Ruth E. Grunau

Prenatal exposure to maternal depression, neonatal methylation of human glucocorticoid receptor gene (NR3C1) and infant cortisol stress responses

Background: In animal models, variations in early maternal care are associated with differences in hypothalamic-pituitary-adrenal (HPA) stress response in the offspring, mediated via changes in the epigenetic regulation of glucocorticoid receptor (GR) gene (Nr3c1) expression. Objective: To study this in humans, relationships between prenatal exposure to maternal mood and the methylation status of a CpG-rich region in the promoter and exon 1F of the human GR gene (NR3C1) in newborns and HPA stress reactivity at age 3 months were examined. Methods: The methylation status of a CpG-rich region of the NR3C1 gene, including exon 1F, in genomic DNA from cord blood mononuclear cells was quantified by bisulfite pyrosequencing in infants of depressed mothers treated with a serotonin reuptake inhibitor antidepressant (SRI) (n=33), infants of depressed non treated mothers (n=13) and infants of non depressed/non treated mothers (n=36). To study the functional implications of the newborn methylation status of NR3C1 in newborns, HPA function was assessed at 3 months using salivary cortisol obtained before and following a non noxious stressor and at a late afternoon basal time. Results: Prenatal exposure to increased third trimester maternal depressed/anxious mood was associated with increased methylation of NR3C1 at a predicted NGFI-A binding site. Increased NR3C1 methylation at this site was also associated with increased salivary cortisol stress responses at 3 months, controlling for prenatal SRI exposure, postnatal age, and pre and postnatal maternal mood. Conclusions: Methylation status of the human NR3C1 gene in newborns is sensitive to prenatal maternal mood and may offer a potential epigenetic process that links antenatal maternal mood and altered HPA stress reactivity during infancy.

Pain expression in neonates: facial action and cry

&NA; Pain expression in neonates instigated by heel‐lance for blood sampling purposes was systematically described using measures of facial expression and cry and compared across sleep/waking states and sex. From gate‐control theory it was hypothesized that pain behavior would vary with the ongoing functional state of the infant, rather than solely reflecting tissue insult. Awake‐alert but inactive infants responded with the most facial activity, consistent with current views that infants in this state are most receptive to environmental stimulation. Infants in quiet sleep showed the least facial reaction and the longest latency to cry. Fundamental frequency of cry was not related to sleep/waking state. This suggested that findings from the cry literature on qualities of pain cry as a reflection of nervous system ‘stress’, in unwell newborns, do not generalize directly to healthy infants as a function of state. Sex differences were apparent in speed of response, with boys showing shorter time to cry and to display facial action following heel‐lance. The findings of facial action variation across sleep/waking state were interpreted as indicating that the biological and behavioral context of pain events affects behavioral expression, even at the earliest time developmentally, before the opportunity for learned response patterns occurs. Issues raised by the study include the importance of using measurement techniques which are independent of preconceived categories of affective response.

Pain in the preterm neonate: behavioural and physiological indices

&NA; The impact of invasive procedures on preterm neonates has received little systematic attention. We examined facial activity, body movements, and physiological measures in 56 preterm and full‐term newborns in response to heel lancing, along with comparison preparatory and recovery intervals. The measures were recorded in special care and full‐term nurseries during routine blood sampling. Data analyses indicated that in all measurement categories reactions of greatest magnitude were to the lancing procedure. Neonates with gestational ages as short as 25–27 weeks displayed physiological responsivity to the heel lance, but only in the heart rate measure did this vary with gestational age. Bodily activity was diminished in preterm neonates in general, relative to full‐term newborns. Facial activity increased with the gestational age of the infant. Specificity of the response to the heel lance was greatest on the facial activity measure. Identification of pain requires attention to gestational age in the preterm neonate.

Neonatal facial and cry responses to invasive and non-invasive procedures

&NA; Evaluation of pain in neonates is difficult due to their limited means of communication. The aim was to determine whether behavioural reactions of cry and facial activity provoked by an invasive procedure could be discriminated from responses to non‐invasive tactile events. Thirty‐six healthy full‐term infants (mean age 2.2 h) received 3 procedures in counterbalanced order: intramuscular injection, application of triple dye to the umbilical stub, and rubbing thigh with alcohol. Significant effects of procedure were found for total face activity and latency to face movement. A cluster of facial actions comprised of brow bulging, eyes squeezed shut, deepening of the naso‐labial furrow and open mouth was associated most frequently with the invasive procedure. Comparisons between the 2 non‐invasive procedures showed more facial activity to thigh swabbing and least to application of triple dye to the umbilical cord. Acoustic analysis of cry showed statistically significant differences across procedures only for latency to cry and cry duration for the group as a whole. However, babies who cried to two procedures showed higher pitch and greater intensity to the injection. There were no significant differences in melody, dysphonation, or jitter. Methodological difficulties for investigators in this area were examined, including criteria for the selection of cries for analysis, and the logical and statistical challenges of contrasting cries induced by different conditions when some babies do not always cry. It was concluded that facial expression, in combination with short latency to onset of cry and long duration of first cry cycle typifies reaction to acute invasive procedures.

Procedural pain and brain development in premature newborns.

Preterm infants are exposed to multiple painful procedures in the neonatal intensive care unit (NICU) during a period of rapid brain development. Our aim was to examine relationships between procedural pain in the NICU and early brain development in very preterm infants.

Neonatal procedural pain exposure predicts lower cortisol and behavioral reactivity in preterm infants in the NICU

Data from animal models indicate that neonatal stress or pain can permanently alter subsequent behavioral and/or physiological reactivity to stressors. However, cumulative effects of pain related to acute procedures in the neonatal intensive care unit (NICU) on later stress and/or pain reactivity has received limited attention. The objective of this study is to examine relationships between prior neonatal pain exposure (number of skin breaking procedures), and subsequent stress and pain reactivity in preterm infants in the NICU. Eighty‐seven preterm infants were studied at 32 (±1 weeks) postconceptional age (PCA). Infants who received analgesia or sedation in the 72 h prior to each study, or any postnatal dexamethasone, were excluded. Outcomes were infant responses to two different stressors studied on separate days in a repeated measures randomized crossover design: (1) plasma cortisol to stress of a fixed series of nursing procedures; (2) behavioral (Neonatal Facial Coding System; NFCS) and cardiac reactivity to pain of blood collection. Among infants born ≤28 weeks gestational age (GA), but not 29–32 weeks GA, higher cumulative neonatal procedural pain exposure was related to lower cortisol response to stress and to lower facial (but not autonomic) reactivity to pain, at 32 weeks PCA, independent of early illness severity and morphine exposure since birth. Repeated neonatal procedural pain exposure among neurodevelopmentally immature preterm infants was associated with down‐regulation of the hypothalamic–pituitary–adrenal axis, which was not counteracted with morphine. Differential effects of early pain on development of behavioral, physiologic and hormonal systems warrant further investigation.

Bedside application of the Neonatal Facial Coding System in pain assessment of premature neonates

&NA; Assessment of infant pain is a pressing concern, especially within the context of neonatal intensive care where infants may be exposed to prolonged and repeated pain during lengthy hospitalization. In the present study the feasibility of carrying out the complete Neonatal Facial Coding System (NFCS) in real time at bedside, specifically reliability, construct and concurrent validity, was evaluated in a tertiary level Neonatal Intensive Care Unit (NICU). Heel lance was used as a model of procedural pain, and observed with n=40 infants at 32 weeks gestational age. Infant sleep/wake state, NFCS facial activity and specific hand movements were coded during baseline, unwrap, swab, heel lance, squeezing and recovery events. Heart rate was recorded continuously and digitally sampled using a custom designed computer system. Repeated measures analysis of variance (ANOVA) showed statistically significant differences across events for facial activity (P<0.0001) and heart rate (P<0.0001). Planned comparisons showed facial activity unchanged during baseline, swab and unwrap, then increased significantly during heel lance (P<0.0001), increased further during squeezing (P<0.003), then decreased during recovery (P<0.0001). Systematic shifts in sleep/wake state were apparent. Rise in facial activity was consistent with increased heart rate, except that facial activity more closely paralleled initiation of the invasive event. Thus facial display was more specific to tissue damage compared with heart rate. Inter‐observer reliability was high. Construct validity of the NFCS at bedside was demonstrated as invasive procedures were distinguished from tactile. While bedside coding of behavior does not permit raters to be blind to events, mechanical recording of heart rate allowed for an independent source of concurrent validation for bedside application of the NFCS scale.

Neonatal pain, parenting stress and interaction, in relation to cognitive and motor development at 8 and 18 months in preterm infants

ABSTRACT Procedural pain in the neonatal intensive care unit triggers a cascade of physiological, behavioral and hormonal disruptions which may contribute to altered neurodevelopment in infants born very preterm, who undergo prolonged hospitalization at a time of physiological immaturity and rapid brain development. The aim of this study was to examine relationships between cumulative procedural pain (number of skin‐breaking procedures from birth to term, adjusted for early illness severity and overall intravenous morphine exposure), and later cognitive, motor abilities and behavior in very preterm infants at 8 and 18 months corrected chronological age (CCA), and further, to evaluate the extent to which parenting factors modulate these relationships over time. Participants were N = 211 infants (n = 137 born preterm ⩽32 weeks gestational age [GA] and n = 74 full‐term controls) followed prospectively since birth. Infants with significant neonatal brain injury (periventricular leucomalacia, grade 3 or 4 intraventricular hemorrhage) and/or major sensori‐neural impairments, were excluded. Poorer cognition and motor function were associated with higher number of skin‐breaking procedures, independent of early illness severity, overall intravenous morphine, and exposure to postnatal steroids. The number of skin‐breaking procedures as a marker of neonatal pain was closely related to days on mechanical ventilation. In general, greater overall exposure to intravenous morphine was associated with poorer motor development at 8 months, but not at 18 months CCA, however, specific protocols for morphine administration were not evaluated. Lower parenting stress modulated effects of neonatal pain, only on cognitive outcome at 18 months.

Early pain experience, child and family factors, as precursors of somatization: a prospective study of extremely premature and fullterm children

&NA; In a prospective study of 36 children who were extremely low birthweight (ELBW: < 1000 g) preterm infants and 36 matched full‐term controls, differences were found in somatization at age Symbol years. Only children who had been extremely premature, and thereby experienced prolonged hospitalization and repeated medical intervention in infancy, had clinically high somatization scores on the Personality Inventory for Children. The combination of family relations at age Symbol years, neonatal intensive care experience, poor maternal sensitivity to child cues in mother‐child interaction observed at age 3 years, and child avoidance of touch or holding at age 3. predicted somatization scores, prior to school entry. Due to the known higher incidence of actual medical problems among children with a history of extreme prematurity, the high somatization ELBW children were compared with the normal somatization ELBW children. There were no differences in prevalence of actual medical problems between the 2 ELBW groups, and the importance of maternal factors in relation to somatization was confirmed. Child temperament at age 3, but not personality at Symbol, was related to somatization. The etiology of recurrent physical complaints of no known medical cause appears to be a multi‐dimensional problem. Non‐optimal parenting may contribute to the development of inappropriate strategies for coping with common pains of childhood, or of chronic pain patterns, in some children who have experienced prolonged or repeated pain as neonates. Symbol. No caption available Symbol. No caption available Symbol. No caption available

Extremely premature (< or = 800 g) schoolchildren: multiple areas of hidden disability.

AIM To examine the functional abilities of extremely low birthweight (ELBW, ⩽ 800 g) children at school age compared with full term children. METHODS ELBW children (n=115) in a geographically defined regional cohort born between 1974 and mid-1985 (comprising 96% of 120 survivors of 400 ELBW infants admitted to the Provincial Tertiary neonatal intensive care unit), were compared with (n = 50) children of comparable age and sociodemographic status. Each child was categorised by the pattern and degree of disability, using a system derived from theDiagnostic and Statistical Manual of the American Psychiatric Association (DSM IV). Psycho-educational, behavioural, and motor results for ELBW children free of severe/multiple neurosensory disabilities (n=90; 91% return rate) were compared with the term children. RESULTS Severe/multiple neurosensory disabilities were present in 16 ELBW children (14%), and 15 (13%) had borderline intelligence. ELBW children of global IQ ⩾ 85 scored significantly lower in standardised tests of fine and gross motor control, visuo–motor pencil output, visual memory, and academic achievement (reading, arithmetic, written language). ELBW survivors were three times more likely to have learning disorders (47%vs 18%) and 22 (41%) of the 54 ELBW children with learning disorders had multiple areas of learning difficulty. Of the ELBW group, 30 (26%) were not disabled compared with 41 (82%) of the term group. Only five (12%) of the ELBW boys were not disabled, compared with 25 (35%) of the ELBW girls. Finally, ELBW children had significantly worse scores on ratings of behaviour during testing by the psychologist and behaviour by parental report. CONCLUSION The most likely outcome for ELBW survivors at school age is a learning disorder, often multiple, or borderline intellectual functioning, combined with behavioural and motor risk factors rather than severe/multiple disability. Mean scores on psycho-educational testing showed poorer performance of the ELBW children, but grossly understated the complex nature of the individual degree of educational difficulty faced by these children.