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.ConclusionThere is a rationale for clinical trials to evaluate the potential benefits of IGF‐1 replacement in very preterm infants.

The neonatal period of very preterm infants is often characterized by a difficult adjustment to extrauterine life, with an inadequate nutrient supply and insufficient levels of growth factors, resulting in poor growth and a high morbidity rate. Long-term multisystem complications include cognitive, behavioral, and motor dysfunction as a result of brain damage as well as visual and hearing deficits and metabolic disorders that persist into adulthood. Insulinlike growth factor 1 (IGF-1) is a major regulator of fetal growth and development of most organs especially the central nervous system including the retina. Glucose metabolism in the developing brain is controlled by IGF-1 which also stimulates differentiation and prevents apoptosis. Serum concentrations of IGF-1 decrease to very low levels after very preterm birth and remain low for most of the perinatal development. Strong correlations have been found between low neonatal serum concentrations of IGF-1 and poor brain and retinal growth as well as poor general growth with multiorgan morbidities, such as intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, and necrotizing enterocolitis. Experimental and clinical studies indicate that early supplementation with IGF-1 can improve growth in catabolic states and reduce brain injury after hypoxic/ischemic events. A multicenter phase II study is currently underway to determine whether intravenous replacement of human recombinant IGF-1 up to normal intrauterine serum concentrations can improve growth and development and reduce prematurity-associated morbidities.

Aim This nonsystematic review examined differences in the composition of raw maternal breastmilk and pasteurised donor milk and possible health effects on preterm infants. Methods We searched PubMed up to July 2018 for studies published in English that focused on four comparisons as follows: raw maternal milk versus donor milk, human milk before and after Holder pasteurisation, milk from mothers who delivered preterm and at term and milk collected during early and late lactation. We also searched for possible effects of the milk components, as well as the effects of maternal and donor milk on preterm infants’ health. Results Raw maternal milk contained factors involved in antioxidant and anti‐inflammatory defence, gut microbiome establishment and the maturation of immune defences, food tolerability and metabolism. Many of these factors were reduced or abolished in processed donor milk. Both maternal milk and donor milk have been associated with a reduced incidence of necrotising enterocolitis. High‐dose feeding with maternal milk during the neonatal period reportedly reduced the risk of other morbidities and promoted growth and neurodevelopment. Conclusion Many of the components in raw maternal breastmilk were lacking in pasteurised donor milk, which was inferior in promoting the growth and development of very preterm infants.

Retinopathy of prematurity is a potentially blinding disease, which is associated with low neonatal IGF-I serum concentrations and poor growth. In severe cases impaired retinal vessel growth is followed by pathologic neovascularization, which may lead to retinal detachment. IGF-I may promote growth even in catabolic states. Treating preterm infants with recombinant human (rh) IGF-I to concentrations normally found during gestation has been suggested to have a preventative effect on ROP. A recent phase 2 study treating infants (gestational age between 23 weeks+ 0 days and 27 weeks + 6 days) with rhIGF-I/IGF binding protein-3 until 30 postmenstrual weeks showed no effect on ROP but a 53% reduction in severe bronchopulmonary dysplasia and 44% reduction in severe intraventricular hemorrhage. Oxygen is a major risk factor for ROP and during the phase 2 study oxygen saturation targets were increased to 90–95%, due to national guidelines, which might have affected ROP rate and severity making increased IGF-I a weaker preventative factor for ROP.

ObjectivePrematurity is a major risk factor for retinopathy of prematurity (ROP). We aimed to elucidate ROP prevalence, treatment and retreatment in infants born before 24 gestational age (GA) weeks in a Swedish cohort.Methods and analysisInfants with completed ROP screening, born at <24 GA weeks, 2007–2018 in Sweden were included. Data of GA, birth weight (BW), sex, neonatal morbidities, maximal ROP stage, aggressive posterior ROP (APROP), ROP treatments, treatment modality and treatment centre were retrieved.ResultsIn total, 399 infants, with a mean GA of 23.2 weeks (range 21.9–23.9) and a mean BW of 567 g (range 340–874), were included. ROP was detected in 365 (91.5%) infants, 173 (43.4%) were treated for ROP and 68 of 173 (39.3%) were treated more than once. As the first treatment, 142 (82.0%) received laser and 29 (16.1%) received intravitreal injection of antivascular endothelial growth factor (anti-VEGF). Retreatment was performed after first laser in 46 of 142 (32.4%) and in 20 of 29 (69.0%) after first anti-VEGF treatment. Retreatment rate was not associated with GA, BW or sex but with APROP, treatment method (anti-VEGF) and treatment centre where the laser was performed (p<0.001). Twenty eyes progressed to retinal detachment, and two infants developed unilateral endophthalmitis after anti-VEGF treatment.ConclusionInfants, born at <24 weeks’ GA, had high rates of treatment-warranting ROP and retreatments. Treatment centre highly influenced the retreatment rate after laser indicating that laser treatment could be improved in some settings.