Invasive fetal therapy Invasive fetal therapy in Sweden consists of fetoscopic interventions to treat twin-to-twin transfusion syndrome (TTS) or twin anemia polycytemia sequence (TAPS) in monochorionic twin or triplet pregnancies and for selective reduction in monochorionic twins complicated by discordant anomalies or severe growth retardation in one fetus. Alternative methods, such as intrafetal laser ablation and radio frequency ablation, are also used for selective reduction and rarely to treat fetal tumors. Ultrasound guided intrauterine blood transfusions to treat fetal anemia have been performed for a long time with excellent results. Placement of thoraco-amniotic shunts and vesico-amniotic shunts is indicated in a few cases per year in Sweden. Since these rare interventions were centralized to one national center in 2013, the outcome of the fetal interventions has improved consistently.