The immediate and long-term effects of prenatal opioid exposure

Maternal exposure to buprenorphine, but not methadone, during pregnancy reduces social play behavior across two generations of offspring

RATIONALE

The prevalence of newborns exposed to medications for opioid use disorder (MOUD), such as methadone or buprenorphine, during pregnancy is increasing. The opioid system plays a crucial role in regulating and shaping social behavior, and children prenatally exposed to opioids face an increased risk of developing behavioral problems. However, the impact of prenatal exposure to MOUD on offspring's social behavior during adolescence and adulthood, as well as potential intergenerational effects, remains largely unexplored.

OBJECTIVES

Our study employed a translationally relevant animal model to investigate how maternal (F0) exposure to MOUD during pregnancy affects social behavior in young and adult rats across the first (F1) and second (F2) generation of offspring.

METHODS

Female Sprague-Dawley rats were implanted with an osmotic minipump delivering methadone (10 mg/kg/day), buprenorphine (1 mg/kg/day), or sterile water, prior to mating with drug-naïve males. Adult F1 females were mated with treatment-matched F1 males to generate F2 offspring. We assessed social play behavior in juvenile offspring, and social interaction behavior in a three-chamber social interaction test in young adults of the F1 and F2 generations.

RESULTS

Maternal exposure to buprenorphine, but not methadone, during pregnancy reduced social play behavior in both F1 and F2 offspring, expressed by a reduced number of pounces and pins, which are the two most characteristic parameters of social play in rats. Adult social interactions were unaffected by prenatal MOUD exposure across both generations.

CONCLUSIONS

Maternal exposure to buprenorphine during pregnancy may have adverse effects on social play behavior across two generations of offspring.

Health outcomes in children with prenatal opioid exposure with and without neonatal abstinence syndrome in the first seven years of life: An observational cohort study

INTRODUCTION

Prenatal opioid exposure (POE) is a major public health consequence of the opioid epidemic. Long-term health outcomes associated with POE remain unclear, especially for children with POE without a diagnosis of neonatal abstinence syndrome (NAS). Here, we aimed to describe the health outcomes of children with POE and with POE and NAS compared to unexposed children during the first 7 years of life.

DESIGN

In this retrospective observational cohort study, children born between 2015 and 2022 were identified from the Maternal and Infant Data Hub (MIDH), a data repository that continuously integrates maternal, neonatal, and pediatric records from two academic medical centers and one pediatric hospital system in the Midwest, USA.

METHODS

International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10 CM) chapters A00-N99 served as outcomes of interest. Annual incidence and crude incidence rate ratios were calculated to explore descriptive differences between the exposed and unexposed groups.

RESULTS

The study included 22,002 children, 20,130 (91.5%) of whom were unexposed and 1872 (8.5%) were exposed. Of the 1872 exposed children, 371 (19.8%) received a diagnosis of NAS (POE + NAS) and 1501 were in the POE-NAS group. Across all 7 years, exposed children had a higher incidence of diagnoses in most ICD-10 CM chapters compared to unexposed children. A consistently higher incidence rate ratio of diagnosis was observed in both POE-NAS and POE + NAS groups (vs. unexposed) related to mental and behavioral disorders, eye diagnoses, and diseases of the musculoskeletal system and gastrointestinal systems.

CONCLUSIONS

POE is associated with an increased risk of diagnoses in a number of ICD-10 CM chapters throughout childhood. These findings underscore the need for early screening and targeted interventions to support exposed children and improve their well-being. Further research is required to explore underlying mechanisms and develop preventive measures for at-risk populations.

CLINICAL RELEVANCE

Understanding the conditions more often diagnosed in children with prenatal opioid exposure will help to improve care provided to this population. As a result of study findings, nurses who provide care to children with prenatal opioid exposure can prioritize their assessments and allocate time, resources, and education toward areas more likely to be affected.

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.

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.

A Prospective Multi-Institutional Study Comparing the Brain Development in the Third Trimester between Opioid-Exposed and Nonexposed Fetuses Using Advanced Fetal MR Imaging Techniques

BACKGROUND AND PURPOSE

While the adverse neurodevelopmental effects of prenatal opioid exposure on infants and children in the United States are well described, the underlying causative mechanisms have yet to be fully understood. This study aims to compare quantitative volumetric and surface-based features of the fetal brain between opioid-exposed fetuses and unexposed controls by using advanced MR imaging processing techniques.

MATERIALS AND METHODS

This is a multi-institutional IRB-approved study in which pregnant women with and without opioid use during the current pregnancy were prospectively recruited to undergo fetal MR imaging. A total of 14 opioid-exposed (31.4 ± 2.3 weeks of gestation) and 15 unexposed (31.4 ± 2.4 weeks) fetuses were included. Whole brain volume, cortical plate volume, surface area, sulcal depth, mean curvature, and gyrification index were computed as quantitative features by using our fetal brain MR imaging processing pipeline.

RESULTS

After correcting for gestational age, fetal sex, maternal education, polysubstance use, high blood pressure, and MR imaging acquisition site, all of the global morphologic features were significantly lower in the opioid-exposed fetuses compared with the unexposed fetuses, including brain volume, cortical volume, cortical surface area, sulcal depth, cortical mean curvature, and gyrification index. In regional analysis, the opioid-exposed fetuses showed significantly decreased surface area and sulcal depth in the bilateral Sylvian fissures, central sulci, parieto-occipital fissures, temporal cortices, and frontal cortices.

CONCLUSIONS

In this small cohort, prenatal opioid exposure was associated with altered fetal brain development in the third trimester. This adds to the growing body of literature demonstrating that prenatal opioid exposure affects the developing brain.

Prenatal Opioid Exposure and Immune-Related Conditions in Children

Importance

Prenatal opioid exposure (POE) may alter with fetal development of the immune system, which may influence long-term health and susceptibility to immune-related conditions.

Objective

To compare the risk of hospitalization and emergency department presentation for immune-related conditions in children with and without POE.

Design, Setting, and Participants

This retrospective, population-based cohort study used linked administrative health records of all children born in Western Australia between January 1, 2003, and December 31, 2018 (N = 401 462).

Exposure

Prenatal exposure to prescription opioids (overall and by trimester), neonatal abstinence syndrome diagnosis, and opioid indication (pain or opioid use disorder [OUD]).

Main Outcomes and Measures

The main outcome was hospital admissions and emergency department presentations during which a child was diagnosed with an immune-related condition, including infections, conditions associated with an overactive immune system (eg, asthma, eczema, and allergy and anaphylaxis), and autoimmune diseases diagnosed before age 5 years or June 30, 2020. Data were analyzed between August 30, 2022, and February 27, 2023.

Results

Neonates with POE (1656 [0.4%]; mean [SD] gestational age, 37.7 [2.1] weeks; 836 females [50.5%]; 820 males [49.5%]) were more likely to be born preterm, have low birth weight for gestational age, and be coexposed to cigarette smoke compared with nonexposed neonates. Perinatal opioid exposure was associated with an increased risk of perinatal infection (adjusted odds ratio [AOR], 1.62; 95% CI, 1.38-1.90) and eczema and dermatitis (AOR, 11.91; 95% CI, 9.84-14.41) compared with nonexposure. Neonatal abstinence syndrome was also associated with both conditions (AOR, 2.91 [95% CI, 2.36-3.57] and 31.11 [95% CI, 24.64-39.28], respectively). Prenatal opioid exposure was also associated with an increased risk of childhood asthma (adjusted hazard ratio [AHR], 1.44; 95% CI, 1.16-1.79), but not allergies and anaphylaxis. It was also associated with an increased risk of childhood eczema and dermatitis, but only in children with POE from opioids used to treat OUD (AHR, 1.47; 95% CI, 1.08-1.99) rather than pain. In contrast, POE from opioids used for pain was associated with an increased risk of infection (AHR, 1.44; 95% CI, 1.32-1.58), but POE to opioids used to treat OUD was not. Autoimmune conditions were rare and were not observed to be associated with POE.

Conclusions and Relevance

In this cohort study, POE was associated with an increased risk of infection, eczema and dermatitis, and asthma, but not allergies and anaphylaxis or autoimmune conditions. These findings highlight the importance of further study of opioid-induced immune changes during pregnancy, the potential impact on long-term health in exposed children, and the mechanisms of opioid-induced immune dysregulation.

Neonatal Abstinence Syndrome: An Insight Over Impact of Maternal Substance Use

Neonatal abstinence syndrome (NAS) highlights the intricate interplay between maternal substance use during pregnancy and the challenges neonates face from the distressing global opioid crisis. This comprehensive review captures the multilayered landscape of NAS, encircling its underlying mechanisms, epidemiology, diagnostic intricacies, clinical manifestations, continuing developmental impacts, treatment paradigms, and the crucial role of multidisciplinary care. The core pathophysiology of NAS involves the transplacental passage of addictive substances, activating chemical dependence in the maturing fetus, which is characterized by neurotransmitter dysregulation, neuroadaptations, and receptor sensitization. A diverse clinical presentation ranges from central nervous system hyperactivity and autonomic dysregulation to gastrointestinal manifestations, necessitating homogenous assessment tools such as the Finnegan Neonatal Abstinence Scoring System. The demand for a multilayered approach is essential for comprehensive management, involving pharmacological interventions like morphine or methadone and non-pharmacological strategies such as swaddling. The complications of NAS are not only limited to but are also well beyond infancy, leading to behavioral, longstanding cognitive, and socioemotional consequences. Addressing these developmental arcs demands decisive longitudinal monitoring and early interventions. NAS management is fundamentally multidisciplinary, requiring the teamwork of nurses, social workers, psychologists, pediatricians, and neonatologists. Apart from the clinical realm, managing the psychosocial needs of families traversing NAS requires resources and empathy. A crucial comprehensive approach is essential to confront the challenges and limitations of NAS. From early identification and prevention to longstanding support through pharmacological, non-pharmacological, and psychological channels, it creates a holistic structure that emerges as the basis for understanding the complicated relationship between maternal substance use and its impact on neonates. An amalgamation of community engagement, society, policy initiatives, and medical expertise is essential to mitigate the repercussions of NAS and adopt healthier outcomes for affected infants.

A mini review of what matters in the management of NAS, is ESC the best care?

As the use of opioids and polysubstance by pregnant women has increased over the years, there has also been a sharp increase in cases of neonatal abstinence syndrome (NAS). Classically, infants affected by NAS have been cared for in neonatal intensive care units resulting in an increase of healthcare expenditure and resource utilization as well as separation from the families. Consequently, the Eat, Sleep, and Console (ESC) tool was developed and promoted as a novel method that focuses on maternal/infant dyad during hospital stay while decreasing the use of pharmacological interventions and therefore decreasing the length of stay and healthcare expenditure. Thus, it has been implemented in several hospitals in the United States. Although the training of staff has been proposed and the interventions of sleep, eat, and console are defined, there still exists a lack of standardization of this practice specifically in regard to the type of associated non-pharmacological practices as well as the reports of its short- and long-term outcomes.

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.