Twin-to-Twin Transfusion Syndrome in a Dichorionic Diamniotic Pregnancy with Unusual Ultrasound Findings

Abstract Introduction/Objective Twin-to-twin transfusion syndrome (TTTS) is a complication of twin gestations which affects approximately 1-3 per 10,000 births and is most commonly observed in monochorionic diamniotic twins. The authors present a rare case of TTTS occurring in dichorionic diamniotic twins and literature review. Methods/Case Report The patient was initially found to have a twin pregnancy at 12 weeks of gestation with ultrasound findings suggestive of monochorionic diamniotic twins, but subsequent ultrasounds demonstrated a twin- peak sign, indicating a dichorionic diamniotic gestation. Her pregnancy was subsequently complicated by the discovery of TTTS at 26 weeks of gestation leading to her hospitalization for inpatient fetal surveillance and amnioreduction. She was discharged in stable condition. However, despite close follow-up, there was ultimately intrauterine demise of Twin B (donor twin) at 30 weeks and 6 days gestational age. There were no other complications during the course of pregnancy. Examination of the placenta at autopsy was consistent with a dichorionic diamniotic pregnancy with anastomoses within the fused placenta and evidence of prolonged oligohydramnios by presence of amnion nodosum, supporting the clinical and sonographic findings of TTTS. Results (if a Case Study enter NA) NA Conclusion In summary, this is a rare case of TTTS occurring in a dichorionic diamniotic twin gestation with clinical, sonographic, and pathologic findings. Only five cases have been reported thus far in the literature.