Hemodynamic adaptation in complicated monochorionic twin pregnancies

Monochorionc twin pregnancies carry a high risk for adverse pregnancy outcome. The unique placenta angioarchitecture in monochorionic twin pregnancies might cause specific complications such as twin-to-twin transfusion syndrome (TTTS) and selective intrauterine growth restriction (sIUGR). The hemodynamic challenges in these complications require specific adaptation of the fetal heart. Subsequently, a higher risk for fetal demise and acquired cardiac abnormalities is present in these cases.In part one of this thesis we focused on the risk for fetal demise. We investigated possible predictors for fetal demise after laser therapy for TTTS, and found that abnormal Doppler profiles and the presence and absence of certain anastomoses are associated with this complication. Beside this, we investigated the possible relation between proximate cord insertion and fetal deterioration.In part two we investigated possible predictors for the development of right ventricular outflow tract obstruction (RVOTO), and found that an early gestational age at onset of TTTS and cardiac dysfunction are associated with this complication. We described that postnatal RVOTO is not only found in recipients, but also in donors and sIUGR cases. We described the spectrum of prenatal RVOTO in relation to postnatal RVOTO. Lastly we introduced a new modality to detect fetal cardiac dysfunction.