A rare dichorionic triamniotic triplet pregnancy with spontaneous twin anemia-polycythemia sequence between two dichorionic fetuses

IntroductionThis report presents a rare case of spontaneous twin anemia-polycythemia sequence (TAPS) between two dichorionic fetuses in a spontaneous, homozygotic, dichorionic, triamniotic, triplet pregnancy treated with multiple intrauterine blood transfusions and partial exchange transfusions. Case presentationThe pregnancy was diagnosed with stage IV TAPS at gestational week 25+1. The patient was treated with laser surgery combined with multiple intrauterine blood transfusions and partial exchange transfusions. The triplets were delivered at a planned caesarean section at gestational week 28+1 with postnatal hemoglobin values of 18.21, 26.43 and 11.92 g/dl in triplet 1, 2 and 3, respectively. At four years of age triplet 1 is considered healthy, triplet 2 is diagnosed with mild mental retardation, and triplet 3 with profound mental retardation and dystonic cerebral palsy. Discussion/conclusionThis is an extremely rare case of TAPS between dichorionic fetuses in a triplet pregnancy and routine surveillance with measurement of MCA-PSV in dichorionic pregnancies may contribute to the detection of similar cases in the future. Furthermore, this case contributes with rare long-term follow-up data of children treated for high stage TAPS with multiple IUTs and PETs.