Which is not true about the indication of exchange transfusion? (Not a criteria for exchange transfusion)

Double volume exchange transfusion (DVET) should be performed if the total serum bilirubin(TSB) levels reach to age-specific cut off for the same. For < 28 wk gestation, TSB cut off is 11-14 mg/dl. For 28 to 29 wks, 30 to 31 wks and 32 to 33gestation, cut off is 12-14, 13 - 16 and 15-18 mg/dl respectively. For 34 wks of gestation, cut off is 17-19 mg /dl.