Childhood neurodevelopment after prescription of maintenance methadone for opioid dependency in pregnancy: a systematic review and meta-analysis

Association of Postnatal Opioid Exposure and 2-Year Neurodevelopmental Outcomes in Infants Undergoing Cardiac Surgery

BACKGROUND

Opioids are commonly used to provide analgesia during and after congenital heart surgery. The effects of exposure to opioids on neurodevelopment in neonates and infants are not well understood.

OBJECTIVES

This study sought to evaluate the associations between cumulative opioid exposure (measured in morphine mg equivalent) over the first year of life and 2-year neurodevelopmental outcomes (Bayley Scales of Infant and Toddler Development-Third/Fourth Edition [Bayley-III/IV] cognitive, language, and motor scores).

METHODS

A single-center retrospective cohort study of infants undergoing congenital heart surgery was performed. Adjustment for measurable confounders was performed through multivariable linear regression.

RESULTS

A total of 526 subjects were studied, of whom 32% underwent Society for Thoracic Surgeons-European Association for Cardio-Thoracic Surgery category 4 or 5 operations. In unadjusted analyses, higher total exposure to opioids was associated with worse scores across all 3 Bayley-III/IV domain scores (all P < 0.05). After adjustment for measured confounders, greater opioid exposure was associated with lower Bayley-III/IV scores (cognitive: β = -1.0 per log-transformed morphine mg equivalents, P = 0.04; language: β = -1.2, P = 0.04; and motor: β = -1.1, P = 0.02). Total hospital length of stay, prematurity, genetic syndromes, and worse neighborhood socioeconomic status (represented either by Social Vulnerability Index or Childhood Opportunity Index) were all associated with worse Bayley-III/IV scores across all domains (all P < 0.05).

CONCLUSIONS

Greater postnatal exposure to opioids was associated with worse neurodevelopmental outcomes across cognitive, language, and motor domains, independent of other less modifiable factors. This finding should motivate research and efforts to explore reduction in opioid exposure while preserving quality cardiac intensive care.

Effects of prenatal exposure to methadone or buprenorphine and maternal separation on anxiety-like behavior in rats

BACKGROUND

The use of medications for opioid use disorder such as methadone or buprenorphine is increasing among pregnant women. However, long-term effects of this treatment on the children's health are not well understood. A key challenge is distinguishing the effects of opioid exposure from other confounding factors associated with human opioid use, such as reduced maternal care. In this study, we therefore used a multi-risk factor design to examine anxiety-like behavior in rats prenatally exposed to methadone or buprenorphine, with or without maternal separation the first two weeks after birth.

METHODS

Female Sprague Dawley rats were exposed to methadone (10mg/kg/day), buprenorphine (1mg/kg/day) or sterile water throughout gestation. Half of the offspring in each litter experienced maternal separation for 3h per day from postnatal day 2 to 12. Male and female offspring (6-9 weeks) were tested in the open field, light-dark transition and elevated plus maze tests to assess anxiety-like behavior.

RESULTS

Offspring exposed to buprenorphine and not subjected to maternal separation displayed increased anxiety-like behavior in 3 out of 6 outcomes in the light-dark transition and elevated plus maze tests. Maternal separation did not exacerbate, but rather diminished this behavior. Males and females responded differently to methadone, with a trend towards reduced anxiety for males and increased anxiety for females.

CONCLUSIONS

Prenatal exposure to methadone or buprenorphine may increase the risk of developing anxiety-like behavior later in life, but the effect depends on specific subgroup characteristics. Further research is required to draw definitive conclusions.

Ultrasound evaluation of brain parenchyma in preterm infants with prenatal opioid exposure

OBJECTIVE

To evaluate whether preterm infants with prenatal opioid exposure had differences in brain size on head ultrasounds (HUS) in comparison to non-exposed infants.

STUDY DESIGN

Preterm infants ≤34 weeks with prenatal opioid exposure (n = 47) and matched non-exposed infants (n = 62) with early HUSs were examined. Fifteen brain measurements were made and linear regression models performed to evaluate differences.

RESULTS

Brain measurements were smaller in the right ventricular index [β = -0.18 mm (95% CI -0.32, -0.03]), left ventricular index [β = -0.04 mm (95% CI -0.08, -0.003)], left basal ganglia insula [β = -0.10 mm (95% CI -0.15, -0.04)], right basal ganglia insula [β = -0.08 mm (95% CI -0.14, -0.03)], corpus callosum fastigium length [β = -0.16 mm (95% CI -0.25, -0.06)], intracranial height index [β = -0.31 mm (95% CI -0.44, -0.18)], and transcerebellar measurements [β = -0.13 (95% CI -0.25, -0.02)] in the opioid-exposed group.

CONCLUSIONS

Preterm infants with prenatal opioid exposure have smaller brain sizes compared to non-exposed infants, potentially increasing their risk for neurodevelopmental abnormalities.

Methadone directly impairs central nervous system cells in vitro

Methadone is a synthetic long-acting opioid that is increasingly used in the replacement therapy of opioid-addicted patients, including pregnant women. However, methadone therapy in this population poses challenges, as it induces cognitive and behavioral impairments in infants exposed to this opioid during prenatal development. In animal models, prenatal methadone exposure results in detrimental consequences to the central nervous system, such as: (i) increased neuronal apoptosis; (ii) disruption of oligodendrocyte maturation and increased apoptosis and (iii) increased microglia and astrocyte activation. However, it remains unclear whether these deleterious effects result from a direct effect of methadone on brain cells. Therefore, our goal was to uncover the impact of methadone on single brain cell types in vitro. Primary cultures of rat neurons, oligodendrocytes, microglia, and astrocytes were treated for three days with 10 µM methadone to emulate a chronic administration. Apoptotic neurons were identified by cleaved caspase-3 detection, and synaptic density was assessed by the juxtaposition of presynaptic and postsynaptic markers. Apoptosis of oligodendrocyte precursors was determined by cleaved caspase-3 detection. Oligodendrocyte myelination was assessed by immunofluorescence, while microglia and astrocyte proinflammatory activation were assessed by both immunofluorescence and RT-qPCR. Methadone treatment increased neuronal apoptosis and reduced synaptic density. Furthermore, it led to increased oligodendrocyte apoptosis and a reduction in the myelinating capacity of these cells, and promoted the proinflammatory activation of microglia and astrocytes. We showed that methadone, the most widely used drug in opioid replacement therapy for pregnant women with opioid addiction, directly impairs brain cells in vitro, highlighting the need for developing alternative therapies to address opioid addiction in this population.

Associations between social adversity, caregiver psychological factors, and language outcomes in 9.5-year-old children born to women with opioid use disorder

We describe the language ability of children at age 9.5 years who were born to women with an opioid use disorder and examine the associations between prenatal opioid exposure, sex, social adversity, caregiver psychological factors, and child language. Data were drawn from the regional prospective longitudinal Canterbury Methadone in Pregnancy study. At the 9.5-year wave, 80 children who were born to mothers in Methadone Maintenance Treatment and their caregivers, and 98 non-exposed comparison children were assessed using a comprehensive standardized measure of language. Information related to social adversity and caregiver psychological factors was obtained from comprehensive caregiver interviews. At age 9.5 years, opioid-exposed children had lower language scores than the non-exposed children, however their group average was within the normal range on the CELF-4 norms. A series of multivariate hierarchical regression models predicting low language at 9.5 years showed sex and opioid-exposure status predicted low language in the first step. The addition of social adversity factors significantly improved the model. The further addition of caregiver psychological factors did not improve prediction. Only sex was a significant predictor throughout. In this sample, children prenatally exposed to opioids were at higher risk of low language outcomes. However, the child being male and social adversity were important influencing factors. This suggests early language support services are indicated for opioid-exposed children, particularly boys and those in socially adverse circumstances.

Children had increased risks of impaired motor and visual-motor skills after prenatal exposure to opioid maintenance therapy

AIM

Preschool children prenatally exposed to opioid maintenance therapy (OMT) have an increased risk of neurodevelopmental impairments. We aimed to investigate long-term motor and visual-motor integration outcome in children aged 5-13 Years, born to mothers in OMT.

METHODS

From January 2018 to June 2021, 63 children prenatally exposed to OMT and 63 comparison children matched for age and gender, were examined at two Norwegian hospitals. Motor skills were assessed by the Movement-ABC test and visual-motor integration by the Beery VMI test. A motor function neurological assessment test was used to examine neuromotor soft signs.

RESULTS

In the OMT-exposed group, 16% had motor impairment, 35% had motor problems and 19% had visual-motor integration problems. Forty-three percent of the exposed children had neuromotor soft signs. Strabismus had some influence on motor and visual-motor outcomes but could not explain the group differences.

CONCLUSION

Children prenatally exposed to opioid maintenance therapy have an increased risk of long-term motor impairment and visual-motor problems. In addition, they exhibit significantly more neuromotor soft signs, which may affect general well-being, leisure activities and school performance.

Prenatal opioid exposure by likelihood of exposure and risk to prenatal development: Medicaid-covered births in Wisconsin, 2010-2019

Prenatal opioid exposure is an established public health problem, in particular among Medicaid-covered births. Yet, existing prevalence rates are plausibly underestimated. We leverage extensive linked longitudinal administrative data for all Medicaid-covered live births in Wisconsin from 2010 to 2019 to estimate a range of prevalence rates using an innovative strategy that jointly accounts for both likelihood of exposure and potential risk to prenatal development. We find that 20.8% of infants may have been prenatally exposed to opioids, with 1.7% diagnosed with neonatal abstinence syndrome and an additional 1.2% having a high combined likelihood of exposure and potential risk to prenatal development, 2.6% a moderate combined likelihood and risk, and 15.3% a low or uncertain combined likelihood and risk. We assess improvements in prevalence estimates based on our nuanced classification relative to those of prior studies. Our strategy could be broadly used to quantify the scope of the opioid crisis for pregnant populations, target interventions, and promote child health and development.

Antenatal care of women who use opioids: a qualitative study of practitioners' perceptions of strengths and challenges of current service provision in Scotland

BACKGROUND

The increasing rise of women using opioids during pregnancy across the world has warranted concern over the access and quality of antenatal care received by this group. Scotland has particularly high levels of opioid use, and correspondingly, pregnancies involving women who use opioids. The purpose of this study was to investigate the different models of antenatal care for women using opioids during pregnancy in three Scottish Health Board Areas, and to explore multi-disciplinary practitioners' perceptions of the strengths and challenges of working with women who use opioids through these specialist services.

METHODS

Thirteen semi-structured interviews were conducted with health and social care workers who had experience of providing antenatal and postnatal care to women who use drugs across three Scottish Health Board Areas: NHS Greater Glasgow and Clyde, NHS Lothian, and NHS Tayside. Framework Analysis was used to analyse interview data. The five stages of framework analysis were undertaken: familiarisation, identifying the thematic framework, indexing, charting, and mapping and interpretation.

RESULTS

Each area had a specialist antenatal pathway for women who used substances. Pathways varied, with some consisting of specialist midwives, and others comprising a multidisciplinary team (e.g. midwife, mental health nurse, social workers, and an obstetrician). Referral criteria for the specialist service differed between health board areas. These specialised pathways presented several key strengths: continuity of care with one midwife and a strong patient-practitioner relationship; increased number of appointments, support and scans; and highly specialised healthcare professionals with experience of working with substance use. In spite of this, there were a number of limitations to these pathways: a lack of additional psychological support for the mother; some staff not having the skills to engage with the complexity of patients who use substances; and problems with patient engagement.

CONCLUSIONS

Across the three areas, there appears to be high-quality multi-disciplinary antenatal services for women who use opioids during pregnancy. However, referral criteria vary and some services appear more comprehensive than others. Further research is needed into the perceptions of women who use opioids on facilitators and barriers to antenatal care, and provision in rural regions of Scotland.

Opioid-induced dysbiosis of maternal gut microbiota during gestation alters offspring gut microbiota and pain sensitivity

There has been a rapid increase in neonates born with a history of prenatal opioid exposure. How prenatal opioid exposure affects pain sensitivity in offspring is of interest, as this may perpetuate the opioid epidemic. While few studies have reported hypersensitivity to thermal pain, potential mechanisms have not been described. This study posits that alterations in the gut microbiome may underly hypersensitivity to pain in prenatally methadone-exposed 3-week-old male offspring, which were generated using a mouse model of prenatal methadone exposure. Fecal samples collected from dams and their offspring were subjected to 16s rRNA sequencing. Thermal and mechanical pain were assessed using the tail flick and Von Frey assays. Transcriptomic changes in whole brain samples of opioid or saline-exposed offspring were investigated using RNA-sequencing, and midbrain sections from these animals were subjected to qPCR profiling of genes related to neuropathic and inflammatory pain pathways. Prenatal methadone exposure increased sensitivity to thermal and mechanical pain and elevated serum levels of IL-17a. Taxonomical analysis revealed that prenatal methadone exposure resulted in significant alterations in fecal gut microbiota composition, including depletion of Lactobacillus, Bifidobacterium, and Lachnospiracea sp and increased relative abundance of Akkermansia, Clostridium sensu stricto 1, and Lachnoclostridium. Supplementation of the probiotic VSL#3 in dams rescued hypersensitivity to thermal and mechanical pain in prenatally methadone-exposed offspring. Similarly, cross-fostering prenatally methadone-exposed offspring to control dams also attenuated hypersensitivity to thermal pain in opioid-exposed offspring. Modulation of the maternal and neonatal gut microbiome with probiotics resulted in transcriptional changes in genes related to neuropathic and immune-related signaling in whole brain and midbrain samples of prenatally methadone-exposed offspring. Together, our work provides compelling evidence of the gut-brain-axis in mediating pain sensitivity in prenatally opioid-exposed offspring.

Impaired vision in children prenatally exposed to methadone: an observational cohort study

BACKGROUND/OBJECTIVES

To examine prevalence of failed visual assessment at 8-10 years in children born to methadone-maintained opioid dependent (MMOD) mothers and relate this to known in utero substance exposure.

SUBJECTS/METHODS

Follow up of observational cohort study of methadone-exposed and comparison children matched for birthweight, gestation and postcode of residence at birth. Participants were 144 children (98 exposed, 46 comparison). Prenatal drug exposure was previously established via comprehensive maternal and neonatal toxicology. Children were invited to attend for visual assessment and casenotes were reviewed. Presence of acuity poorer than 0.2 logMAR, strabismus, nystagmus and/or impaired stereovision constituted a 'fail'. Fail rates were compared between methadone-exposed and comparison children after adjusting for known confounding variables.

RESULTS

33 children attended in person: data were also derived from casenote review for all children. After controlling for maternal reported tobacco use, methadone-exposed children were more likely to have a visual 'fail' outcome, adjusted odds ratio 2.6, 95% CI 1.1-6.2; adjusted relative risk 1.8 (95% CI 1.1-3.4). Visual 'fail' outcome rates did not differ between methadone-exposed children who had (n = 47) or had not (n = 51) received pharmacological treatment for neonatal abstinence/opioid withdrawal syndrome (NAS/NOWS); fail rate 62% vs 53% (95% CI of difference-11-27%).

CONCLUSIONS

Children born to MMOD mothers are almost twice as likely as unexposed peers to have significant visual abnormalities at primary school age. Prenatal methadone exposure should be considered in the differential diagnosis of nystagmus. Findings support visual assessment prior to school entry for children with any history of prenatal opioid exposure.

TRIAL REGISTRATION

The study was prospectively registered on ClinicalTrials.gov (NCT03603301), https://clinicaltrials.gov/ct2/show/NCT03603301 .

Long-Term Visual and Neurodevelopmental Outcomes in Two Children with Congenital Nystagmus Secondary to Methadone Exposure In utero

Methadone is used as a substitute for illicit opioids during pregnancy. However, the real effect of this molecule on visual and neurodevelopmental outcomes of the children exposed is not fully understood, since studies considered subjects born to polydrug-dependent mothers and followed for few months/years. We report the long-term outcomes of two infants with congenital nystagmus solely exposed to methadone in utero. Neurological and neurovisual evaluations were performed every year from the first year of life to 11 years of age. One child was diagnosed with developmental coordination disorder. Both cases presented with ophthalmologic (refractive errors), oculomotor (nystagmus and fixation, smooth pursuit, and saccades dysfunctions), and perceptive problems (reduced visual acuity and contrast sensitivity). While nystagmus and other oculomotor dysfunctions remained stable over time, visual acuity and contrast sensitivity improved; refractive errors worsened and required corrective lenses. Both children showed normal neurodevelopmental and cognitive profile. This report highlights the long-term visual and developmental outcomes of two children exclusively exposed to methadone underlining the possibility of a visual dysfunction and motor coordination disorder. These observations prompt the need to investigate prenatal drug exposure as a cause of congenital nystagmus.

Developmental implications of prenatal opioid exposure among school-aged children: a mixed methods and community-initiated analysis

BACKGROUND

Growing research points to potential long-term developmental implications of prenatal opioid exposure for children. Yet, polysubstance use and adverse childhood experiences are raised as potential confounders. Further, there is a lack of data on school-age children and the children's strengths.

METHODS

Parents and caregivers of children with prenatal opioid exposure worked with the study team to design, collect, and descriptively analyze mixed method data. Data were collected through survey (n = 148) and two focus groups (n = 15) from a convenience sample in mostly West Virginia and Massachusetts.

RESULTS

Nearly half of the children in the sample were diagnosed with multiple developmental delays, behavioral health conditions, and specific learning disorders. Roughly 85% of children have behavioral challenges. Associations between prenatal opioid exposure and negative developmental outcomes did not vary by type of opioid nor by polysubstance use, while controlling for adverse childhood experiences. Importantly, over 80% of families also reported their child's strengths, including empathy, social magnetism, and their resilience.

CONCLUSIONS

The challenges for children born with prenatal opioid exposure may extend into school-age. The results are consistent with prior research on younger children, suggesting a need for best practices for caring for these children beyond the neonatal stage.

Outcomes of Babies with Opioid Exposure (OBOE): protocol of a prospective longitudinal cohort study

BACKGROUND

While the health, social, and economic impacts of opioid addiction on adults and their communities are well known, the impact of maternal opioid use on the fetus exposed in utero is less well understood.

METHODS

This paper presents the protocol of the ACT NOW Outcomes of Babies with Opioid Exposure (OBOE) Study, a multi-site prospective longitudinal cohort study of infants with antenatal opioid exposure and unexposed controls. Study objectives are to determine the impact of antenatal opioid exposure on brain development and neurodevelopmental outcomes over the first 2 years of life and explore whether family, home, and community factors modify developmental trajectories during this critical time period.

RESULTS

Primary outcomes related to brain development include cortical volumes, deep cerebral gray matter volumes, resting-state functional connectivity measures, and structural connectivity measures using diffusion tensor imaging. Primary neurodevelopmental outcomes include visual abnormalities, cognitive, language, and motor skills measured using the Bayley Scales of Infant Development and social-emotional and behavioral problems and competence measured by the Brief Infant-Toddler Social and Emotional Assessment.

CONCLUSIONS

The OBOE study has been designed to overcome challenges of previous studies and will help further understanding of the effects of antenatal opioid exposure on early infant development.

IMPACT

This study will integrate MRI findings and comprehensive neurodevelopmental assessments to provide early insights into the functional topography of the brain in this high-risk population and assess MRI as a potential biomarker. Rather than conducting neuroimaging at a single time point, the study will include serial MRI assessments from birth to 2 years, allowing for the examination of trajectories throughout this period of rapid brain development. While previous studies often have had limited information on exposures, this study will use umbilical cord assays to accurately measure amounts of opioids and other substances from 20 weeks of gestation to birth.

In utero methadone exposure permanently alters anatomical and functional connectivity: A preclinical evaluation

The opioid epidemic is an ongoing public health crisis, and children born following prenatal opioid exposure (POE) have increased risk of long-term cognitive and behavioral sequelae. Clinical studies have identified reduced gray matter volume and abnormal white matter microstructure in children with POE but impacts on whole-brain functional brain connectivity (FC) have not been reported. To define effects of POE on whole brain FC and white matter injury in adult animals, we performed quantitative whole-brain structural and functional MRI. We used an established rat model of POE in which we have previously reported impaired executive function in adult rats analogous to persistent neurocognitive symptoms described in humans with POE. Pregnant Sprague-Dawley rat dams received continuous methadone (12 mg/kg/day) vs. saline infusion for 28 days via osmotic mini-pumps, exposing rats to pre- and postnatal opioid until weaning. At young adult age (P60), POE and saline exposed offspring underwent in vivo MRI included diffusion tensor imaging and functional MRI (fMRI). Results indicate that fractional anisotropy (FA) was decreased in adult animals with POE [n = 11] compared to animals that received saline [n = 9] in major white matter tracts, including the corpus callosum (p < 0.001) and external capsule (p < 0.01). This change in FA was concomitant with reduced axial diffusivity in the external capsule (p < 0.01) and increased radial diffusivity in the corpus callosum (p < 0.01). fMRI analyses reveal brainwide FC was diffusely lower in POE (p < 10-6; 10% of variance explained by group). Decreased connectivity in cortical-cortical and cortico-basal ganglia circuitry was particularly prominent with large effect sizes (Glass's Δ > 1). Taken together, these data confirm POE reduces brainwide functional connectivity as well as microstructural integrity of major white matter tracts. Altered neural circuitry, dysregulated network refinement, and diffuse network dysfunction have been implicated in executive function deficits that are common in children with POE. FC may serve as a translatable biomarker in children with POE.

Opioid Use in Pregnancy: A Review

Importance

The use and misuse of opioids in pregnancy have been increasing and are a major public health issue. Opioid use in pregnancy and during lactation has been associated with increased maternal and neonatal morbidity and mortality.

Objective

This review aims to summarize the existing literature and current recommendations for opioid use while pregnant or lactating.

Evidence Acquisition

A PubMed, Cochrane Library, and Google Scholar literature search using the following terms was performed to gather relevant data: "opioids," "opioid maintenance therapy," "opioid use disorder," "suboxone," "buprenorphine," "methadone," "medication for opioid use disorder," "fetal outcomes," "perinatal outcomes," "pregnancy," "lactation," and "neonatal abstinence syndrome."

Results

Available studies on opioid use in pregnancy and during lactation were reviewed and support association with increased odds of maternal death, placental insufficiency, cardiac arrest, preterm birth, neonatal intensive care unit admission, low birth weight, and small for gestational age infants. Studies were also reviewed on pharmacotherapy options in pregnancy and promising prenatal care models.

Conclusion and Relevance

There is a critical need for research on the effects of opioid use and related pharmacotherapy options in pregnancy. Once the adverse perinatal effects of opioid exposure are identified and well-characterized, patient education, intervention, and antenatal surveillance can be developed to predict and mitigate its impact on maternal and fetal health.

Prenatal Opioid Exposure and Neurodevelopmental Outcomes

The opioid epidemic in the United States has resulted in a significant increase in opioid use disorder among pregnant women and a concomitant increase in the incidence of neonatal opioid withdrawal syndrome. The long-term consequences of prenatal opioid exposure on neurodevelopmental outcomes are not fully understood. Animal studies indicate increased neuronal apoptosis and decreased neuronal proliferation and myelination with opioid exposure in-utero. Meta-analyses of human studies suggest decreased cognition and psychomotor performance in infancy and deficits in cognition and language in preschool. However, current studies have primarily focused on heroin or methadone exposure and have been limited by small sample size, inadequate comparison groups, and the inability to account for additional risk factors and exposures such as polysubstance abuse, poor prenatal care, neonatal withdrawal and treatment with opioids, and unsupportive home environment. Future studies should aim to better understand the potential impact of these confounding factors on the neurodevelopmental trajectory of exposed infants. This review discusses the up-to-date literature, current gaps in knowledge, and considerations for future studies in the arena of prenatal opioid exposure and neurodevelopmental outcomes.

Executive functioning, behavioural, emotional, and cognitive difficulties in school-aged children prenatally exposed to methadone

Aim

The aim of this study was to examine executive function and emotional and behavioural difficulties of children aged between 8 and 10 years who had been prenatally exposed to methadone, compared to non-exposed peers.

Methods

Prospective study: third follow-up of an original cohort of 153 children born to methadone-maintained opioid-dependent mothers 2008-2010: previous investigations were at 1-3 days and at 6-7 months of age. Carers completed the Strength and Difficulties Questionnaire (SDQ) and the Behaviour Rating Inventory of Executive Function, Second Edition (BRIEF®2). Results were compared between exposed and non-exposed groups.

Results

Carers of 33 of 144 traceable children completed the measures. SDQ responses showed no group differences on subscales of emotional symptoms, conduct problems, or peer relationship problems. A marginally higher proportion of exposed children had a high or very high hyperactivity subscale score. Exposed children scored significantly higher on BRIEF®2 behavioural, emotional, and cognitive regulation indices, and on the global executive composite. After controlling for potentially confounding higher reported maternal tobacco use in the exposed group via regression modelling, the effect of methadone exposure reduced.

Interpretation

This study supports evidence that methadone exposure in utero is associated with adverse neurodevelopmental outcomes in childhood. Challenges in studying this population include difficulties with long-term follow-up and controlling for potentially confounding factors. Further investigation of the safety of methadone and other opioids in pregnancy must include consideration of maternal tobacco use.

Methadone alters the peripheral inflammatory and central immune landscape following prenatal exposure in rats

Opioid use during pregnancy continues to rise at alarming rates with a parallel trend in the number of infants and children exposed to opioid medications each year. Prenatal opioid exposure (POE) occurs at a critical timepoint in neurodevelopment disrupting intricate pathways essential for neural-immune maturation with the potential for devastating long-term consequences. Understanding the mechanisms underlying injury associated with POE is essential to address long-term outcomes and identify diagnostic and therapeutic biomarkers in this vulnerable patient population. Using an established preclinical model of POE, we investigated changes in cerebral and peripheral inflammation and peripheral blood mononuclear cell (PBMC) activity. We hypothesized that neuroinflammation, as defined by changes in specific cerebral immune cell populations, would exist in adult rats following POE concomitant with sustained peripheral immune hyperreactivity (SPIHR). Our data demonstrated alterations in cerebral immune cells at postnatal day 60 (P60) typified by increased regulatory T cells (p < 0.01) and neutrophils (p < 0.05) in rats with POE compared to controls. Evaluation of serum revealed increased levels of IL-6 (p < 0.05) and CXCL1 (p < 0.05) at P21 in rats with POE compared to controls with no significant difference in cytokine or chemokine levels between the two groups at P60. Additionally, PBMCs isolated from rats with POE at P21 demonstrated baseline hypersecretion of IL-6 (p < 0.01) and SPIHR with increased levels of TNF-α (p < 0.05) and CXCL1 (p < 0.05) following stimulation with LPS. At P60, however, there was no significant difference found in cytokine or chemokine levels secreted by PBMCs isolated from rats with POE at baseline or with LPS stimulation when compared to controls. Taken together, these data demonstrate cerebral inflammation months after prenatal opioid exposure and long after the resolution of systemic inflammation and SPIHR seen at toddler age equivalent. Chronic alterations in the cerebral immune cell populations secondary to prenatal opioid exposure may underly long-term consequences of developmental brain injury including deficits in cognition and attention. These findings may be invaluable to further investigations of precise biomarkers of injury and targeted therapeutics for this vulnerable population.

One-Year Neurodevelopmental Outcomes After Neonatal Opioid Withdrawal Syndrome: A Prospective Cohort Study

Purpose

The aims of this study were, in a cohort of children with neonatal opioid withdrawal syndrome (NOWS), (a) to report 1-year neurodevelopmental outcomes and specifically characterize speech, language, and hearing outcomes and (b) to report the prevalence of cleft lip and/or cleft palate.

Method

This prospective observational cohort study includes newborns with confirmed in utero opioid exposure who received pharmacological treatment for NOWS. During 1-year-old developmental visits, we administered standardized assessments (Bayley Scales of Infant and Toddler Development-Third Edition [Bayley-III] or Developmental Assessment of Young Children-Second Edition [DAYC-2]-due to COVID-19 restrictions). We compared Bayley-III scores to standardized population means using one-sample z tests. We report estimates, 95% confidence intervals, and two-sided p values.

Results

We enrolled 202 infants (October 2018 to March 2020). Follow-up at 1-year was 80%. Infants with NOWS had lower Bayley-III scores at 1 year compared to published norms for cognitive, language, and motor domains. One infant with NOWS was diagnosed with isolated cleft palate and Pierre Robin sequence. All infants passed the newborn hearing screen, and 7.5% had a formal hearing evaluation after neonatal intensive care unit discharge, with 40% having abnormal or inconclusive results; middle ear effusion was the leading cause of abnormal hearing (66.7%). Ten percent of children received a speech-language pathology referral prior to 2 years of age. Infants born to mothers with mental health conditions were more likely to have Bayley-III or DAYC-2 scores below 95 in language or motor domains.

Conclusions

Infants with pharmacologically treated NOWS have significantly lower cognitive, language, and motor scores on standardized developmental testing compared to population means at 1 year of age. Early speech-language pathology referral is frequently necessary to promote optimal development in this population.

Supplemental Material

https://doi.org/10.23641/asha.20044403.

Cerebral perfusion and neurological examination characterise neonatal opioid withdrawal syndrome: a prospective cohort study

OBJECTIVE

To test the hypothesis that cerebral blood flow (CBF) assessed with arterial spin labelling (ASL) MRI is increased and standardised neurological examination is altered in infants with neonatal opioid withdrawal syndrome (NOWS) compared with those without.

DESIGN

Prospective cohort study.

SETTING

Level IV neonatal intensive care unit and outpatient primary care centre.

PARTICIPANTS

Infants with NOWS receiving pharmacological treatment and unexposed controls matched for gestational age at birth and post-menstrual age at MRI.

MAIN OUTCOMES

CBF assessed by ASL on non-sedated 3-Tesla MRI and standardised Hammersmith Neonatal Neurological Examination (HNNE) within 14 days of birth.

RESULTS

Thirty infants with NOWS and 31 control infants were enrolled and included in the final analysis. Global CBF across the brain was higher in the NOWS group compared with controls (14.2 mL/100 g/min±5.5 vs 10.7 mL/100 g/min±4.3, mean±SD, Cohen's d=0.72). HNNE total optimality score was lower in the NOWS group compared with controls (25.9±3.6 vs 28.4±2.4, mean±SD, Cohen's d=0.81). A penalised logistic regression model including both CBF and HNNE items discriminated best between the two groups.

CONCLUSIONS

Increased cerebral perfusion and neurological examination abnormalities characterise infants with NOWS compared with those without intrauterine drug exposure and suggest prenatal substance exposure affects fetal brain development. Identifying neurological and neuroimaging characteristics of infants with NOWS can contribute to understanding mechanisms underlying later outcomes and to designing potential new treatments.

Role of Brain Modulators in Neurodevelopment: Focus on Autism Spectrum Disorder and Associated Comorbidities

Autism spectrum disorder (ASD) and associated neurodevelopmental disorders share similar pathogenesis and clinical features. Pathophysiological changes in these diseases are rooted in early neuronal stem cells in the uterus. Several genetic and environmental factors potentially perturb neurogenesis and synaptogenesis processes causing incomplete or altered maturation of the brain that precedes the symptomology later in life. In this review, the impact of several endogenous neuromodulators and pharmacological agents on the foetus during pregnancy, manifested on numerous aspects of neurodevelopment is discussed. Within this context, some possible insults that may alter these modulators and therefore alter their role in neurodevelopment are high-lighted. Sometimes, a particular insult could influence several neuromodulator systems as is supported by recent research in the field of ASD and associated disorders. Dopaminergic hy-pothesis prevailed on the table for discussion of the pathogenesis of schizophrenia (SCH), atten-tion-deficit hyperactivity disorder (ADHD) and ASD for a long time. However, recent cumulative evidence suggests otherwise. Indeed, the neuromodulators that are dysregulated in ASD and comorbid disorders are as diverse as the causes and symptoms of this disease. Additionally, these neuromodulators have roles in brain development, further complicating their involvement in comorbidity. This review will survey the current understanding of the neuromodulating systems to serve the pharmacological field during pregnancy and to minimize drug-related insults in pa-tients with ASD and associated comorbidity disorders, e.g., SCH or ADHD.

Neural alterations in opioid-exposed infants revealed by edge-centric brain functional networks

Prenatal opioid exposure has been linked to adverse effects spanning multiple neurodevelopmental domains, including cognition, motor development, attention, and vision. However, the neural basis of these abnormalities is largely unknown. A total of 49 infants, including 21 opioid-exposed and 28 controls, were enrolled and underwent MRI (43 ± 6 days old) after birth, including resting state functional MRI. Edge-centric functional networks based on dynamic functional connections were constructed, and machine-learning methods were employed to identify neural features distinguishing opioid-exposed infants from unexposed controls. An accuracy of 73.6% (sensitivity 76.25% and specificity 69.33%) was achieved using 10 times 10-fold cross-validation, which substantially outperformed those obtained using conventional static functional connections (accuracy 56.9%). More importantly, we identified that prenatal opioid exposure preferentially affects inter- rather than intra-network dynamic functional connections, particularly with the visual, subcortical, and default mode networks. Consistent results at the brain regional and connection levels were also observed, where the brain regions and connections associated with visual and higher order cognitive functions played pivotal roles in distinguishing opioid-exposed infants from controls. Our findings support the clinical phenotype of infants exposed to opioids in utero and may potentially explain the higher rates of visual and emotional problems observed in this population. Finally, our findings suggested that edge-centric networks could better capture the neural differences between opioid-exposed infants and controls by abstracting the intrinsic co-fluctuation along edges, which may provide a promising tool for future studies focusing on investigating the effects of prenatal opioid exposure on neurodevelopment.

Ophthalmic outcomes in children exposed to opioid maintenance treatment in utero: A systematic review and meta-analysis

Opioid use disorder is a significant global issue and the rate of opioid use in women of childbearing age and pregnant women is on the rise. Whilst the adverse general health, cognitive, and neurodevelopmental outcomes of in utero exposure to opioids have been explored, there is a lack of prospective, controlled, longitudinal research into the ophthalmic outcomes. Existing research suggests that there is an association between prenatal exposure and future risk of abnormalities in visual functioning. This systematic review and meta-analysis analysed studies that measured eye abnormalities in infants or children exposed to opioid maintenance therapy in utero and compared them to non-opioid exposed controls. After considering the clinical findings, limitations of the studies, confounding factors, and quantitative analysis, a causal relationship between in utero opioid exposure and future eye abnormalities could not be confirmed. The implications of the findings and their clinical relevance, in addition to identified gaps for future research are also discussed in this paper.

Sex-Dependent Synaptic Remodeling of the Somatosensory Cortex in Mice With Prenatal Methadone Exposure

Rising opioid use among pregnant women has led to a growing population of neonates exposed to opioids during the prenatal period, but how opioids affect the developing brain remains to be fully understood. Animal models of prenatal opioid exposure have discovered deficits in somatosensory behavioral development that persist into adolescence suggesting opioid exposure induces long lasting neuroadaptations on somatosensory circuitry such as the primary somatosensory cortex (S1). Using a mouse model of prenatal methadone exposure (PME) that displays delays in somatosensory milestone development, we performed an un-biased multi-omics analysis and investigated synaptic functioning in the primary somatosensory cortex (S1), where touch and pain sensory inputs are received in the brain, of early adolescent PME offspring. PME was associated with numerous changes in protein and phosphopeptide abundances that differed considerably between sexes in the S1. Although prominent sex effects were discovered in the multi-omics assessment, functional enrichment analyses revealed the protein and phosphopeptide differences were associated with synapse-related cellular components and synaptic signaling-related biological processes, regardless of sex. Immunohistochemical analysis identified diminished GABAergic synapses in both layer 2/3 and 4 of PME offspring. These immunohistochemical and proteomic alterations were associated with functional consequences as layer 2/3 pyramidal neurons revealed reduced amplitudes and a lengthened decay constant of inhibitory postsynaptic currents. Lastly, in addition to reduced cortical thickness of the S1, cell-type marker analysis revealed reduced microglia density in the upper layer of the S1 that was primarily driven by PME females. Taken together, our studies show the lasting changes on synaptic function and microglia in S1 cortex caused by PME in a sex-dependent manner.

Psychotropic drug abuse in pregnancy and its impact on child neurodevelopment: A review

Substance abuse by women of child-bearing age and fetal in utero drug exposure has increased in the number of infants born with health issues. Prenatal exposure to psychoactive substances can lead to neurological and neurodevelopmental deficits later in life. Useful data concerning the effects of psychoactive drugs on fetal neurodevelopmental status are sparse. Understanding the neurodevelopmental consequences of prenatally drug-exposed children has become a pressing global concern. The aim of this review is to gather current evidence and information on neurodevelopmental outcomes of in utero drug exposure. A literature search was performed on the PubMed, Scopus, and Google Scholar databases using the terms “psychotropic drugs”, “neurodevelopmental consequences”, “prenatal drug exposure”, and “pregnancy”. Available studies on in utero drug exposure were reviewed and found to support the idea that some degree of health issues are present in fetuses and children. Different psychoactive substances have profound neurodevelopmental consequences, such as structural brain changes, poor attention span, Down syndrome, attention deficit hyperactivity disorder, autism spectrum disorder, imbalances in neurotransmitter levels, and many structural deficits. The pervasive use of psychoactive drugs in women of child-bearing age is an important health concern. Further scientific efforts are needed to investigate the effect of prenatal exposure to psychoactive drugs on children.

Opioids and the developing brain: time to rethink perinatal care for infants of opioid-dependent mothers

Illicit use of opioids is a global health crisis with major implications for women and children. Strategies for managing opioid use disorder (OUD) in pregnancy have been tested over the past 40 years, but studies have focused on maternal and pregnancy outcomes, with less attention given to long-term follow-up of exposed children. Here, we provide a narrative review of recent advances in the assessment and management of neonatal opioid withdrawal syndrome (NOWS), and we summarise evidence from multiple domains-neuroimaging, electrophysiology, visual development and function, neurodevelopment, behaviour, cognition and education-which suggests that prenatal opioid exposure modifies child development. Further studies are required to determine the optimal management of pregnant women with OUD and babies with NOWS. We identify knowledge gaps and suggest that future study designs should evaluate childhood outcomes, including infant brain development and long-term neurocognitive and visual function.

Effects of exposure in utero to buprenorphine on oxidative stress and apoptosis in the hippocampus of rat pups

The study investigated the effect of buprenorphine (BUP) on oxidative indices and gene expression of apoptotic molecules in the hippocampus of neonates during the fetal stage. BUP (1 or 0.5 mg/kg) was subcutaneously administrated to pregnant rat dams. After parturition, the pups were maintained to the end of breastfeeding period, then hippocampi were assessed for oxidative stress indices [glutathione (GSH), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), total antioxidant capacity (TAC)] and mRNA expression of apoptotic markers (Bax, Bcl2 and caspase 3). Our data indicated that BUP (0.5 mg/kg) administration during gestation significantly increased GSH and TAC concentrations in the hippocampus of pups versus control group (p < 0.05). BUP (0.5 and 1 mg/kg) administration significantly elevated the expression levels of Bcl2 in the hippocampus of neonates compared with controls. BUP injection (0.5 and 1 mg/kg) to pregnant rats markedly reduced the expression levels of caspase 3 in the hippocampus of neonates in BUP 0.5 group (p < 0.01) and BUP 1 group (p < 0.05) versus the controls. Our study indicated that BUP may potentiate antioxidant system and inhibit apoptosis and oxidative stress in the hippocampus of neonates received this drug during the fetal stage.

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BUP at low doses may potentiate antioxidant system.

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BUP at low dose may inhibit oxidative stress.

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BUP at low dose may act as an anti-apoptotic agent.

Mental health and use of health care services in opioid-exposed school-aged children compared to foster children

Given the concerns raised regarding the effects of prenatal exposure to methadone and buprenorphine on the developmental outcomes of the children, this study assessed mental health and use of services in a national sample of school-aged children (N = 78) born to women enrolled in opioid maintenance treatment during pregnancy, compared with a group of foster children (N = 140). The majority of the opioid-exposed children lived with their birth parent(s) at the time of assessment (N = 62), while 16 lived in foster homes. Caregivers completed the Strengths and Difficulties Questionnaire (SDQ) and the Reactive Attachment Disorder scale. Teachers completed the SDQ. Three kinds of services were included in measuring service use: school-based education services, child mental health services, and hospital-based habilitation services. The main finding of the study is that children prenatally exposed to methadone or buprenorphine living with their family of origin had significantly better mental health status than their foster-placed counterparts and that of the comparison group of foster children. In addition, the exposed children living at home had less child welfare involvement, and only half of them were using any of the three services measured. The odds for using services increased significantly in accordance with increasing mental health problems, independent of group affiliation, indicating a need-based access to services. In line with other studies, we found that the odds for using one or more services was 2.3 times greater for boys than for girls. Our results contribute to a more-nuanced understanding of the developmental outcomes of prenatal exposure to methadone and buprenorphine, and factors associated with increased service use in groups of at-risk children.

Children born to women in opioid maintenance treatment: A longitudinal study of child behavioral problems and parenting stress

In the wake of the "opioid epidemic", there is considerable concern regarding potential harmful long-term effects of prenatal opioid exposure. Opioid misuse and addiction confer increased exposure to lifestyle stressors and health burdens. Accordingly, it is challenging to disentangle effects of prenatal opioid exposure per se from factors related to maternal stress. In this study, we followed 36 women enrolled in comprehensive opioid maintenance treatment (OMT) program and their children alongside 36 age-matched mother-child dyads from a community sample (COMP) from pregnancy until child-age 8 years. Across five sessions, we used a battery of well-established questionnaires to investigate trajectories of parenting stress and mental health symptoms as well as child behavior problems. The 8-year retention was relatively high (OMT: 72%, COMP: 67%), and the OMT sample remarkably stable and well-functioning, with minimal concomitant illicit drug use. Mixed effects regressions showed significantly different trajectories of child behavior problems (F = 3.8, p = 0.024) and parenting stress (F = 3.1, p = 0.016) in the two groups. Differences in experienced stress were largely explained by more distress specifically related to the parenting role in the OMT group (F = 9.7, p = 0.003). The OMT sample also reported higher psychological distress (F = 15.6, p < 0.001) than the comparison group, but notably few participants presented with problems that warranted clinical intervention. The results underscore the benefits of tailored follow-up of children prenatally exposed to opioids and their families beyond infancy and toddlerhood. Long-term direct effects of prenatal opioid exposure on behavior problems are likely modest, given an otherwise stable caregiving environment conducive to healthy development.

Substance Use in Pregnancy: Identifying Stigma and Improving Care

This review examines the impact of stigma on pregnant people who use substances. Stigma towards people who use drugs is pervasive and negatively impacts the care of substance-using people by characterizing addiction as a weakness and fostering beliefs that undermine the personal resources needed to access treatment and recover from addiction, including self-efficacy, help seeking and belief that they deserve care. Stigma acts on multiple levels by blaming people for having a problem and then making it difficult for them to get help, but in spite of this, most pregnant people who use substances reduce or stop using when they learn they are pregnant. Language, beliefs about gender roles, and attitudes regarding fitness for parenting are social factors that can express and perpetuate stigma while facilitating punitive rather than therapeutic approaches. Because of stigmatizing attitudes that a person who uses substances is unfit to parent, pregnant people who use substances are at heightened risk of being screened for substance use, referred to child welfare services, and having their parental rights taken away; these outcomes are even more likely for people of color. Various treatment options can successfully support recovery in substance-using pregnant populations, but treatment is underutilized in all populations including pregnant people, and more knowledge is needed on how to sustain engagement in treatment and recovery activities. To combat stigma when working with substance-using pregnant people throughout the peripartum period, caregivers should utilize a trauma-informed approach that incorporates harm reduction and motivational interviewing with a focus on building trust, enhancing self-efficacy, and strengthening the personal skills and resources needed to optimize health of the parent-baby dyad.

Developmental Stressors Induce Innate Immune Memory in Microglia and Contribute to Disease Risk

Many types of stressors have an impact on brain development, function, and disease susceptibility including immune stressors, psychosocial stressors, and exposure to drugs of abuse. We propose that these diverse developmental stressors may utilize a common mechanism that underlies impaired cognitive function and neurodevelopmental disorders such as schizophrenia, autism, and mood disorders that can develop in later life as a result of developmental stressors. While these stressors are directed at critical developmental windows, their impacts are long-lasting. Immune activation is a shared pathophysiology across several different developmental stressors and may thus be a targetable treatment to mitigate the later behavioral deficits. In this review, we explore different types of prenatal and perinatal stressors and their contribution to disease risk and underlying molecular mechanisms. We highlight the impact of developmental stressors on microglia biology because of their early infiltration into the brain, their critical role in brain development and function, and their long-lived status in the brain throughout life. Furthermore, we introduce innate immune memory as a potential underlying mechanism for developmental stressors' impact on disease. Finally, we highlight the molecular and epigenetic reprogramming that is known to underlie innate immune memory and explain how similar molecular mechanisms may be at work for cells to retain a long-term perturbation after exposure to developmental stressors.

Prenatal opioid administration induces shared alterations to the maternal and offspring gut microbiome: A preliminary analysis

Background While many studies have described the impact of prenatal opioid exposure on development, possible mechanisms for how opioids exert developmental impairments remain elusive. Emerging evidence indicates disruptions in the maternal gut microbiome can alter offspring development; however, no studies to date have examined the impact of maternal opioid treatment on maternal-offspring microbiome dysbiosis. Methods A mouse model of prenatal methadone exposure (PME) was employed to assess the impact of maternal opioid treatment on the microbiome of methadone-treated dams (MD) and their offspring. Fecal samples were collected from dams (n = 8 per treatment), one male and one female offspring per dam (n = 8 offspring per sex per treatment) for 16S rRNA sequencing. Results Methadone treatment significantly increased the microbial diversity and led to an expansion in family level bacterial abundance. Correlational analysis revealed significant positive associations between dam and offspring measures of diversity indicating methadone-induced shifts in the microbial communities are shared between dam and offspring. Sixteen features in dams and 10 features in offspring were significantly differentially abundant between treatment groups with many features corresponding to the Lachnospiraceae NK4A136 genus. Of the six features identified as differentially abundant in both MD and PME offspring, all were assigned to the Lachnospiraceae NK4A136 group, and the abundances demonstrated strong positive correlations between dam and offspring. Conclusions These preliminary findings indicate that maternal opioid treatment during pregnancy alters the composition of the maternal microbiome, and this opioid-induced shift is similarly observed in offspring which could contribute to the impaired developmental phenotypes previously described.

Prenatal methadone exposure and child developmental outcomes in 2-year-old children

AIM

To examine the developmental outcomes of children born to opioid-dependent females enrolled in methadone maintenance and identify pre- and postnatal factors that place these children at developmental risk.

METHOD

Ninety-nine methadone-maintained females and their 100 infants (42 females, 58 males, mean gestational age 38.8wks) were recruited during pregnancy/at birth and studied to age 2 years alongside a regionally representative comparison group of 108 non-methadone-maintained females and their 110 infants (62 females, 48 males, mean gestational age 39.2wks). Information about perinatal exposure was collected from medical records, maternal urine and infant meconium toxicological analysis, maternal interviews (at birth and at 18mo), and a home visit (at 18mo). At age 2 years, child neuromotor function, cognition, language, and emotional/behavioral dysregulation were assessed.

RESULTS

Opioid-exposed children achieved lower motor, cognitive, and language scores and had poorer self, emotional, eating/feeding, and sensory processing regulation than unexposed children. After adjustment for maternal education and other substance use in pregnancy, between-group differences in child motor, cognitive, and overall dysregulation remained. Postnatal parental and family factors explained a further 40% to 52% of between-group differences in child outcomes.

INTERPRETATION

These children and families are extremely high-risk and need antenatal and postnatal support. Children exposed to opioids during pregnancy have pervasive developmental difficulties by age 2 years. These challenges are largely explained by adverse pregnancy and socio-environmental exposures, emphasizing the importance of specialist prenatal care and postnatal intervention support. What this paper adds Children born to opioid-dependent females are at high risk of pervasive developmental problems. These problems span a range of functional domains, including motor, cognitive, language, and behavioral/emotional dysregulation. Contributing factors include other adverse pregnancy exposures, postnatal environmental factors, and the direct effects of prenatal opioid exposure.

Prenatal methadone exposure impairs adolescent cognition and GABAergic neurodevelopment in a novel rat model of maternal methadone treatment

Methadone maintenance treatment (MMT) is the most common treatment for opioid-dependent pregnant women worldwide. Despite its widespread use, MMT is associated with a variety of adverse neurodevelopmental outcomes in exposed offspring, particularly cognitive impairments. The neurobiological abnormalities underlying these cognitive impairments are, however, poorly understood. This is, in part, due to a lack of animal models that represents the standard of care that methadone is administered in the clinic, with inconsistencies in the timing, doses and durations of treatment. Here we describe the characterisation of a clinically relevant rat model of MMT in which the long-term behavioural and neurobiological effects of prenatal methadone exposure can be assessed in adolescent offspring. Female Sprague-Dawley rats were treated orally with an ascending methadone dosage schedule (5, 10, 15, 20, 25 and 30 mg/kg/day), self-administered in drinking water prior to conception, throughout gestation and lactation. Pregnancy success, maternal gestational weight gain, litter survival and size were not significantly altered in methadone-exposed animals. Methadone-exposed offspring body and brain weights were significantly lower at birth. Novel object recognition tests performed at adolescence revealed methadone-exposed offspring had impaired recognition memory. Furthermore, the rewarded T-maze alternation task demonstrated that methadone-exposed female, but not male, offspring also exhibit working memory and learning deficits. Immunoblots of the adolescent prefrontal cortex and hippocampus showed methadone-exposed offspring displayed reduced levels of mature BDNF, in addition to the GABAergic proteins, GAD67 and parvalbumin, in a sex- and brain region-specific fashion. This rat model closely emulates the clinical scenario in which methadone is administered to opioid-dependent pregnant woman and provides evidence MMT can cause cognitive impairments in adolescent offspring that may be underlined by perturbed neurodevelopment of the GABAergic system.

Effects of prenatal opioid exposure on functional networks in infancy

Prenatal opioid exposure has been linked to altered neurodevelopment and visual problems such as strabismus and nystagmus. The neural substrate underlying these alterations is unclear. Resting-state functional connectivity MRI (rsfMRI) is an advanced and well-established technique to evaluate brain networks. Few studies have examined the effects of prenatal opioid exposure on resting-state network connectivity in infancy. In this pilot study, we characterized network connectivity in opioid-exposed infants (n = 19) and controls (n = 20) between 4–8 weeks of age using both a whole-brain connectomic approach and a seed-based approach. Prenatal opioid exposure was associated with differences in distribution of betweenness centrality and connection length, with positive connections unique to each group significantly longer than common connections. The unique connections in the opioid-exposed group were more often inter-network connections while unique connections in controls and connections common to both groups were more often intra-network. The opioid-exposed group had smaller network volumes particularly in the primary visual network, but similar network strength as controls. Network topologies as determined by dice similarity index were different between groups, particularly in visual and executive control networks. These results may provide insight into the neural basis for the developmental and visual problems associated with prenatal opioid exposure.

Obstetrical, fetal, and lactation pharmacology-a crisis that can no longer be ignored

The data available to inform pregnant and lactating women about drug safety and efficacy are woefully inadequate. This lack of information encompasses every aspect of pharmaceutics, including limited human data about the embryonic risk, limited pharmacokinetic and pharmacodynamic information during and after pregnancy to ensure proper dosing, and a dearth of new medications to treat obstetrical and lactation disorders. This state of affairs has been longstanding and can be attributed to several realities, most of which have withstood any efforts to modify them. The first reality is the disinterest of the pharmaceutical industry to undertake pregnancy and lactation studies because of the considerable disincentives to undertake such studies. The medicolegal risks and the limited opportunity for financial gain are significant barriers to their participation. The US Food and Drug Administration has not mandated that new drugs or drugs "on patent" must include studies in pregnant women. Regulatory constrains that have defined pregnant women as a vulnerable class have greatly limited pharmacologic studies. Another contributing factor to this lack of information is the lack of researchers skilled in pharmacology with an interest in the pregnant woman. In addition, although difficult to measure, there is the hesitancy of pregnant and lactating women to participate in pharmacology research either for fear of fetal risk or an inability to commit the time required for such studies. Research in obstetrical and lactation pharmacology lags far behind that of pediatric pharmacology. Through the efforts of many, research in that field is highly funded and very productive in providing new information on medications used in children who, like pregnant women, have differing pharmacologic needs based on age (chronology for children and gestational age for pregnant women). Recently, the deficiencies and possible remedies for this embarrassing state of affairs in obstetrical and lactation pharmacology have been addressed by the federal government, which led to 15 recommendations from the Task Force on Research Specific to Pregnant Women and Lactating Women. In this article, we address the challenges in providing meaningful information about specific medications used by the mother and how these problems have evolved. We also suggest specific strategies to start the process of remediation.

Integrated Review of the Assessment of Newborns With Neonatal Abstinence Syndrome

OBJECTIVE

To critically review and summarize current knowledge regarding the assessment of newborns with neonatal abstinence syndrome (NAS).

DATA SOURCES

We searched the following databases for articles on the assessment of newborns with NAS that were published in English between January 2014 and June 2020: PubMed, CINAHL, and PsycINFO. Keywords and Medical Subject Heading terms used to identify relevant research articles included neonatal abstinence syndrome; Finnegan Scale; eat, sleep, console; epigenetics; genetics; pharmacokinetics; and measurement. We independently reviewed articles for inclusion.

STUDY SELECTION

We retrieved 435 articles through database searches and 17 through manual reference searches; 31 articles are included in the final review. Excluded articles were duplicates, not relevant to NAS, qualitative studies, and/or of low quality.

DATA EXTRACTION

We used the methodology of Whittemore and Knafl to guide this integrative review. We extracted and organized data under the following headings: author, year and country, purpose, study design, participants, measurement, biomarker (if applicable), results, limitations, recommendations, and intervention.

DATA SYNTHESIS

The Finnegan Neonatal Abstinence Scale is the most widely used instrument to measure symptoms of NAS in newborns, although it is very subjective. Recently, there has been a transition from the Finnegan Neonatal Abstinence Scale to the eat, sleep, console method, which consists of structured assessment and intervention and has been shown to decrease length of hospital stay and total opioid treatment dose. Researchers examined biomarkers of NAS, including genetic markers and autonomic nervous system responses, on the variation in incidence and differential severity of NAS. In the included articles, women with opioid use disorder who were treated with naltrexone during pregnancy gave birth to newborns without NAS diagnoses. However, most women who were treated with buprenorphine gave birth to newborns with NAS diagnoses.

CONCLUSION

NAS negatively affects newborns in a multitude of ways, and the objective assessment and measurement of the newborn's response to withdrawal remains understudied and needs further investigation.

Intrapartum opioid analgesia and childhood neurodevelopmental outcomes among infants born preterm

BACKGROUND

There are concerns regarding neurobehavioral changes in infants exposed to parenteral opioids during labor; however, long-term neurodevelopment remains unstudied.

OBJECTIVE

We aimed to examine the association between parenteral opioids used as labor analgesia and perinatal outcomes and childhood neurodevelopment until 2 years of age among infants born prematurely. We hypothesized that intrapartum exposure to parenteral opioids is associated with impaired neurodevelopment and adverse perinatal outcomes.

STUDY DESIGN

This was a secondary analysis of a multicenter, randomized controlled trial assessing magnesium for the prevention of cerebral palsy in infants at risk for preterm birth. Women delivering a singleton, nonanomalous, live infant before 37 weeks' gestation were considered for inclusion. Women were excluded if they had missing exposure or primary outcome data, were exposed to general anesthesia, or reported use of heroin or unspecified illicit drugs. Women reporting use of nonopioid illicit drugs such as cocaine and marijuana were not excluded. Groups were compared based on exposure or nonexposure to parenteral opioids (intravenous or intramuscular) used as labor analgesia. The primary outcome was any psychomotor or mental developmental delay at 24 months according to the Bayley Scales of Infant Development II. Secondary outcomes were the Bayley Scales of Infant Development II subdomains and adverse perinatal outcomes. Multivariable logistic regression models were performed and adjusted odds ratios with 95% confidence intervals were estimated.

RESULTS

Of the 1404 women included, 535 (38%) received parenteral opioids as labor analgesia. Women receiving parenteral opioids were more likely to be younger, Hispanic, and present with cervical dilation ≥4 cm. Parenteral opioid recipients had lower rates of illicit nonopioid drug or tobacco use, a lower rate of cesarean delivery, lower educational level and were less likely to be undergoing induction. Women receiving parenteral opioids who underwent cesarean delivery were less likely to do so because of a nonreassuring fetal status. In the unadjusted and adjusted analyses, there were no significant differences in the primary outcomes of psychomotor or mental developmental delay at 2 years of age (adjusted odds ratio, 0.96; confidence interval, 0.76-1.20). The only significant difference in secondary outcomes was a shorter O₂ requirement duration in the parenteral opioid group (2 vs 4 days; P=.002).

CONCLUSION

Among a population of preterm infants vulnerable to neurologic impairment, intrapartum exposure to parenteral opioids was not associated with an increased risk for neurodevelopmental delay up to 2 years of age, nor did these infants have worse perinatal outcomes.

Preschool Language Development of Children Born to Women with an Opioid Use Disorder

Increasing evidence suggests that prenatal exposure to opioids may affect brain development, but limited data exist on the effects of opioid-exposure on preschool language development. Our study aimed to characterize the nature and prevalence of language problems in children prenatally exposed to opioids, and the factors that support or hinder language acquisition. A sample of 100 children born to pregnant women in methadone maintenance treatment and 110 randomly identified non-exposed children were studied from birth to age 4.5 years. At 4.5 years, 89 opioid-exposed and 103 non-exposed children completed the preschool version of the Clinical Evaluation of Language Fundamentals (CELF-P) as part of a comprehensive neurodevelopmental assessment. Children prenatally exposed to opioids had poorer receptive and expressive language outcomes at age 4.5 years compared to non-opioid exposed children. After adjustment for child sex, maternal education, other pregnancy substance use, maternal pregnancy nutrition and prenatal depression, opioid exposure remained a significant independent predictor of children’s total CELF-P language score. Examination of a range of potential intervening factors showed that a composite measure of the quality of parenting and home environment at age 18 months and early childhood education participation at 4.5 years were important positive mediators.

Neonatal opioid exposure: public health crisis and novel neuroinflammatory disease

Substance use, specifically the use of prescription and non-prescription opioids among pregnant women, is a major public health issue and chief contributor to the opioid crisis. The prevalence of Neonatal Opioid Withdrawal Syndrome has risen 5-fold in the past decade, and is a well-recognized consequence of perinatal opioid exposure. By contrast, the long-term damage to the developing brain from opioid medications is just beginning to be recognized as a serious concern. Published data suggest that opioid exposure commencing in utero negatively affects the maturation of the neural-immune system, and trajectory of central nervous system development. Methadone induces peripheral immune hyper-reactivity, lasting structural and microstructural brain injury, and significant deficits in executive function and cognitive control in adult animals following in utero exposure. Thus, to address the cascading public health crisis stemming from the multitude of infants with in utero opioid exposure who will grow up with altered neurodevelopmental trajectories, rigorous preclinical, mechanistic studies are required. Such studies will define the long-term sequelae of prenatal opioid exposure in an effort to develop appropriate and targeted interventions. Specifically, the development of novel fluid, neuroimaging and biobehavioral biomarkers will be the most useful to aid in early identification and treatment of opioid exposed infants with the greatest risk of poor clinical outcomes. These studies will be essential to understand how in utero insults determine brain structure and function in adulthood, and what targeted interventions will be required to improve long-term outcomes in the countless children being born exposed to opioids each year.

Prenatal Opioid Exposure and ADHD Childhood Symptoms: A Meta-Analysis

To systematically investigate the association between prenatal opioid exposure (POE) and attention-deficit hyperactivity disorder (ADHD) symptoms in children 2-18 years old, studies were searched using PubMed, CINAHL, PsycINFO, and Web of Science from January of 1950 to October of 2019. Inclusion criteria were observational studies reporting ADHD symptoms of children with POE compared with non-exposed children or normative data. The study protocol was registered with PROSPERO: CRD42018115967. Two independent reviewers extracted data on hyperactivity/impulsivity, inattention symptoms, ADHD combined subscale symptoms, and sample characteristics. Of 223 articles screened, seven met the inclusion criteria. Data represent 319 children with POE and 1308 non-exposed children from 4.3 to 11.2 mean years from five countries. POE was positively associated with childhood hyperactivity/impulsivity (d = 1.40; 95% CI, 0.49-2.31; p = 0.003), inattention (d = 1.35; 95% CI, 0.69-2.01; p < 0.0001), and combined ADHD symptoms scores (d = 1.27; 95% CI = 0.79-1.75; p < 0.0001). POE was positively associated with ADHD combined symptom scores at preschool (d = 0.83, 95% CI, 0.57, 1.09; p < 0.0001) and school age (d = 1.45, 95% CI, 0.85 to 2.04; p < 0.0001). Results suggest increased risk of ADHD symptoms during school age. Future research is needed to clarify the relationship between biological, social, and environmental risk and ADHD symptoms for children who experienced POE.

Childhood Health and Educational Outcomes After Neonatal Abstinence Syndrome: A Systematic Review and Meta-analysis

OBJECTIVE

To systematically review and meta-analyze the association between neonatal abstinence syndrome (NAS) and adverse health or educational childhood outcomes.

STUDY DESIGN

An all-language search was conducted across 11 databases between January 1, 1975, and September 3, 2019; 5865 titles were identified. Observational studies of children between 28 days and 16 years of age, in whom a diagnosis of NAS was documented, were included. Outcomes included reasons for hospital admissions, childhood diagnoses, developmental outcomes, and academic attainment scores. All studies underwent independent review by 2 trained reviewers, who extracted study data and assessed risk of bias using the Newcastle Ottawa Tool.

RESULTS

Fifteen studies were identified that included 10 907 children with previous NAS and 1 730 213 children without previous NAS, aged 0-16 years. There was a strong association between NAS and subsequent child maltreatment (aOR, 6.49; 95% CI, 4.46-9.45; I² = 52%), injuries and poisoning (aOR, 1.34; 95% CI, 1.21-1.49; I² = 0%), and a variety of mental health conditions. Studies consistently demonstrated an increased incidence of strabismus and nystagmus among those with previous NAS. Children with NAS also had lower mean academic scores than the control group in every domain of testing across age groups.

CONCLUSIONS

NAS is significantly associated with future child maltreatment, mental health diagnoses, visual problems, and poor school performance. Owing to the necessary inclusion of nonrandomized studies, incomplete reporting among studies, and likely unadjusted confounding, this review does not suggest causation. However, we highlight associations requiring further investigation and targeted intervention, to positively impact the life course trajectories of this growing population of children.

Prenatal opioid exposure - Increasing evidence of harm

Prenatal opioid exposure adversely impacts upon fetal growth and places the newborn at risk of neonatal opioid withdrawal. The severity and duration of opioid withdrawal cannot be predicted in the individual baby and may be contributed to by other drugs including benzodiazepines and alcohol as well as cigarette smoking. Mitigating factors include breastfeeding, rooming in and absence of maternal polypharmacy. Less well recognised are a variety of other complications associated with prenatal opioid exposure including epigenetic changes, effects on neurophysiological function and structural alterations to the developing brain. The visual system is significantly affected, with changes to both clinical and electrophysiological function persisting at least to mid-childhood. Longer term neurodevelopmental and behavioural outcomes are confounded by multiple factors including poverty, parent-child interaction and small study numbers, but systematic reviews consistently demonstrate poorer outcomes for those children and young people prenatally exposed to opioids. Crucially, manifestation of neonatal withdrawal is not a prerequisite for important long term problems including behavioural, emotional or motor function disorder, sensory or speech disorder, strabismus and nystagmus. A body of evidence supports an independent adverse effect of prenatal opioid exposure upon fetal brain development, mediated via a systemic neuro-inflammatory process. Children prenatally exposed to opioids should remain under appropriate follow up, at least until school entry, as difficulties may only become apparent in mid-childhood. Future studies of the management of opioid use disorder in pregnancy, including maintenance methadone, must include longer term outcomes for the baby.

Prenatal exposure to methadone or buprenorphine alters µ-opioid receptor binding and downstream signaling in the rat brain

There is a growing concern related to the use of opioid maintenance treatment during pregnancy. Studies in both humans and animals have reported reduced cognitive functioning in offspring prenatally exposed to methadone or buprenorphine; however, little is known about the neurobiological mechanisms underlying these impairments. To reveal possible neurobiological effects of such in utero exposure, we examined brain tissue from methadone- and buprenorphine-exposed rat offspring previously shown to display impaired learning and memory. We studied µ-opioid receptor (MOR) and N-methyl-D-aspartate receptor (NMDAR) binding in the rat offspring cerebrum during development and in the hippocampus at young adulthood. Moreover, we examined activation of the Ca2+ /calmodulin-dependent protein kinase II (CaMKII) and the extracellular signal-regulated kinase (ERK), which are central in the downstream signaling of these receptors. The methadone- and buprenorphine-exposed rat pups displayed reduced MOR binding up to two weeks after birth, whereas the NMDAR binding was unaffected. Prenatal exposure to methadone or buprenorphine also resulted in decreased activation of CaMKII and/or ERK during development, while young adult offspring displayed increased hippocampal ERK activation. In conclusion, our findings suggest that prenatal exposure to exogenous opioids, such as methadone or buprenorphine, may disturb the endogenous opioid system during development, with long-term effects on proteins important for cognitive functioning.

Prenatal exposure to methadone or buprenorphine impairs cognitive performance in young adult rats

BACKGROUND

Concerns have been raised about the use of opioid maintenance treatment (OMT) during pregnancy and negative effects for the offspring. While neonatal outcomes and short-term effects are relatively well described, studies examining long-term effects in adolescents and adults are absent. The aim of the present study was to examine effects on learning and memory in young adult rats prenatally exposed to methadone or buprenorphine.

METHODS

Female rats were implanted with a 28-day osmotic minipump delivering methadone (10 mg/kg/day), buprenorphine (1 mg/kg/day) or vehicle 5 days prior to mating. To examine possible effects on cognitive functioning, young adult offspring were included in three different behavioral tests that examine recognition memory, nonspatial, and spatial learning and memory. In addition, offspring growth and maternal behavior after birh were investigated.

RESULTS

Prenatal exposure to methadone or buprenorphine caused impaired recognition memory and nonspatial reference learning and memory in young adult rats compared with the vehicle-treated group. Methadone-exposed offspring, but not the buprenorphine-exposed, also showed reduced long-term spatial memory. We did not observe any changes in maternal behavior or offspring growth after prenatal exposure to methadone or buprenorphine, suggesting that the impaired cognitive functioning is due to the opioid exposure rather than reduced maternal caregiving.

CONCLUSION

The present findings of long-term cognitive impairments in methadone- and buprenorphine-exposed offspring points to a negative impact of OMT on neurobiological development.

Subclinical and Overt Newborn Opioid Exposure: Prevalence and First-Year Healthcare Utilization

OBJECTIVES

To categorize newborn infants in Hamilton County, Ohio by late pregnancy fetal opioid exposure status and to assess their first-year healthcare utilization.

STUDY DESIGN

We used a population-based cohort of 41 136 live births from 2014-2017 and analyzed healthcare encounters in the first year of life from electronic health records. We prospectively assessed for the presence of opioids in maternal urine collected at delivery and for a diagnosis of newborn neonatal abstinence syndrome (NAS). At birth, infants were classified as unexposed to opioids, exposed to opioids and diagnosed with NAS, or subclinically exposed to opioids (exposure that did not result in NAS).

RESULTS

The prevalence of newborn opioid exposure was 37 per 1000 births. The duration of the hospital birth encounter was significantly longer for infants with subclinical exposure compared with unexposed infants (10% increase; 95% CI, 7%-13%). However, duration for infants with subclinical exposure was shorter compared to those with NAS. Neither subclinical exposure nor NAS was associated with total emergency department visits. Subclinical exposure was associated with increased odds of having at least 1 hospitalization in the first year. However, the total length of stay for hospitalizations was 82% that of the unexposed group (95% CI, 75%-89%). Infants with NAS had a 213% longer total length of stay compared with the unexposed group (95% CI, 191%-237%).

CONCLUSIONS

Subclinical and overt opioid exposure among newborn infants was associated with increased first-year healthcare utilization. From 2014 to 2017, this cost the Hamilton County healthcare system an estimated $1 109 452 for longer birth encounters alone.

Maternal Substance Use: Consequences, Identification, and Interventions

Alcohol, tobacco, and cannabis are the substances most frequently used during pregnancy, and opioid-exposed pregnancies have increased fourfold. The purpose of this review is to describe the prevalence and consequences of prenatal exposure to alcohol, tobacco, cannabis, and opioids. Currently available screening questionnaires for prenatal substance use are summarized and contrasted with the measures available for prenatal alcohol use. Because screening for prenatal alcohol and substance use is but the prelude to efforts to mitigate the potential adverse consequences, attempts for the modification of these consequences are briefly reviewed. In addition, areas of future research related to the criminalization of prenatal substance use, which may inhibit both inquiry and disclosure, are discussed. Indeed, the full potential of effective interventions has yet to be realized.

Perinatal Opioid Exposure Primes the Peripheral Immune System Toward Hyperreactivity

The increased incidence of opioid use during pregnancy warrants investigation to reveal the impact of opioid exposure on the developing fetus. Exposure during critical periods of development could have enduring consequences for affected individuals. Particularly, evidence is mounting that developmental injury can result in immune priming, whereby subsequent immune activation elicits an exaggerated immune response. This maladaptive hypersensitivity to immune challenge perpetuates dysregulated inflammatory signaling and poor health outcomes. Utilizing an established preclinical rat model of perinatal methadone exposure, we sought to investigate the consequences of developmental opioid exposure on in vitro activation of peripheral blood mononuclear cells (PBMCs). We hypothesize that PBMCs from methadone-exposed rats would exhibit abnormal chemokine and cytokine expression at baseline, with exaggerated chemokine and cytokine production following immune stimulation compared to saline-exposed controls. On postnatal day (P) 7, pup PMBCs were isolated and cultured, pooling three pups per n. Following 3 and 24 h, the supernatant from cultured PMBCs was collected and assessed for inflammatory cytokine and chemokine expression at baseline or lipopolysaccharide (LPS) stimulation using multiplex electrochemiluminescence. Following 3 and 24 h, baseline production of proinflammatory chemokine and cytokine levels were significantly increased in methadone PBMCs (p < 0.0001). Stimulation with LPS for 3 h resulted in increased tumor necrosis factor (TNF-α) and C-X-C motif chemokine ligand 1 (CXCL1) expression by 3.5-fold in PBMCs from methadone-exposed PBMCs compared to PBMCs from saline-exposed controls (p < 0.0001). Peripheral blood mononuclear cell hyperreactivity was still apparent at 24 h of LPS stimulation, evidenced by significantly increased TNF-α, CXCL1, interleukin 6 (IL-6), and IL-10 production by methadone PMBCs compared to saline control PBMCs (p < 0.0001). Together, we provide evidence of increased production of proinflammatory molecules from methadone PBMCs at baseline, in addition to sustained hyperreactivity relative to saline-exposed controls. Exaggerated peripheral immune responses exacerbate inflammatory signaling, with subsequent consequences on many organ systems throughout the body, such as the developing nervous system. Enhanced understanding of these inflammatory mechanisms will allow for appropriate therapeutic development for infants who were exposed to opioids during development. Furthermore, these data highlight the utility of this in vitro PBMC assay technique for future biomarker development to guide specific treatment for patients exposed to opioids during gestation.

Neurodevelopmental Outcomes of Children Born to Opioid-Dependent Mothers: A Systematic Review and Meta-Analysis

BACKGROUND

Children born to opioid-dependent mothers are at risk of adverse neurodevelopment. The magnitude of this risk remains inconclusive.

OBJECTIVE

To conduct a meta-analysis of studies that assessed neurodevelopmental outcomes of children aged 0 to 12 years born to opioid-dependent mothers, compared with children born to nonopioid-dependent mothers, across general cognitive, language, motor, and social-emotional domains.

DATA SOURCES

PubMed, CINAHL, PsycINFO, and Google Scholar databases.

STUDY ELIGIBILITY CRITERIA

English-language publications between January 1993 and November 2018, including prenatally opioid-exposed and nonopioid-exposed comparison children, reporting outcomes data on standardized assessments.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers independently extracted data. Pooled standardized mean differences (SMDs) were analyzed using random effects models. Risk of bias was assessed with the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Across 16 studies, individual domain outcomes data were examined for between 93 to 430 opioid-exposed and 75 to 505 nonopioid-exposed infants/children. Opioid-exposed infants and children performed more poorly than their nonopioid-exposed peers across all outcomes examined, demonstrated by lower infant cognitive (SMD = 0.77) and psychomotor scores (SMD = 0.52), lower general cognition/IQ (SMD = 0.76) and language scores (SMD = 0.65-0.74), and higher parent-rated internalizing (SMD = 0.42), externalizing (SMD = 0.66), and attention problems (SMD = 0.72).

LIMITATIONS

Most studies examined early neurodevelopment; only 3 reported school-age outcomes thereby limiting the ability to assess longer-term impacts of prenatal opioid exposures.

CONCLUSIONS AND IMPLICATIONS OF FINDINGS

Children born to opioid-dependent mothers are at modest- to high-risk of adverse neurodevelopment at least to middle childhood. Future studies should identify specific clinical and social factors underlying these challenges to improve outcomes.

Prenatal exposure to methadone or buprenorphine and long-term outcomes: A meta-analysis

AIM

To combine meta-analyses of multiple long-term outcomes in children prenatally exposed to methadone or buprenorphine through their mothers' Opioid maintenance therapy (OMT) with a systematic review of similar outcomes in experimental animals.

METHOD

The Medline, Embase, Web of Science, CINAHL, Cochrane and Epistemonikos databases were searched through August 30, 2018. Clinical studies measuring effects on cognitive, behavioral or visual outcomes in 3 months or older children prenatally exposed to OMT and control group(s) were included for meta-analyses. Experimental animal studies with similar exposures and outcomes were included in a systematic review. The three authors independently performed abstract screenings and full-text reviews, and extracted the data. One author performed the meta-analyses.

RESULTS

The pooled results of the meta-analyses showed worse cognitive, psychomotor, behavioral, attentional and executive functioning, and affected vision in children born to mothers who were in OMT during pregnancy compared to children without prenatal drug exposure (overall effect size = 0.49, 95% confidence interval = 0.38, 0.59, p < 0.00001). Many of the experimental animal studies showed impaired outcomes after prenatal exposure to methadone or buprenorphine. The clinical results may be biased, e.g., with the OMT group having more concurrent risk factors than the unexposed comparison group. There are few studies of older children.

CONCLUSION

Children born to mothers in OMT show worse outcomes for a number of different behaviors and impaired vision compared to children born to nonusers. Experimental animal studies indicate that there might be a causal relationship between prenatal methadone or buprenorphine exposure and subsequent negative outcomes.