Serum NT-proBNP levels at birth were significantly lower in the FLP group than in the non-FLP group [1425 pg/ml (range, 466-9560) vs. 29900 pg/ml (range, 7300-77900), respectively; p=0.0003]. The serum NT-proBNP levels of larger and smaller co-twins were significantly correlated with each other (r=0.750; p=0.026). In conclusion, serum NT-proBNP levels at birth are lower in MD twins with TTTS after FLP treatment than in those without FLP.