How long does it take to drink special milk powder for premature infants?

Premature infants if breast-feeding, can choose preterm infants dedicated milk powder feeding, which contains minerals, trace elements and other nutrients, it can supplement premature infants after birth deficiency, to meet the growth needs of premature infants. Premature infants drink milk powder generally drink to correct the baby's gestational age 40 weeks later, you can change to ordinary milk powder to drink.