Fetal cardiac collapse diagnosed by umbilical venous flow volume after thoraco-amniotic shunting for severe pleural effusion

Objective: Although thoraco-amniotic shunting (TAS) for severe pleural- effusion is an effective fetal treatment, there are some cases in which deteriorates showing circulatory collapse. To evaluate usefulness of umbilical venous blood flow volume (UVFV) for predicting deterioration, we analyzed fetal low UVFV situation. Methods :In 22 cases of fetal severe pleural effusion, we measured UVFV/fetal estimated birth weight (ml/min/kg) prospectively before and after TAS by ultrasonography. We defined low UVFV/kg as <50 ml/min/kg (2.5 percentile) and compared subgroups based on their UVFV value and analyzed the outcome after birth. Results: Total survival rate was 59% at 6 months. Seven cases in the low group before delivery (UVFV/kg 19.5) showed poor prognoses such as fetal/neonatal death and longer neonatal intensive care unit management (100% v.s. normal UVFV group 40%,p=0.017). The low group also showed umbilical artery absent end-diastolic velocity (71%); edema resolved in 50%, suggesting hypo inflow from the placenta and fetal hypo-cardiac output status revealing fetal cardiac collapse. Conclusions: UVFV analyses would be new marker of fetal management of severe pleural effusion suggesting low UVFV after TAS seems to be hypovolemic cardiac collapse and showed poor prognosis and we had better consider immediate delivery preventing death even after TAS.