Neonatal outcome in monochorionic twins with twin-to-twin transfusion syndrome following intrauterine treatment with amnioreduction or fetoscopic laser surgery: Comparison with dichorionic twins matched for gestational age


      Monochorionic pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) are at increased risk for prematurity but also for more specific causes of perinatal mortality and morbidity, mainly related to inter-twin hemodynamic imbalance. This study was undertaken to compare neonatal outcomes in TTTS infants and in dichorionic (DC) twins in relation with intrauterine treatment and controlling for prematurity.

      Study design

      Case-control study carried out between 2000-2005. Neonatal outcome was assessed in 133 TTTS preterm infants treated in utero with either serial amnioreduction (n=36) or fetoscopic laser placental surgery (FLPS) (n=97) and delivered at 24-34 weeks of gestation. Both groups were matched for gestational age with two different control groups of DC twins because gestational age at birth was different in amnioreduction (28.9±2.6) and in FLPS (30.1±3.2 weeks) cases (p=0.02).


      Perinatal survival was significantly lower in TTTS infants treated by amnioreduction (52% vs 83%, p=0.003) and neonatal neuromorbidity (cystic periventrcular leukomalacia : 25% vs 5.6%, p=0.009) was higher than in DC controls. However, the incidence of perinatal mortality (11.3% vs 12.4%) and of severe cerebral morbidity (17.9% vs 12.9%) were similar in TTTS infants treated by FLPS and in DC controls. Logistic regression analysis showed that gestational age was the only significant factor associated with adverse neonatal outcome in infants born after FLPS in utero and in their DC controls.


      Neonatal mortality and morbidity in TTTS preterm infants treated by FLPS in utero were not different from those of DC infants matched for gestational age at birth. Perinatal outcome is poorer in TTTS infants following amnioreduction than in DC controls. These results support that placental surgery contributes to functionally dichorionize the placenta in TTTS.