sir, we have a 36 days baby preterm (32 weeks/twin)born by IVF surrogate mother ,initially on top feed suddenly had vomitings bilious,baby was kept NPO presuming preterm NEC xray abbomen were done and USG done which were normal and the baby passed stool next morning normal ,baby had edema of lower limbs ,septic screen normal,urine analysis,cardiac normal,KFT,ABG normal hemogram showed low Hb-9 rest normal 15ml packed cells transfused and little edema subsided then again developed edema of B/L lower limbs,current Hb is 10.9 gms,wt:1.368 kgs ,please let me know the cause and further treatment. regards dr.vivek sharma