Supplementary Material for: Early Brain Activity in Very Preterm Infants of Mothers with Gestational Diabetes Mellitus: A Pilot Study

<b><i>Introduction:</i></b> Neurological consequences of preterm infants born to mothers with gestational diabetes mellitus (GDM) are unclear. In this pilot study, we investigated the effect of GDM on brain activity in very preterm infants. <b><i>Methods:</i></b> Preterm infants &lt;32 gestational weeks of mothers with GDM compared to gestational age- and sex-matched controls born between 2011 and 2018 were included. Amplitude-integrated electroencephalography (aEEG) was assessed for total maturation and individual component scores according to Burdjalov and colleagues, the dominating visual background, and the presence of sleep-wake cycles per hour in the first 72 h of life and weekly at days 7, 14, 21, and 28. <b><i>Results:</i></b> We included 47 infants of mothers with GDM and 94 control infants. Both the aEEG total maturation score and its individual component scores, as well as the percentage of continuous background pattern, increased equally during the first 4 weeks after birth in both groups. GDM-exposed infants showed a slightly but significantly higher number of sleep-wake cycles per hour. <b><i>Conclusion:</i></b> We found normal maturation of brain activity in the first 4 weeks after birth in very preterm infants born to mothers with GDM, not differing from a very preterm control group. The higher number of sleep-wake cycles per hour in GDM-exposed infants could indicate transiently enhanced maturation. Further studies on brain activity and brain development in very preterm infants of mothers with GDM are needed to validate our results.