['Poor postnatal growth after preterm birth does not match the normal rapid growth in utero and is associated with preterm morbidities. Insulin-like growth factor 1 (IGF-1) axis is the major hormonal mediator of growth in utero, and levels of IGF-1 are often very low after preterm birth. We reviewed the role of IGF-1 in foetal development and the corresponding preterm perinatal period to highlight the potential clinical importance of IGF-1 deficiency in preterm morbidities.'] Does insulin-like growth factor 1 have multisystem effects on foetal and preterm infant development?