Neonatal Opioid Withdrawal Syndrome: An Update on Developmental Outcomes

Neurobehavioral Profiles in Opioid-Exposed and Unexposed Neonates

OBJECTIVE

To describe distinctive profiles of neurobehavior in opioid-exposed and unexposed neonates.

STUDY DESIGN

The Outcomes of Babies with Opioid Exposure study is a multisite, prospective, observational study in neonates born at term with opioid exposure and unexposed controls. As part of the Outcomes of Babies with Opioid Exposure study protocol, certified examiners administered the NeoNatal Neurobehavioral Scales, second edition (NNNS-II) before 6 weeks postnatal age. We used latent profile analysis to determine distinctive classes of neurobehavior and linear mixed effect models to compare NNNS-II scores by exposure status.

RESULTS

The study included 291 neonates with NNNS-II, 194 exposed and 97 unexposed. Latent profile analysis resulted in 4 unique classes. Class 4 showed the most signs of stress and included almost exclusively exposed neonates. Scores for exposed neonates were significantly different than unexposed neonates on most NNNS-II subscales. In addition to opioids, associations were found between profile membership and prenatal exposure to benzodiazepines, e-cigarettes/tobacco, and selective serotonin reuptake inhibitors.

CONCLUSIONS

Neonates with prenatal exposure to opioids and other psychotropic substances have distinctive patterns of neurobehavior. Additional follow-up is needed to determine if these neurobehavioral differences serve as a marker for future problems with attention and behavior.

CLINICAL TRIALS

GOV REGISTRATION

NCT04149509.

A human iPSC-derived midbrain neural stem cell model of prenatal opioid exposure and withdrawal: A proof of concept study

A growing body of clinical literature has described neurodevelopmental delays in infants with chronic prenatal opioid exposure and withdrawal. Despite this, the mechanism of how opioids impact the developing brain remains unknown. Here, we developed an in vitro model of prenatal morphine exposure and withdrawal using healthy human induced pluripotent stem cell (iPSC)-derived midbrain neural progenitors in monolayer. To optimize our model, we identified that a longer neural induction and regional patterning period increases expression of canonical opioid receptors mu and kappa in midbrain neural progenitors compared to a shorter protocol (OPRM1, two-tailed t-test, p =  0.004; OPRK1, p =  0.0003). Next, we showed that the midbrain neural progenitors derived from a longer iPSC neural induction also have scant toll-like receptor 4 (TLR4) expression, a key player in neonatal opioid withdrawal syndrome pathophysiology. During morphine withdrawal, differentiating neural progenitors experience cyclic adenosine monophosphate overshoot compared to cell exposed to vehicle (p =  0.0496) and morphine exposure conditions (p, =  0.0136, 1-way ANOVA). Finally, we showed that morphine exposure and withdrawal alters proportions of differentiated progenitor cell fates (2-way ANOVA, F =  16.05, p <  0.0001). Chronic morphine exposure increased proportions of nestin positive progenitors (p =  0.0094), and decreased proportions of neuronal nuclear antigen positive neurons (NEUN) (p =  0.0047) compared to those exposed to vehicle. Morphine withdrawal decreased proportions of glial fibrillary acidic protein positive cells of astrocytic lineage (p =  0.044), and increased proportions of NEUN-positive neurons (p <  0.0001) compared to those exposed to morphine only. Applications of this paradigm include mechanistic studies underscoring neural progenitor cell fate commitments in early neurodevelopment during morphine exposure and withdrawal.

Early childhood growth following prenatal opioid exposure and Neonatal Opioid Withdrawal Syndrome

BACKGROUND

Newborns with Neonatal Opioid Withdrawal Syndrome (NOWS) are at risk for smaller size at birth, including weight, length, and head circumference. We hypothesized that children with a history of prenatal opioid exposure and NOWS would have smaller size as infants and toddlers.

METHODS

This retrospective cohort study analyzed a cohort developed from the electronic medical records of all patients who were seen in the NOWS Clinic at a free-standing children's hospital system through age two years. Anthropometric measurements, demographics, substance and pharmacologic exposures, custodian status and nutritional data were extracted.

RESULTS

The final sample size included 1190 subjects with 7700 patient encounters. 1153 (97%) had four or more visits in the first two years of life. Forty-four percent of height measurements were below the tenth percentile. Prenatal methadone exposure was negatively associated with later growth. Infants with lower weight, height, and head circumference were prescribed higher caloric density infant formula. Forty percent of the weight measurements were less than the tenth percentile before 6 months, and this improved to 9.3% at 18-25-month visits.

CONCLUSION

Children with a history of prenatal opioid exposure are at risk for later short stature. Prenatal methadone exposure specifically is associated with decreased height.

IMPACT

This large retrospective cohort study found that toddlers with a history of prenatal opioid exposure and Neonatal Opioid Withdrawal Syndrome are at risk for short stature. Prenatal methadone, but not buprenorphine, exposure is negatively associated with later growth in children with a history of prenatal opioid exposure. The proportion of weight under the tenth percentile improved from infant to toddler ages in children with a history of prenatal opioid exposure.

Opioid Use Disorder and Neonatal Opioid Withdrawal Syndrome in Rural Environments

Rural communities in the United States have seen a steep rise in opioid use disorder (OUD) during pregnancy, with a parallel increase in neonatal opioid withdrawal syndrome (NOWS). The birthing person-infant dyads affected by OUD and NOWS in rural areas face many barriers to accessing care. Innovative approaches have proven successful in improving health outcomes for affected birthing persons and newborns, but more work is needed to continue to improve access to prevention, treatment, and additional support services for this vulnerable population.

Psychological distress among postpartum women who took opioids during pregnancy: the role of perceived stigma in healthcare settings

This study examined the relationship between perceived stigma in healthcare settings during pregnancy and psychological distress and well-being in the postpartum period among individuals who took opioids while pregnant. Analyses included 134 birth mothers of opioid-exposed infants. At 0-1 months postpartum, perceived stigma and psychological distress were measured using the Prenatal Opioid use Perceived Stigma scale and measures from the Patient-Reported Outcome Measurement Information System (PROMIS). Food insecurity, housing instability, and Adverse Childhood Experiences (ACEs) were also assessed. Linear and generalized linear mixed-effect models were conducted to compare PROMIS scale scores and unmet needs by stigma, adjusting for site/location, age, race/ethnicity, marital status, education, public insurance, and parity. More than half of participants (54%) perceived stigma in healthcare settings. Individuals reporting stigma had higher depression, anxiety, and anger scores (p < 0.001) indicating greater psychological distress in the postpartum period compared to those reporting no stigma, after controlling for demographic characteristics. In addition, they scored significantly lower on the PROMIS meaning and purpose scale, an indicator of well-being (p = 0.002). Those reporting stigma were more likely to have food insecurity (p = 0.003), three or more ACEs (p = 0.040), verbal or physical abuse during pregnancy (p < 0.001), and less emotional support (p = 0.006) than those who did not. An association was observed between perceived stigma in the prenatal period and psychological distress in the postpartum period, providing support for stigma reduction interventions and education for healthcare providers on trauma-informed care.

Advances in the Care of Infants With Prenatal Opioid Exposure and Neonatal Opioid Withdrawal Syndrome

A significant number of advances have been made in the last 5 years with respect to the identification, diagnosis, assessment, and management of infants with prenatal opioid exposure and neonatal opioid withdrawal syndrome (NOWS) from birth to early childhood. The primary objective of this review is to summarize major advances that will inform the clinical management of opioid-exposed newborns and provide an overview of NOWS care to promote the implementation of best practices. First, advances with respect to standardizing the clinical diagnosis of NOWS will be reviewed. Second, the most commonly used assessment strategies are discussed, with a focus on presenting new quality improvement and clinical trial data surrounding the use of the new function-based assessment Eat, Sleep, and Console approach. Third, both nonpharmacologic and pharmacologic treatment modalities are reviewed, highlighting clinical trials that have compared the use of higher calorie and low lactose formula, vibrating crib mattresses, morphine compared with methadone, buprenorphine compared with morphine or methadone, the use of ondansetron as a medication to prevent the need for NOWS opioid pharmacologic treatment, and the introduction of symptom-triggered dosing compared with scheduled dosing. Fourth, maternal, infant, environmental, and genetic factors that have been found to be associated with NOWS severity are highlighted. Finally, emerging recommendations on postdelivery hospitalization follow-up and developmental surveillance are presented, along with highlighting ongoing and needed areas of research to promote infant and family well-being for families impacted by opioid use.

Molecular and long-term behavioral consequences of neonatal opioid exposure and withdrawal in mice

Introduction

Infants exposed to opioids in utero are at high risk of exhibiting Neonatal Opioid Withdrawal Syndrome (NOWS), a combination of somatic withdrawal symptoms including high pitched crying, sleeplessness, irritability, gastrointestinal distress, and in the worst cases, seizures. The heterogeneity of in utero opioid exposure, particularly exposure to polypharmacy, makes it difficult to investigate the underlying molecular mechanisms that could inform early diagnosis and treatment of NOWS, and challenging to investigate consequences later in life.

Methods

To address these issues, we developed a mouse model of NOWS that includes gestational and post-natal morphine exposure that encompasses the developmental equivalent of all three human trimesters and assessed both behavior and transcriptome alterations.

Results

Opioid exposure throughout all three human equivalent trimesters delayed developmental milestones and produced acute withdrawal phenotypes in mice reminiscent of those observed in infants. We also uncovered different patterns of gene expression depending on the duration and timing of opioid exposure (3-trimesters, in utero only, or the last trimester equivalent only). Opioid exposure and subsequent withdrawal affected social behavior and sleep in adulthood in a sex-dependent manner but did not affect adult behaviors related to anxiety, depression, or opioid response.

Discussion

Despite marked withdrawal and delays in development, long-term deficits in behaviors typically associated with substance use disorders were modest. Remarkably, transcriptomic analysis revealed an enrichment for genes with altered expression in published datasets for Autism Spectrum Disorders, which correlate well with the deficits in social affiliation seen in our model. The number of differentially expressed genes between the NOWS and saline groups varied markedly based on exposure protocol and sex, but common pathways included synapse development, the GABAergic and myelin systems, and mitochondrial function.