IGF1 and bronchopulmonary dysplasia: To assess the postnatal influence of IGF1 secretion, we investigated the frequency of infantile complications that may be associated with low IGF1 concentration, such as bronchopulmonary dysplasia (BPD; defined as the need for additional oxygen after the age of 28 days), retinopathy of prematurity (ROP; defined as the need for treatment by an ophthalmologist), and poor brain development (defined as abnormal brain magnetic resonance imaging findings (MRI) at the time of discharge).