neonatal anemia immune system disorder twin to twin transfusion syndrome https://www.malacards.org/card/twin_to_twin_transfusion_syndrome foetal blood loss from foetal haemorrhage into co-twin TTTS placental transfusion syndrome SCTID:13404009 Feto-fetal transfusion syndrome NCIT:C113824 MedDRA:10058328 icd11.foundation:850604370 NORD:2021 MEDGEN:777055 stuck Twin syndrome Fetofetal transfusion syndrome fetal transfusion syndrome foetal haemorrhage into co-twin Twin twin transfusion syndrome (TTTS) is a rare condition seen in twin monochorionic pregnancies, typically developing during the 15-26 week gestation period and usually due to unbalanced intertwin placental anastomoses, where an unequal exchange of blood between twins causes oligohydramnios in one sac and polyhydramnios in the other which can lead to a high perinatal mortality rate and a high rate of disability in survivors if left untreated MESH:D005330 Twin Anemia Polycythemia Sequence DOID:13576 GARD:0000325 foetal transfusion syndrome Twin-Twin transfusion syndrome twin-to-twin transfusion syndrome MONDO:0019805 UMLS:C2909036 Orphanet:95431 EFO:1001221