Better understanding of the appropriate IGF-1 dose in ROP prevention could be achieved from the ongoing trial using SHP607 (recombinant protein complex of IGF-1/IGFBP3, continuous intravenous infusion of SHP607 250 mcg/kg/24 hr and 400 mcg/kg/24 hours from birth to postmenstrual age 29 weeks+6 days, ClinicalTrials.gov Identifier: NCT03253263). Here, IGF1 is linked to retinopathy of prematurity.