**Transition From Donor Milk: A Feasibility Study** This study is for babies born too early (preterm) and weighing very little (less than 1,500 grams). These babies often get donor human milk (DHM) to help them grow. The study wants to see if switching from DHM to a special formula for preterm babies after one month is safe and helps them grow better. *Eligibility*: Babies must weigh more than 1,250 grams, be at least 28 days old, and be fed with DHM (with or without their mother's milk). Some babies cannot join, like those with birth weight below the 5th percentile or certain health issues. **Key Points**: - **Study Length**: The study involves monitoring growth after the first month. - **Visits Needed**: Regular check-ins for growth measurements and health monitoring. - **Safety and Growth**: Aimed at ensuring safety and improved growth from switching to formula. Families may consider participating if their baby meets the criteria and they are interested in potential growth benefits from formula.