Supplementary Material for: Influence of Sunflower Seed Oil on the Skin Barrier Function of Preterm Infants: A Randomized Controlled Trial

<p><b><i>Background:</i></b> Inadequate skin care may increase morbidity in preterm infants. Skin care practices that support skin maturation have barely been investigated. <b><i>Objectives:</i></b> To investigate the effect of sunflower seed oil (SSO) on skin barrier development in low-birth-weight premature infants. <b><i>Methods:</i></b> 22 preterm infants (<48 h after birth, 1,500-2,500 g) were randomized into group C (control) and group SSO, receiving daily SSO application during the first 10 postnatal days, followed by no intervention. Transepidermal water loss (TEWL), stratum corneum hydration (SCH), skin pH and sebum were measured <48 h after birth and on postnatal days 5, 11 and 21 on the forehead, abdomen, thigh and buttock. <b><i>Results:</i></b> Skin pH decreased, while sebum remained stable in both groups. In group C, TEWL remained stable; in group SSO, TEWL increased significantly on the abdomen, leg and buttock until day 11, followed by a decrease after SSO application had been stopped. Abdomen SCH remained stable in group C, but continuously decreased in group SSO until day 21. <b><i>Conclusion:</i></b> SSO application may retard postnatal skin barrier maturation in preterm infants.</p>