From early stress to 12-month development in very preterm infants: Preliminary findings on epigenetic mechanisms and brain growth

Very preterm (VPT) infants admitted to Neonatal Intensive Care Unit (NICU) are at risk for altered brain growth and less-than-optimal socio-emotional development. Recent research suggests that early NICU-related stress contributes to socio-emotional impairments in VPT infants at 3 months through epigenetic regulation (i.e., DNA methylation) of the serotonin transporter gene (SLC6A4). In the present longitudinal study we assessed: (a) the effects of NICU-related stress and SLC6A4 methylation variations from birth to discharge on brain development at term equivalent age (TEA); (b) the association between brain volume at TEA and socio-emotional development (i.e., Personal-Social scale of Griffith Mental Development Scales, GMDS) at 12 months corrected age (CA). Twenty-four infants had complete data at 12-month-age. SLC6A4 methylation was measured at a specific CpG previously associated with NICU-related stress and socio-emotional stress. Findings confirmed that higher NICU-related stress associated with greater increase of SLC6A4 methylation at NICU discharge. Moreover, higher SLC6A4 discharge methylation was associated with reduced anterior temporal lobe (ATL) volume at TEA, which in turn was significantly associated with less-than-optimal GMDS Personal-Social scale score at 12 months CA. The reduced ATL volume at TEA mediated the pathway linking stress-related increase in SLC6A4 methylation at NICU discharge and socio-emotional development at 12 months CA. These findings suggest that early adversity-related epigenetic changes might contribute to the long-lasting programming of socio-emotional development in VPT infants through epigenetic regulation and structural modifications of the developing brain

Pain-related increase in serotonin transporter gene methylation associates with emotional regulation in 4.5-year-old preterm-born children.

The main goal of this study was to assess the association between pain-related increase in serotonin transporter gene (SLC6A4) methylation and emotional dysregulation in 4.5-year-old preterm children compared with full-term matched counterparts. METHODS: Preterm (n = 29) and full-term (n = 26) children recruited from two Italian hospitals were followed-up from October 2011 to December 2017. SLC6A4 methylation was assessed from cord blood at birth from both groups and peripheral blood at discharge for preterm ones. At 4.5 years, emotional regulation (ie, anger, fear and sadness) was assessed through an observational standardised procedure. RESULTS: Preterm children (18 females; mean age = 4.5, range = 4.3-4.8) showed greater anger display compared with full-term controls (14 females; mean age = 4.5, range = 4.4-4.9) in response to emotional stress. Controlling for adverse life events occurrence from discharge to 4.5 years and SLC6A4 methylation at birth, CpG-specific SLC6A4 methylation in the neonatal period was predictive of greater anger display in preterm children but not in full-term ones. CONCLUSION: These findings contribute to highlight how epigenetic regulation of serotonin transporter gene in response to NICU pain exposure contributes to long-lasting programming of anger regulation in preterm children

Cranial ultrasound findings in late preterm infants and correlation with perinatal risk factors

Background: Late preterm infants are the most represented premature babies. They are exposed to a wide spectrum of brain lesions which are often clinically silent, supporting a possible role of cerebral ultrasound screening. Aim of the study is to describe the pattern of cranial ultrasound abnormalities in late preterm infants and to define the need for cranial ultrasound according to perinatal risk factors. Methods: A hospital-based cranial ultrasound screening was carried out by performing two scans (at 1 and 5 weeks). Unfavorable cranial ultrasound at 5 weeks was defined as either persistent periventricular hyperechogenicity or severe abnormalities. Results: One thousand one hundred seventy-two infants were included. Periventricular hyperechogenicity and severe abnormalities were observed in, respectively, 19.6 % and 1 % of late preterms at birth versus 1.8 % and 1.4 % at 5 weeks. Periventricular hyperechogenicity resolved in 91.3 %. At the univariate analysis gestational age (OR 0.5, 95 % CI 0.32-0.77), Apgar score <5 at 5' (OR 15.3, 1.35-173) and comorbidities (OR 4.62, 2.39-8.98) predicted unfavorable ultrasound at 5 weeks. At the multivariate analysis the accuracy in predicting unfavorable ultrasound, estimated by combined gestational age/Apgar/comorbidities ROC curve, was fair (AUC 74.6) and increased to excellent (AUC 89.4) when ultrasound at birth was included. Conclusion: Gestational age and comorbitidies are the most important risk factors for detecting brain lesions. The combination of being born at 34 weeks and developing RDS represents the strongest indication to perform a cranial ultrasound. Differently from other studies, twin pregnancy doesn't represent a risk factor

Maternal sensitivity buffers the association between SLC6A4 methylation and socio-emotional stress response in 3-month-old full term, but not very preterm infants

Background: Very preterm (VPT) infants are hospitalized in Neonatal Intensive Care Units (NICUs) and are exposed to life-saving procedures eliciting pain-related stress. Recent research documented that pain-related stress might result in birth-to-discharge increased methylation of serotonin transporter gene (SLC6A4) in VPT infants, leading to poorer stress regulation at 3 months of age in VPT infants compared to their full-term (FT) counterparts. Maternal sensitivity is thought to support infants' stress response, but its role in moderating the effects of altered SLC6A4 methylation is unknown. Main aim: To assess the role of maternal sensitivity in moderating the association between altered SLC6A4 methylation and stress response in 3-month-old VPT and FT infants. Methods: 53 infants (27 VPTs, 26 FTs) and their mothers were enrolled. SLC6A4 methylation was obtained from peripheral blood samples at NICU discharge for VPT infants and from cord blood at birth for FT infants. At 3 months (age corrected for prematurity), both groups participated to the face-to-face still-face (FFSF) paradigm to measure both infants' stress response (i.e., negative emotionality) and maternal sensitivity. Results: Maternal sensitivity did not significantly differ between VPT and FT infants' mothers. In VPT infants, higher SLC6A4 methylation at hospital discharge associates with higher negative emotionality during the FFSF. In FT infants, SLC6A4 methylation and maternal sensitivity significantly interacted to predict stress response: a positive significant association between SLC6A4 methylation and negative emotionality emerged only in FT infants of less-sensitive mothers. Discussion: Although no differences emerged in caregiving behavior in the two groups of mothers, maternal sensitivity was effective in moderating the effects of SLC6A4 methylation in FT infants, but not in VPT infants at 3 months. Speculatively, the buffering effect of maternal sensitivity observed in FT infants was disrupted by the altered early mother-infant contact due to NICU stay of the VPT group. These findings indirectly support that the effects of maternal sensitivity on infants' socio-emotional development might be time dependent, and that mother-infant interventions in the NICU need to be provided precociously within a narrow sensitive period after VPT birth

Consensus protocol for EEG and amplitude-integrated EEG assessment and monitoring in neonates

The aim of this work is to establish inclusive guidelines on electroencephalography (EEG) applicable to all neonatal intensive care units (NICUs). Guidelines on ideal EEG monitoring for neonates are available, but there are significant barriers to their implementation in many centres around the world. These include barriers due to limited resources regarding the availability of equipment and technical and interpretive round-the-clock personnel. On the other hand, despite its limitations, amplitude-integrated EEG (aEEG) (previously called Cerebral Function Monitor [CFM]) is a common alternative used in NICUs. The Italian Neonatal Seizure Collaborative Network (INNESCO), working with all national scientific societies interested in the field of neonatal clinical neurophysiology, performed a systematic literature review and promoted interdisciplinary discussions among experts (neonatologists, paediatric neurologists, neurophysiologists, technicians) between 2017 and 2020 with the aim of elaborating shared recommendations. A consensus statement on videoEEG (vEEG) and aEEG for the principal neonatal indications was established. The authors propose a flexible frame of recommendations based on the complementary use of vEEG and aEEG applicable to the various neonatal units with different levels of complexity according to local resources and specific patient features. Suggestions for promoting cooperation between neonatologists, paediatric neurologists, and neurophysiologists, organisational restructuring, and teleneurophysiology implementation are provided