Differences in salivary cortisol levels in cocaine-exposed and noncocaine-exposed NICU infants

Through a teratological lens: A narrative review of exposure to stress and drugs of abuse during pregnancy on neurodevelopment

Teratological research shows that both prenatal stress and prenatal substance exposure have a significant impact on neurodevelopmental outcomes in children. Using human research, the purpose of this narrative review is to explore the degree to which these exposures may represent complex prenatal and postnatal risks for the development of cognition and behavior in children. An understanding of the HPA axis and its function during pregnancy as well as the types and operationalization of prenatal stress provide a context for understanding the direct and indirect mechanisms by which prenatal stress affects brain and behavior development. In turn, prenatal substance exposure studies are evaluated for their importance in understanding variables that indicate a potential interaction with prenatal stress including reactivity to novelty, arousal, and stress reactivity during early childhood. The similarities and differences between prenatal stress exposure and prenatal substance exposure on neurodevelopmental outcomes including arousal and emotion regulation, cognition, behavior, stress reactivity, and risk for psychopathology are summarized. Further considerations for teratological studies of prenatal stress and/or substance exposure include identifying and addressing methodological challenges, embracing the complexity of pre-and postnatal environments in the research, and the importance of incorporating parenting and resilience into future studies.

Prenatal substance exposure, early-life adversity, and parenting: Associations with adolescent stress response

We tested a conceptual model examining associations between prenatal substance exposure and adolescent cortisol reactivity profiles in response to an acute social evaluative stressor. We included cortisol reactivity in infancy, and direct and interactive effects of early-life adversity and parenting behaviors (sensitivity, harshness) from infancy to early school age on adolescent cortisol reactivity profiles in model testing. Participants were 216 families (51% female children; 116 cocaine-exposed) recruited at birth, oversampled for prenatal substance exposure, and assessed from infancy to early adolescence (EA). Majority of participants self-identified as Black (72% mothers, 57.2% adolescents), and caregivers were primarily from low-income families (76%), were single (86%), and had high school or below education (70%) at recruitment. Latent profile analyses identified three cortisol reactivity patterns including elevated (20.4%), moderate (63.1%), and blunted (16.5%) reactivity groups. Prenatal tobacco exposure was associated with higher likelihood of membership in the elevated reactivity compared to the moderate reactivity group. Higher caregiver sensitivity in early life was associated with lower likelihood of membership in the elevated reactivity group. Prenatal cocaine exposure was associated with higher maternal harshness. Interaction effects among early-life adversity and parenting indicated that caregiver sensitivity buffered, and harshness exacerbated, the likelihood that high early adversity would be associated with the elevated and blunted reactivity groups. Results highlight the potential importance of prenatal alcohol and tobacco exposure for cortisol reactivity and the role of parenting as exacerbating or buffering the impact of early-life adversity on adolescent stress response.

Assessment of salivary cortisol concentrations for procedural pain monitoring in newborns

OBJECTIVES

The study aimed to evaluate the usefulness of salivary cortisol (SC) for the assessment of procedural pain intensity in preterm and term newborns.

METHODS

Three groups of neonates (term, 37⁰-41⁶ weeks; moderate to late preterm, 32⁰-36⁶; and very preterm, <32⁰) hospitalized in neonatal intensive care unit were assessed for the study. Response to nappy change, lung ultrasound (LUS), and blood sampling was analyzed. The intensity of pain was evaluated using continuous heart rate and blood oxygen saturation (SpO₂) monitoring, Neonatal Infant Pain Scale (NIPS), and SC concentrations. Saliva samples were collected before and 20 min after the procedure's end.

RESULTS

Seventy-one infants were examined: 30 term, 21 moderate to late preterm, and 20 very preterm. SC has increased significantly in response to nappy change only in very preterm newborns (2.13 ng/mL [1.55-3.68] vs. 2.84 ng/mL [1.93-9.06], p = 0.01). LUS did not affect concentrations of SC in any group. Significant increase in SC was observed after blood sampling in term and very preterm infants (2.2 ng/mL [1.45-2.92] vs. 4.29 ng/mL [3.88-5.73], p = 0.002, and 1.88 ng/mL [1.47-4.13] vs. 5.3 ng/mL [3.42-8.02], p = 0.002, respectively). A significant correlation between values of SC increase and NIPS scores was found (Spearman's rank correlation coefficient [r_s] = 0.31, p = 0.001).

CONCLUSIONS

We observed the increase in SC concentrations in response to painful stimulus. The presence of a correlation between NIPS scores and SC increase suggests that SC can be used as an objective parameter to assess pain in neonates.

Delirium in the NICU: Risk or Reality?

Delirium is a frequent complication of critical illness in adult and pediatric populations and is associated with significant morbidity and mortality. Little is known about the incidence, risk, symptoms, or treatment of delirium in the NICU. Only 4 cases of NICU delirium have been reported, but many pediatric studies include infants. The Cornell Assessment of Pediatric Delirium tool has been validated in neonatal and infant populations for identification of delirium. Initial treatment should focus on identification and reversal of the cause, with pharmacologic management reserved for patients with symptoms that do not resolve or that significantly impact medical care. Routine use of intravenous haloperidol should be avoided because of the high incidence of serious adverse effects, but it may be considered in patients with significant symptoms who are unable to take oral medications. Atypical antipsychotics (olanzapine, quetiapine, and risperidone) appear to be efficacious with a low incidence of adverse effects. Risperidone has weight-based dosing and a liquid dosage form available, making it a good option for use in the NICU. Additional data from large cohorts of NICU patients routinely screened for delirium, and treated as indicated, are needed.

Pharmacotherapy of neonatal opioid withdrawal syndrome: a review of pharmacokinetics and pharmacodynamics

INTRODUCTION

Neonatal opioid withdrawal syndrome (NOWS) often arises in infants born to mothers who used opioids during pregnancy. Morphine, methadone, and buprenorphine are the most common first-line treatments, whereas clonidine and phenobarbital are generally reserved for adjunctive therapy. These drugs exhibit substantial pharmacokinetic (PK) and pharmacodynamic (PD) variability. Current pharmacological treatments for NOWS are based on institutional protocols and largely rely on empirical treatment of patient symptoms.

AREAS COVERED

This article reviews the PK/PD of NOWS pharmacotherapies with a focus on the implication of physiological development and maturation. Body size-standardized clearance is consistently low in neonates, except for methadone. This can be ascribed to underdeveloped metabolic and elimination pathways. The effects of pharmacogenetics have been clarified especially for morphine. The PK/PD relationship of medications used in the treatment of NOWS is generally understudied.

EXPERT OPINION

Providing an appropriate opioid dose in neonates is challenging. Advancements in quantitative pharmacology and PK/PD modeling approaches facilitate identification of key factors driving PK/PD variability and characterization of exposure-response relationships. PK/PD model-informed simulations have been widely employed to define age-appropriate pediatric dosing regimens. The model-informed approach holds promise to aid more rational use of medications in the treatment of NOWS.

Nutritional and immunological factors in breast milk: A role in the intergenerational transmission from maternal psychopathology to child development

Perinatal psychopathologies affect more than 25% of women during and after their gestational period. These psychiatric disorders can potentially determine important biological variations in their organisms, affecting many different physiological and metabolic pathways. Of relevance, any of these changes occurring in the mother can alter the normal composition of breast milk, particularly the concentration of nutritional and inflammatory components, which play a role in child brain functioning and development. Indeed, there is evidence showing that changes in milk composition can contribute to cognitive impairments and alterations in mental abilities in children. This review aims to shed light on the unique intergenerational role played by breast milk composition, from maternal psychopathologies to child development.

Pain, Parental Involvement, and Oxytocin in the Neonatal Intensive Care Unit

Preterm infants (PTI) typically experience many painful and stressful procedures or events during their first weeks of life in a neonatal intensive care unit, and these can profoundly impact subsequent brain development and function. Several protective interventions during this sensitive period stimulate the oxytocin system, reduce pain and stress, and improve brain development. This review provides an overview of the environmental risk factors experienced by PTI during hospitalization, with a focus on the effects of pain, and early maternal separation. We also describe the long-term adverse effects of the simultaneous experiences of pain and maternal separation, and the potential beneficial effects of maternal vocalizations, parental contact, and several related processes, which appear to be mediated by the oxytocin system.

Neuroendocrine and immune pathways from pre- and perinatal stress to substance abuse

Early life adversity is a documented risk factor for substance abuse and addiction. The pre- and perinatal period (i.e., from implantation, through pregnancy, to 6 months of age) is a critical period marked by high biological plasticity and vulnerability, making perinatal stress a particularly robust form of adversity. The neuroendocrine and immune systems are key mechanisms implicated in the transmission of addiction risk. We review animal and human studies that provide preliminary evidence for links between perinatal stress, neuroendocrine and immune dysregulation, and risk for substance abuse and addiction. A translational neuroscience perspective is employed to elucidate pre- and perinatally-induced biological mechanisms linked to addiction and discuss implications for prevention and intervention efforts. Significant evidence supports associations between pre- and perinatal stress and dysregulation of the hypothalamic-pituitary-adrenal axis and immune systems as well as links between neuroendocrine/immune functioning and addiction risk. More work is needed to explicitly examine the interplay between pre- and perinatal stress and neuroendocrine/immune disruptions that together heighten substance abuse risk. Future work is needed to fully understand how pre- and perinatal stress induces biological alterations to predispose individuals to higher risk for addiction. Such knowledge will strengthen theoretically-driven and empirically-supported prevention efforts for substance abuse and addiction.

Behavioral and cortisol responses to stress in newborn infants: Effects of mode of delivery

Suboptimal birth characteristics have been associated with altered reactivity to stress in infants. However, previous studies have not controlled for mode of delivery, which may influence the neonatal onset of stress responses. The present study assessed stress-related behavior and salivary cortisol before and after an inoculation at two hours after birth, and compared infants born through VD (N=70) and elective CS (N=72). The results indicated that overall stress behavior and body movements were increased immediately after inoculation in infants born through CS compared to VD. Infants born through CS did not show significant cortisol increases following inoculation and their overall cortisol reactivity (i.e., AUC_G) was lower compared to infants born through VD. However, unexpectedly, cortisol levels in infants born through VD were highest before inoculation and subsequently decreased. Cortisol was significantly related to behavior in both groups, but in opposite directions. These results support the view that mode of delivery influences neonatal stress reactivity, although future studies should try to disentangle the effects of mode of delivery and related variables.

HPA Axis Interactions with Behavioral Systems

Perhaps the most salient behaviors that individuals engage in involve the avoidance of aversive experiences and the pursuit of pleasurable experiences. Engagement in these behaviors is regulated to a significant extent by an individual's hormonal milieu. For example, glucocorticoid hormones are produced by the hypothalamic-pituitary-adrenocortical (HPA) axis, and influence most aspects of behavior. In turn, many behaviors can influence HPA axis activity. These bidirectional interactions not only coordinate an individual's physiological and behavioral states to each other, but can also tune them to environmental conditions thereby optimizing survival. The present review details the influence of the HPA axis on many types of behavior, including appetitively-motivated behaviors (e.g., food intake and drug use), aversively-motivated behaviors (e.g., anxiety-related and depressive-like) and cognitive behaviors (e.g., learning and memory). Conversely, the manuscript also describes how engaging in various behaviors influences HPA axis activity. Our current understanding of the neuronal and/or hormonal mechanisms that underlie these interactions is also summarized. © 2016 American Physiological Society. Compr Physiol 6:1897-1934, 2016.

Neonatal pain and reduced maternal care: Early-life stressors interacting to impact brain and behavioral development

Advances in neonatal intensive care units (NICUs) have drastically increased the survival chances of preterm infants. However, preterm infants are still exposed to a wide range of stressors during their stay in the NICU, which include painful procedures and reduced maternal contact. The activation of the hypothalamic-pituitary-adrenal (HPA) axis, in response to these stressors during this critical period of brain development, has been associated with many acute and long-term adverse biobehavioral outcomes. Recent research has shown that Kangaroo care, a non-pharmacological analgesic based on increased skin-to-skin contact between the neonate and the mother, negates the adverse outcomes associated with neonatal pain and reduced maternal care, however the biological mechanism remains widely unknown. This review summarizes findings from both human and rodent literature investigating neonatal pain and reduced maternal care independently, primarily focusing on the role of the HPA axis and biobehavioral outcomes. The physiological and positive outcomes of Kangaroo care will also be discussed in terms of how dampening of the HPA axis response to neonatal pain and increased maternal care may account for positive outcomes associated with Kangaroo care.

Salivary Cortisol Reactivity in Preterm Infants in Neonatal Intensive Care: An Integrative Review

Recently, more and more researchers have been using salivary cortisol reactivity to evaluate stress in preterm infants in the neonatal intensive care unit (NICU). The aim of this integrative literature review was to summarize the evidence of interventions leading to a change in salivary cortisol from the baseline in preterm infants in the NICU. The electronic databases of PubMed, CINAHL, Web of Science, and Scopus were searched for relevant studies. The inclusion criteria were studies with preterm infants exposed to an intervention evaluated by salivary cortisol reactivity before discharge from the NICU, which were published in English. In total, 16 studies were included. Eye-screening examination and heel lance provoked an increase in the salivary cortisol level. Music, prone position, and co-bedding among twins decreased the salivary cortisol level. Several studies reported a low rate of successful saliva sampling or did not use control groups. Future studies need to focus on non-painful interventions in order to learn more about salivary cortisol regulation in preterm infants. Moreover, these studies should use study designs comprising homogenous gestational and postnatal age groups, control groups, and reliable analysis methods that are able to detect cortisol in small amounts of saliva.

The Neonatal Salivary Transcriptome

The ability to noninvasively assess the physical and developmental status of a neonate is a goal of modern medicine. In recent years, technological advances have permitted the high-throughput analysis of saliva for thousands of genes, proteins, and metabolites from a single sample source. Saliva is an ideal biofluid to assess health, disease, and development in the newborn. It may be harnessed repeatedly, even in the most vulnerable patients, without risk of harm. Translating novel information about an infant's global development and risk of disease to the neonatal bedside through the salivary transcriptome has the potential to significantly improve clinical care and outcomes in this at-risk population.

Influence of prone positioning on premature newborn infant stress assessed by means of salivary cortisol measurement: pilot study

Objective

This study sought to assess the influence of prone positioning on the stress of newborn premature infants through the measurement of the salivary cortisol concentration and the evaluation of physiological and behavioral responses before and after changes in body positioning.

Methods

Saliva samples were collected from newborn infants at two different times: the first (corresponding to the baseline) after a period of 40 minutes during which the infants were not subjected to any manipulation and were placed in the lateral or supine position, and the second 30 minutes after placement in the prone position. Variables including heart rate, respiratory rate, peripheral oxygen saturation, and the Brazelton sleep score were recorded before, during, and at the end of the period in the prone position.

Results

The sample comprised 16 newborn premature infants (56.3% male) with a gestational age between 26 and 36 weeks, postnatal age between 1 and 33 days, birth weight of 935 to 3,050g, and weight at the time of intervention of 870 to 2,890g. During the intervention, six participants breathed room air, while the remainder received oxygen therapy. The median salivary cortisol concentration was lower in the prone position compared to baseline (0.13 versus 0.20; p=0.003), as was the median Brazelton sleep score (p=0.02). The average respiratory rate was lower after the intervention (54.88±7.15 versus 60±7.59; p=0.0004). The remainder of the investigated variables did not exhibit significant variation.

Conclusion

Prone positioning significantly reduced the salivary cortisol level, respiratory rate, and Brazelton sleep score, suggesting a correlation between prone positioning and reduction of stress in preterm infants.

Foetal programming and cortisol secretion in early childhood: A meta-analysis of different programming variables

It is widely recognized that different events may take place in the intrauterine environment that may influence later developmental outcome. Scholars have long postulated that maternal prenatal stress, alcohol or drug use, and cigarette smoking may impact foetal formation of the hypothalamus-pituitary-adrenal (HPA) axis, which may later influence different aspects of early childhood socioemotional and cognitive development. However, results linking each of these factors with child cortisol secretion have been mixed. The current meta-analysis examined the relation between each of these programming variables and child cortisol secretion in studies conducted up to December 31st, 2012. Studies were included if they were conducted prior to child age 60 months, and if they reported an index of effect size linking either maternal prenatal stress, alcohol or drug use, or cigarette smoking with an index of child cortisol secretion. In total, 19 studies (N=2260) revealed an average effect size of d=.36 (p<.001). Moderator analyses revealed that greater effect sizes could be traced to maternal alcohol use, to the use of retrospective research methodology, where mothers are questioned after childbirth regarding programming variables, and to the use of baseline measures of cortisol secretion, as opposed to recovery measures. Discussion focuses on processes that link the environment to foetal development and how both are linked to later adaptation.

Effects of prenatal substance exposure on infant temperament vary by context

This was a prospective longitudinal multisite study of the effects of prenatal cocaine and/or opiate exposure on temperament in 4-month-olds of the Maternal Lifestyle Study (N = 958: 366 cocaine exposed, 37 opiate exposed, 33 exposed to both drugs, 522 matched comparison). The study evaluated positivity and negativity during The Behavior Assessment of Infant Temperament (Garcia Coll et al., 1988). Parents rated temperament (Infant Behavior Questionnaire; Rothbart, 1981). Cocaine-exposed infants showed less positivity overall, mainly during activity and threshold items, more negativity during sociability items, and less negativity during irritability and threshold items. Latent profile analysis indicated individual temperament patterns were best described by three groups: low/moderate overall reactivity, high social negative reactivity, and high nonsocial negative reactivity. Infants with heavy cocaine exposure were more likely in high social negative reactivity profile, were less negative during threshold items, and required longer soothing intervention. Cocaine- and opiate-exposed infants scored lower on Infant Behavior Questionnaire smiling and laughter and duration of orienting scales. Opiate-exposed infants were rated as less respondent to soothing. By including a multitask measure of temperament we were able to show context-specific behavioral dysregulation in prenatally cocaine-exposed infants. The findings indicate flatter temperament may be specific to nonsocial contexts, whereas social interactions may be more distressing for cocaine-exposed infants.

Cortisol reactivity to social stress as a mediator of early adversity on risk and adaptive outcomes

Children chronically exposed to stress early in life are at increased risk for maladaptive outcomes, though the physiological mechanisms driving these effects are unknown. Cortisol reactivity was tested as a mediator of the relation between prenatal substance exposure and/or early adversity on adaptive and maladaptive outcomes. Data were drawn from a prospective longitudinal study of prenatal substance exposure (N = 860). Cortisol reactivity was assessed at age 11. Among African Americans, prenatal substance exposure exerted an indirect effect through early adversity and cortisol reactivity to predict externalizing behavior, delinquency, and a positive student-teacher relationship at age 11. Decreased cortisol reactivity was related to maladaptive outcomes, and increased cortisol reactivity predicted better executive functioning and a more positive student-teacher relationship.

Empathic responsivity at 3 years of age in a sample of cocaine-exposed children

This study examined the association between prenatal exposure to cocaine and behavioral and physiological responsivity. Participants were 216 mother-infant dyads (116 cocaine exposed-CE, 100 nonexposed-NCE) recruited at birth. Measures of heart rate (HR) and respiratory sinus arrhythmia (RSA) were obtained during baseline and during a task designed to elicit empathy (exposure to infant crying). When the effects of prenatal cocaine use were examined in the context of polydrug use, results of model testing indicated that lower gestational age, prenatal exposure to cocaine and postnatal exposure to alcohol were each associated with a reduced suppression of RSA during the empathy task. These findings provide additional support for an association between prenatal cocaine exposure and dysregulation during early childhood during affect-eliciting environmental challenges.

Developmental and behavioral consequences of prenatal cocaine exposure: a review

Substance use among pregnant women continues to be a major public health concern, posing potential risk to their drug-exposed children as well as burdens on society. This review is intended to discuss the most recent literature regarding the association between in utero cocaine exposure and developmental and behavioral outcomes from birth through adolescence across various domains of functioning (growth, neurobiology, intelligence, academic achievement, language, executive functioning, behavioral regulation and psychopathology). In addition, methodological limitations, associated biological, sociodemographic and environmental risk factors and future directions in this area of research are discussed. Given the large number of exposed children in the child welfare system and the increased need for medical, mental health and special education services within this population, more definitively documenting associations between prenatal cocaine exposure and later child outcomes is essential in order to be able to prospectively address the many significant public health, economic and public policy implications.

The Stockholm Neonatal Family-Centered Care Study: effects on salivary cortisol in infants and their mothers

BACKGROUND

Parental involvement in the care of preterm infants in neonatal intensive care units (NICUs) is common, but little is known about the effect on stress responses in mothers and infants.

AIMS

The aim of this study is to evaluate the effect of family-centered care on salivary cortisol reactivity in mothers and preterm infants and the correlation between the mothers' and the preterm infants' salivary cortisol levels.

METHODS

This study is part of a randomized controlled trial conducted at two level-II NICUs, including Family Care (FC), where parents were able to stay 24h/day from admission to discharge, and Standard Care (SC). To investigate the cortisol response, saliva was collected from 289 preterm infants and their mothers before and after a diaper change at the time of discharge.

RESULTS

No significant differences were found between the two groups in salivary cortisol reactivity, either in mothers or in infants. The results revealed a correlation between preterm infants' and their mothers' baseline and response cortisol in the FC group: r=0.31 (p=0.001) and r=0.24 (p=0.01), respectively. Such correlation was not observed in the SC group: r=0.14 (p=0.14) and r=0.18 (p=0.07), respectively.

CONCLUSIONS

Family-centered care had no effect on salivary cortisol reactivity during diaper change. However, sharing the same environment may increase the concordance between preterm infants' and their mothers' salivary cortisol levels.

The combined effects of prenatal drug exposure and early adversity on neurobehavioral disinhibition in childhood and adolescence

The negative effects of prenatal substance exposure on neurobiological and psychological development and of early adversity are clear, but little is known about their combined effects. In this study, multilevel analyses of the effects of prenatal substance exposure and early adversity on the emergence of neurobehavioral disinhibition in adolescence were conducted. Neurobehavioral disinhibition has previously been observed to occur frequently in multiproblem youth from high-risk backgrounds. In the present study, neurobehavioral disinhibition was assessed via behavioral dysregulation and poor executive function composite measures. Data were drawn from a prospective longitudinal investigation of prenatal substance exposure that included 1,073 participants followed from birth through adolescence. The results from latent growth modeling analyses showed mean stability but significant individual differences in behavioral dysregulation and mean decline with individual differences in executive function difficulties. Prior behavioral dysregulation predicted increased executive function difficulties. Prenatal drug use predicted the emergence and growth in neurobehavioral disinhibition across adolescence (directly for behavioral dysregulation and indirectly for executive function difficulties via early adversity and behavioral dysregulation). Prenatal drug use and early adversity exhibited unique effects on growth in behavioral dysregulation; early adversity uniquely predicted executive function difficulties. These results are discussed in terms of implications for theory development, social policy, and prevention science.

Altered stress responses in children exposed to early adversity: a systematic review of salivary cortisol studies

Pathological stress responses are implicated in numerous disorders. Hypothalamic-pituitary-adrenal axis function is influenced by gene-environment interaction, with early-life environmental adversity having long-lasting effects. We examine the evidence that, in humans, these effects are apparent from infancy. We systematically reviewed published findings on cortisol response to a stressor, in 0-5-year-olds already exposed to adversity. Adversity was defined as a negative environmental influence present post-conception. We searched Ovid MEDLINE (1950-May 2010), EMBASE (1980-May 2010) and PsychINFO (1806-May 2010). We included peer-reviewed, English language studies that analysed salivary cortisol before and after a standardised stressor. We identified 30 studies, of which 27 reported a significant effect of adversity on the cortisol response to stress. Six of these demonstrated an effect of prenatal substance exposure. Thirteen studies found that psychosocial adversity increased cortisol reactivity. Three studies reported that cortisol reactivity could be normalised by intervention programmes. The studies were heterogeneous, both in nature of adversity studied and in stressor used, precluding meta-analysis and assessment of publication bias. Our review presents evidence that adversity disrupts the stress response from an early age. Longitudinal studies are required to determine whether effects persist, alter with time, or are reversible with intervention.

Prenatal Cocaine Disrupts Serotonin Signaling-Dependent Behaviors: Implications for Sex Differences, Early Stress and Prenatal SSRI Exposure

Prenatal cocaine (PC) exposure negatively impacts the developing nervous system, including numerous changes in serotonergic signaling. Cocaine, a competitive antagonist of the serotonin transporter, similar to selective serotonin reuptake inhibitors (SSRIs), also blocks dopamine and norepinephrine transporters, leaving the direct mechanism through which cocaine disrupts the developing serotonin system unclear. In order to understand the role of the serotonin transporter in cocaine's effect on the serotonergic system, we compare reports concerning PC and prenatal antidepressant exposure and conclude that PC exposure affects many facets of serotonergic signaling (serotonin levels, receptors, transporters) and that these effects differ significantly from what is observed following prenatal SSRI exposure. Alterations in serotonergic signaling are dependent on timing of exposure, test regimens, and sex. Following PC exposure, behavioral disturbances are observed in attention, emotional behavior and stress response, aggression, social behavior, communication, and like changes in serotonergic signaling, these effects depend on sex, age and developmental exposure. Vulnerability to the effects of PC exposure can be mediated by several factors, including allelic variance in serotonergic signaling genes, being male (although fewer studies have investigated female offspring), and experiencing the adverse early environments that are commonly coincident with maternal drug use. Early environmental stress results in disruptions in serotonergic signaling analogous to those observed with PC exposure and these may interact to produce greater behavioral effects observed in children of drug-abusing mothers. We conclude that based on past evidence, future studies should put a greater emphasis on including females and monitoring environmental factors when studying the impact of PC exposure.

Long-term impact of maternal substance use during pregnancy and extrauterine environmental adversity: stress hormone levels of preadolescent children

Prenatal cocaine exposure (PCE) is associated with blunted stress responsivity within the extrauterine environment. This study investigated the association between PCE and diurnal salivary cortisol levels in preadolescent children characterized by high biological and/or social risk (n = 725). Saliva samples were collected at their home. Analyses revealed no group differences in basal evening or morning cortisol levels; however, children with higher degrees of PCE exhibited blunted overnight increases in cortisol, controlling for additional risk factors. Race and caregiver depression were also associated with diurnal cortisol patterns. Although repeated PCE may contribute to alterations in the normal or expected stress response later in life, sociodemographic and environmental factors are likewise important in understanding hormone physiology, especially as more time elapses from the PCE. Anticipating the potential long-term medical, developmental, or behavioral effects of an altered ability to mount a normal protective cortisol stress response is essential in optimizing the outcomes of children with PCE.

Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA Axis Reactivity During a Psychosocial Stressor

Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without prenatal substance exposure (N = 53; ages 9-12 years) were examined using the Trier Social Stress Test for Children. Area under the curve with respect to increase (AUC(I)) analyses revealed that prenatal substance exposure or physical abuse significantly increased the likelihood of a negative AUC(I) (i.e., little or no HPA reactivity). Among children with prenatal substance exposure and physical abuse, 85% exhibited a negative AUC(I). The results underscore the importance of addressing this combined risk.

Effects of perinatal cocaine exposure on open field behavior and the response to corticotropin releasing hormone (CRH) in rat offspring

Previous reports indicate that prenatal cocaine exposure alters specific behaviors and hypothalamic-pituitary-adrenal axis (HPA) function in the offspring. In most previous studies, cocaine was given via subcutaneous injections. However intravenous administration more closely mimics human cocaine abuse during pregnancy. Therefore, we investigated the effects of prenatal cocaine exposure via intravenous injection to the mothers on open field behavior and HPA axis function of the offspring. We hypothesized that prenatal cocaine exposure decreases immobility in a novel environment, and enhances the HPA response to stress. Dams received cocaine (COC) or vehicle (control, CON) intravenously from gestation day 8 to postnatal day (PD) 5. Behaviors were recorded in the open field on PD 28 (weanlings). As expected, perinatally cocaine-exposed offspring spent less time immobile and had a longer latency to entering the center zone. No other behavioral activities were different between the groups. On PD 43-50, adolescent male and female offspring received either corticotropin releasing hormone (CRH) or saline intravenously. Plasma adrenocorticotropic hormone (ACTH) and corticosterone (CORT) levels were determined before, and up to 60 min after injection. COC-exposed offspring of both sexes had higher basal CORT levels. Prenatal cocaine enhanced the CORT response to CRH/saline injections up to 60 min in males but not in females. These novel results show that perinatal administration of cocaine in a manner that most closely mimics human cocaine use has long-term effects on the offspring's behavioral response to stress and on HPA axis functions.

Prenatal cocaine exposure, gender, and adolescent stress response: a prospective longitudinal study

Prenatal cocaine exposure is associated with alterations in arousal regulation in response to stress in young children. However, relations between cocaine exposure and stress response in adolescence have not been examined. We examined salivary cortisol, self-reported emotion, heart rate, and blood pressure (BP) responses to the Trier Social Stress Test (TSST) in 49 prenatally cocaine and other drug exposed (PCE) and 33 non-cocaine-exposed (NCE) adolescents. PCE adolescents had higher cortisol levels before and after stress exposure than NCE adolescents. PCE girls showed an elevated anxiety response to stress (compared to NCE girls) and PCE boys showed a dampened diastolic BP response (compared to NCE boys). Girls showed higher anger response and lower pre-stress systolic BP than boys. Group differences were found controlling for potential confounding variables and were not moderated by caregiver-child relationship quality (although relationship quality predicted HPA axis and anxiety response). The findings suggest that prenatal drug exposure is associated with altered stress response in adolescence and that gender moderates this association.

Prenatal cocaine exposure related to cortisol stress reactivity in 11-year-old children

OBJECTIVE

Determine the association between prenatal cocaine exposure and postnatal environmental adversity on salivary cortisol stress reactivity in school-aged children.

STUDY DESIGN

Subjects included 743 11-year-old children (n = 320 cocaine-exposed; 423 comparison) followed since birth in a longitudinal prospective multisite study. Saliva samples were collected to measure cortisol at baseline and after a standardized procedure to induce psychological stress. Children were divided into those who showed an increase in cortisol from baseline to post stress and those who showed a decrease or blunted cortisol response. Covariates measured included site, birthweight, maternal pre and postnatal use of alcohol, tobacco or marijuana, social class, changes in caretakers, maternal depression and psychological symptoms, domestic and community violence, child abuse, and quality of the home.

RESULTS

With adjustment for confounding variables, cortisol reactivity to stress was more likely to be blunted in children with prenatal cocaine exposure. Children exposed to cocaine and who experienced domestic violence showed the strongest effects.

CONCLUSIONS

The combination of prenatal cocaine exposure and an adverse postnatal environment could downregulate the hypothalamic-pituitary-adrenal axis resulting in the blunted cortisol response to stress possibly increasing risk for later psychopathology and adult disease.

Prenatal alcohol exposure alters biobehavioral reactivity to pain in newborns

OBJECTIVES

To examine biobehavioral responses to an acute pain event in a Cape Town, South Africa, cohort consisting of 28 Cape Colored (mixed ancestry) newborns (n = 14) heavily exposed to alcohol during pregnancy (exposed), and born to abstainers (n = 14) or light (< or = 0.5 oz absolute alcohol/d) drinkers (controls).

METHODS

Mothers were recruited during the third trimester of pregnancy. Newborn data were collected on postpartum day 3 in the maternity obstetrical unit where the infant had been delivered. Heavy prenatal alcohol exposure was defined as maternal consumption of at least 14 drinks/wk or at least 1 incident of binge drinking/mo. Acute stress-related biobehavioral markers [salivary cortisol, heart rate (HR), respiratory sinus arrhythmia (RSA), spectral measures of heart rate variability (HRV), and videotaped facial actions] were collected thrice during a heel lance blood collection (baseline, lance, and recovery). After a feeding and nap, newborns were administered an abbreviated Brazelton Neonatal Behavioral Assessment Scale.

RESULTS

There were no between-group differences in maternal age, marital status, parity, gravidity, depression, anxiety, pregnancy smoking, maternal education, or infant gestational age at birth (all ps > 0.15). In both groups, HR increased with the heel lance and decreased during the postlance period. The alcohol-exposed group had lower mean HR than controls throughout, and showed no change in RSA over time. Cortisol levels showed no change over time in controls but decreased over time in exposed infants. Although facial action analyses revealed no group differences in response to the heel lance, behavioral responses assessed on the Brazelton Neonatal Scale showed less arousal in the exposed group.

CONCLUSIONS

Both cardiac autonomic and hypothalamic-pituitary-adrenal stress reactivity measures suggest a blunted response to an acute noxious event in alcohol-exposed newborns. This is supported by results on the Brazelton Neonatal Scale indicating reduced behavioral arousal in the exposed group. To our knowledge, these data provide the first biobehavioral examination of early pain reactivity in alcohol-exposed newborns and have important implications for understanding neuro-/biobehavioral effects of prenatal alcohol exposure in the newborn period.

Fetal effects of psychoactive drugs

Psychoactive drug use by pregnant women has the potential to effect fetal development; the effects are often thought to be drug-specific and gestational age dependent. This article describes the effects of three drugs with similar molecular targets that involve monoaminergic transmitter systems: cocaine, methamphetamine, and selective serotonin re-uptake inhibitors (SSRIs) used to treat maternal depression during pregnancy. We propose a possible common epigenetic mechanism for their potential effects on the developing child. We suggest that exposure to these substances acts as a stressor that affects fetal programming, disrupts fetal placental monoamine transporter expression and alters neuroendocrine and neurotransmitter system development. We also discuss neurobehavioral techniques that may be useful in the early detection of the effects of in utero drug exposure.

GREATER RIGHT FRONTAL EEG ASYMMETRY AND NONEMPHATHIC BEHAVIOR ARE OBSERVED IN CHILDREN PRENATALLY EXPOSED TO COCAINE

Responses to emotion-inducing stimuli were examined in 27, 3- to 6-year-old children, who were prenatally exposed to cocaine, and 27 unexposed controls. Children were monitored for EEG activity and their affect during an infant crying, simulated maternal distress, and a mildly frustrating task. Multivariate analyses indicated that the cocaine-exposed children had greater right frontal EEG asymmetry, showed fewer empathic reactions to a crying infant as well as to their own mothers, and they were less proficient in completing a cooperative task. These findings highlight the need for continued longitudinal research on the effects of early drug exposure for later socioemotional development.

Impaired regulation of arousal in 3-month-old infants exposed prenatally to cocaine and other drugs

This study investigated relations between drug exposure, particularly cocaine, and infants' regulation of arousal in response to novelty. Sixty-three infants — 36 cocaine exposed and 27 non-cocaine exposed — participated at 3 months of age in a novel-repeat stimulus presentation procedure. Arousal was operationalized in terms of infant behavioral state, affective expressiveness, and attention to the stimulus. Infants were tested and infant behaviors were scored by experimenters blind to the drug exposure status of the infant. There were no differences between the two groups in baseline behavioral state or affective expression before the presentation of novel stimuli. Compared to the non-cocaine-exposed group, infants exposed prenatally to cocaine and other drugs were more likely to exhibit a crying state and to display negative affect on novel stimulus presentations. There were no group differences in the amount of looking toward the stimulus. Both groups showed less crying and negative affect when stimuli were presented a second time, but decrements were consistently greater for the cocaine-exposed group. These results obtained when group differences were controlled for sociodemographic and perinatal variables. Sources of differences in the regulation of arousal in cocaine-exposed and non-cocainc-exposed infants are discussed, and impairments in the regulation of arousal in cocaine-exposed infants are considered in a framework of predictive implications for children's social and cognitive development.

Prenatal cocaine exposure and infant cortisol reactivity

This study examined the effects of prenatal cocaine exposure on infant hypothalamic-pituitary-adrenal axis activity and reactivity at 7 months of infant age. Participants were 168 caregiver-infant dyads (87 cocaine exposed, 81 not cocaine exposed; 47% boys). Maternal behavior, caregiving instability, and infant growth and behavior were assessed, and children's saliva was sampled before, during, and after standardized procedures designed to elicit emotional arousal. Results revealed cocaine-exposed infants had a high amplitude trajectory of cortisol reactivity compared to non-cocaine-exposed infants. Infant gender and caregiving instability moderated this association. The findings support a dual hazard vulnerability model and have implications for evolutionary-developmental theories of individual differences in biological sensitivity to context.

The association between prenatal exposure to cigarettes and cortisol reactivity and regulation in 7-month-old infants

We examined the association between prenatal exposure to cigarettes and adrenocortical responses to stress in 7-month-old infants. Cortisol levels were assessed twice prior to and twice following affect-eliciting procedures in 111 (59 exposed and 52 nonexposed) infants. Cortisol reactivity was defined as the difference between the peak poststressor cortisol level and the pretask cortisol level. Higher values indicated higher cortisol reactivity. Exposed infants had higher peak cortisol reactivity than nonexposed infants. There were no differences in pretask cortisol levels. Maternal hostility mediated the association between cigarette exposure and peak cortisol reactivity. Furthermore, infant gender moderated this association such that exposed boys had significantly higher peak cortisol reactivity than nonexposed infants or exposed girls. These findings provide additional evidence that prenatal cigarette exposure is associated with dysregulation during infancy and that early adverse, nonsocial experiences may have relatively long-lasting effects on cortisol reactivity in infants.

Autonomic alterations in cocaine-exposed neonates following orthostatic stress

We investigated the effects of prenatal cocaine exposure (PCE) on heart rate (HR) and heart rate variability (HRV) in the presence of orthostatic stress among near- and full-term neonates. PCE infants (n = 21) and controls (n = 23) were enrolled within 120 h of birth. ECG was recorded for an hour during quiet sleep, 30 min in supine position and then 30 min in an inclined position. Linear mixed models were used to analyze HR and HRV in the time domain and wavelet and power spectrum analyses in the frequency domain. PCE infants had tachycardia both before (p = 0.091) and after tilting (p = 0.015), but with a clear interaction between PCE and orthostatic stress (p = 0.049). Compared with controls, PCE infants had a delayed and prolonged reaction to orthostatic stress. There was also a pronounced interaction with regard to log-transformed SDDRR, a measure of HRV (p = 0.049). Controls experienced an instantaneous increase in log (SDDRR) followed by a prompt return to normal levels, while PCE infants had a gradual increase that did not dissipate quickly. Frequency-domain analyses also distinguished between the cocaine-exposed infants and the controls. Results suggest that the effects of PCE on the development of sympathetic and parasympathetic systems could lead to altered cardiovascular function.

The relation of ANS and HPA activation to infant anger and sadness response to goal blockage

This study examined the relation of anger and sadness to heart rate and cortisol in 4-month-old infants' (n = 56) response to a goal blockage. The blockage occurred during a contingency learning procedure where infants' response no longer produced a learned interesting event. Anger and sadness were the major emotional expressions to the blockage. The two emotional expressions were differentially related to heart rate and cortisol. Anger was related to increased heart rate, but not cortisol, whereas sadness was related to increased cortisol, but not heart rate. Along with other work, the present results support the view that infant anger in response to goal blockage involves autonomic as opposed to adrenocortical activation as a consequence of an expectation of control over the event. In contrast, sadness in response to goal blockage involves adrenocortical as opposed to autonomic activation stemming from the absence of an expectation of control.

Is a nappy change stressful to neonates?

OBJECTIVES

Infants in neonatal intensive care (NICU infants) are often cared for in a stressful environment that includes potentially painful or stressful interventions. The aim was to investigate whether NICU infants have different pattern of stress and pain responses than healthy newborns when challenged by a non-painful everyday care routine.

METHODS

NICU infants born at 23-38 weeks gestation (n=39) were compared to healthy full-term newborns (n=30). Cortisol concentrations in saliva were determined before and 30 min after a standardised nappy change. The premature infant pain profile (PIPP) and the neonatal infant pain scale (NIPS) were evaluated before, during, directly after, 3 min after, and 30 min after the nappy change. The investigation was performed on two different occasions, first between postnatal days 2-7 and then between postnatal days 10-18.

RESULTS

NICU infants had higher median baseline salivary cortisol levels compared to full-term newborns on both occasions (17.1 nmol/L vs. 6.2 nmol/L p<0.01 and 8.5 nmol/L vs. 2.4 nmol/L p<0.01, respectively). Salivary cortisol decreased in response to the second nappy change in NICU infants (p=0.01). NICU infants had higher PIPP scores during both nappy changes (p<0.001 for both occasions) and more sustained increases in PIPP and NIPS up to 30 min after the nappy changes compared to full-term newborns.

CONCLUSIONS

NICU infants have higher baseline salivary cortisol than healthy full-term newborns. There is a change in baseline cortisol by age in both groups. Full-term infants as well as NICU infants show an increased pain response to a standardised nappy change.

Reliability of salivary cortisol assessments in cocaine dependent individuals

The aim of this study was to assess the reliability of salivary cortisol as a measure of hypothalmic-pituitary-adrenal (HPA) axis function in cocaine dependent individuals. Saliva and total plasma samples were collected from 49 abusers on 3 testing days in the morning, across eight time points per day. Significant associations between saliva and plasma cortisol were observed across all time points collapsed across 3 days in both men and women. These moderately significant correlations suggest that salivary measurements represent a stable, non-invasive and broad indicator of HPA axis functioning in cocaine dependent individuals.

Glucocorticoid negative feedback in methadone-maintained former heroin addicts with ongoing cocaine dependence: dose-response to dexamethasone suppression

Combined cocaine and illicit opiate use is common. This study aimed to test the hypothesis that cocaine dependence in former heroin-addicted patients maintained on methadone treatment is associated with enhanced glucocorticoid negative feedback. Multiple dose dexamethasone suppression tests, using a conventional 2.0 mg dose, and two lower doses, 0.5 mg and 0.125 mg, were performed in 10 methadone-maintained former heroin addicts with ongoing cocaine dependence (C-MM), 10 stabilized methadone-maintained former heroin addicts with no ongoing drug or alcohol use (MM), and 22 normal volunteers (NV). At 9 hours, there was no difference in plasma adrenocorticotropin hormone (ACTH) and/or cortisol levels among groups on the baseline day, as well as after the two lower doses of dexamethasone. At 17 hours, C-MM and MM had significantly lower plasma ACTH and/or cortisol levels than NV. However, C-MM did not significantly differ from MM in their hormonal levels. When the hormonal responses to dexamethasone are expressed as magnitude of lowering from baseline, there was no significant difference at any dose among groups. Therefore, C-MM exhibited a normal glucocorticoid negative feedback in the morning. Using the standard interpretation of dexamethasone suppression testing based on the examination of the actual hormonal levels rather than the difference from baseline condition, C-MM appear to have glucocorticoid effects similar to MM, yet were both greater than NV in the late afternoon. Thus, further studies are needed to know whether altered glucocorticoid negative feedback is related to chronic cocaine exposure, or is the result of former heroin addiction and/or its long-term treatment with methadone.

Salivary cortisol and mood and pain profiles during skin-to-skin care for an unselected group of mothers and infants in neonatal intensive care

OBJECTIVES

Mother-infant separation after birth is a well-known source of stress. Parents and preterm infants in neonatal intensive care are separated immediately after birth. Skin-to-skin care is 1 possible method to reduce the separation-dependent stress. The aim of the present study was to investigate how skin-to-skin care influences stress for the mother and the infant in neonatal intensive care.

METHODS

Seventeen mother-infant pairs were included at their first and fourth skin-to-skin care. The infants were 25 to 33 weeks' gestational age, with birth weights ranging from 495 to 2590 g. In mothers, salivary cortisol, heart rate, mood scale, and stress measured on a visual analog scale (VAS) were analyzed. In infants, salivary cortisol and heart rate were analyzed, and because pain is one facet of stress, 2 different pain scales were used.

RESULTS

In mothers, the skin-to-skin care decreased salivary cortisol (32%), heart rate (7%), and VAS (89%), whereas mood increased (6%). Before the fourth skin-to-skin care, mothers rated less stress on VAS, and salivary cortisol and heart rate improved faster. The infants' cortisol either increased or decreased. Their heart rates and pain scores decreased during skin-to-skin care.

CONCLUSIONS

Our results lend additional support to the value of skin-to-skin care in neonatal intensive care. Variable stress responses in preterm infants favor the need for individualized care. The mothers' need for support seem to be more pronounced in the first skin-to-skin session as our results show a higher degree of stress as compared with later skin-to-skin care.

Event-related potentials in cocaine-exposed children during a Stroop task

OBJECTIVE

Prenatal cocaine-exposure may interfere with the ontogeny of prefrontal cortical executive functions due to cocaine's effect on the developing monoaminergic system. This study presents findings regarding cortical functioning in 29 prenatally cocaine-exposed (CE) and non-drug-exposed (NDE) 7- to 9-year-old children participating in event related potential (ERP) studies.

METHODS

ERPs were recorded using 128-electrode high-density arrays while children responded to a standard Stroop paradigm.

RESULTS

In the Stroop paradigm, CE children generated prolonged responses to the words while the NDE children produced briefer responses. Effects were noted in the region of the initial positive peak (P1), the second negative peak (N2) and the later positive peak (P3).

CONCLUSIONS

Early cocaine exposure may inhibit the specialization and streamlining of brain region involvement during cognitive processing such that task processing is slower to begin, requires more diverse cortical involvement, and requires more time to complete. ERP methodology has considerable potential for studying frontal maturation and may provide additional information to clarify generally the specific effects of prenatal CE on cortical functioning and the developmental course of cognitive functions.

Infant emotional and cortisol responses to goal blockage

This study examined the relation of infant emotional responses of anger and sadness to cortisol response in 2 goal blockage situations. One goal blockage with 4-month-old infants (N = 56) involved a contingency learning procedure where infants' learned response was no longer effective in reinstating an event. The other goal blockage with 6-month-old infants (N = 84) involved the still face procedure where infants' reactions to their mothers' lack of responsivity were not effective in reestablishing interaction. For both blockages, sadness was related to cortisol response, though anger was not--the greater the sadness, the higher the cortisol response. This differential relation is consistent with other evidence indicating the more positive role of anger as opposed to sadness in overcoming an obstacle.

Repeated psychological stress testing in stimulant-dependent patients

Decreasing response to stress has been one goal of interventions aimed at reducing relapse to substances of abuse. A laboratory stress test that can be repeated would be helpful in testing the efficacy of interventions in decreasing the response to stress before more extensive trials are begun. The effects of two types of psychological stress tests, the Trier Social Stress Test (TSST) and a stress imagery test, on psychological, physiological, and hormonal responses (salivary cortisol and DHEA) were examined when each test was given twice to cocaine- or methamphetamine-dependent human subjects, 24 of whom completed at least one session. The stress imagery test produced significant changes in several of the subjective response measures in both first and second sessions, including several measures of negative affect and a craving measure. The TSST produced significant changes only in the second session. The stress imagery protocol showed better replicability across two sessions. Cocaine users and methamphetamine users did not respond similarly in their craving responses. Reported craving for methamphetamine after stress testing showed decreases or much smaller increases compared to that for cocaine. Neither stress test significantly increased salivary cortisol or DHEA, and changes in hormone concentrations were not related to subjective responses. These results suggest that stress imagery testing procedures may be useful as provocative tests of stress-induced affect and stimulant drug craving. Although less convincing because of the heterogeneity of the subjects, they also suggest that HPA axis responsivity is not clearly linked to acute stress-induced stimulant craving or affective response.

Effects of prenatal betamethasone exposure on regulation of stress physiology in healthy premature infants

The objective of this study was to examine the effects of prenatal exposure to betamethasone, a corticosteroid, on postnatal stress regulation, particularly activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Effects were assessed by measuring salivary cortisol production at baseline and in response to two potentially stressful events, a heel-stick blood draw and a physical exam, in infants born at 33-34 weeks gestation. Subjects included 9 infants with antenatal betamethasone treatment (2 doses of 12 mg of betamethasone administered intramuscularly to the mother twelve hours apart) and 9 infants without such treatment. Testing took place 3-6 days after delivery. Measures of behavioral distress confirmed that both events were stressful to these premature infants. Infants with betamethasone exposure, however, failed to exhibit increases in cortisol to either stressor. In contrast, infants without betamethasone exposure displayed elevated cortisol to the heel-stick blood draw but not the physical exam. These findings suggest that antenatal corticosteroids suppress infants' HPA response to a stressor typically encountered in a neonatal intensive care situation.