Epigenome-wide association study of placental co-methylated regions in newborns for prenatal opioid exposure

Knowledge of health outcomes among opioid-exposed infants is limited, particularly for those not diagnosed with neonatal opioid withdrawal syndrome (NOWS). To describe infant mortality among opioid-exposed infants and identify how mortality risk differs in opioid-exposed infants with and without a diagnosis of NOWS compared with infants without opioid exposure. A retrospective cohort study of maternal-infant dyads was conducted, linking health care claims with vital records for births from January 1, 2010, to December 31, 2014, with follow-up of infants until age 1 year (through 2015). Maternal-infant dyads were included if the infant was born in Texas at 22 to 43 weeks' gestational age to a woman aged 15 to 44 years insured by Texas Medicaid. Data analysis was performed from May 2019 to October 2020. The primary exposure was prenatal opioid exposure, with infants stratified by the presence or absence of a diagnosis of NOWS during the birth hospitalization. Risk of infant mortality (death at age <365 days) was examined using Kaplan-Meier and log-rank tests. A series of logistic regression models was estimated to determine associations between prenatal opioid exposure and mortality, adjusting for maternal and neonatal characteristics and clustering infants at the maternal level to account for statistical dependence owing to multiple births during the study period. Among 1 129 032 maternal-infant dyads, 7207 had prenatal opioid exposure, including 4238 diagnosed with NOWS (mean [SD] birth weight, 2851 [624] g) and 2969 not diagnosed with NOWS (mean [SD] birth weight, 2971 [639] g). Infant mortality was 20 per 1000 live births for opioid-exposed infants not diagnosed with NOWS, 11 per 1000 live births for infants with NOWS, and 6 per 1000 live births in the reference group (P < .001). After adjusting for maternal and neonatal characteristics, mortality in infants with a NOWS diagnosis was not significantly different from the reference population (odds ratio, 0.82; 95% CI, 0.58-1.14). In contrast, the odds of mortality in opioid-exposed infants not diagnosed with NOWS was 72% greater than the reference population (odds ratio, 1.72; 95% CI, 1.25-2.37). In this study, opioid-exposed infants appeared to be at increased risk of mortality, and the treatments and supports provided to those diagnosed with NOWS may be protective. Interventions to support opioid-exposed maternal-infant dyads are warranted, regardless of the perceived severity of neonatal opioid withdrawal.

The assessment of opioid withdrawal in the neonate, or neonatal opioid withdrawal syndrome (NOWS), is problematic because current assessment methods are based on subjective observer ratings. Crying is a distinctive component of NOWS assessment tools and can be measured objectively using acoustic analysis. To evaluate the feasibility of using newborn cry acoustics (acoustics referring to the physical properties of sound) as an objective biobehavioral marker of NOWS. This prospective controlled cohort study assessed whether acoustic analysis of neonate cries could predict which infants would receive pharmacological treatment for NOWS. A total of 177 full-term neonates exposed and not exposed to opioids were recruited from Women & Infants Hospital of Rhode Island between August 8, 2016, and March 18, 2020. Cry recordings were processed for 118 neonates, and 65 neonates were included in the final analyses. Neonates exposed to opioids were monitored for signs of NOWS using the Finnegan Neonatal Abstinence Scoring Tool administered every 3 hours as part of a 5-day observation period during which audio was recorded continuously to capture crying. Crying of healthy neonates was recorded before hospital discharge during routine handling (eg, diaper changes). The primary exposure was prenatal opioid exposure as determined by maternal receipt of medication-assisted treatment with methadone or buprenorphine. Neonates were stratified by prenatal opioid exposure and receipt of pharmacological treatment for NOWS before discharge from the hospital. In total, 775 hours of audio were collected and trimmed into 2.5 hours of usable cries, then acoustically analyzed (using 2 separate acoustic analyzers). Cross-validated supervised machine learning methods (combining the Boruta algorithm and a random forest classifier) were used to identify relevant acoustic parameters and predict pharmacological treatment for NOWS. Final analyses included 65 neonates (mean [SD] gestational age at birth, 36.6 [1.1] weeks; 36 [55.4%] female; 50 [76.9%] White) with usable cry recordings. Of those, 19 neonates received pharmacological treatment for NOWS, 7 neonates were exposed to opioids but did not receive pharmacological treatment for NOWS, and 39 healthy neonates were not exposed to opioids. The mean of the predictions of random forest classifiers predicted receipt of pharmacological treatment for NOWS with high diagnostic accuracy (area under the curve, 0.90 [95% CI, 0.83-0.98]; accuracy, 0.85 [95% CI, 0.74-0.92]; sensitivity, 0.89 [95% CI, 0.67-0.99]; specificity, 0.83 [95% CI, 0.69-0.92]). In this study, newborn acoustic cry analysis had potential as an objective measure of opioid withdrawal. These findings suggest that acoustic cry analysis using machine learning could improve the assessment, diagnosis, and management of NOWS and facilitate standardized care for these infants.

Prenatal opioid exposure (POE) is a growing public health concern due to its associated adverse outcomes including neonatal opioid withdrawal syndrome (NOWS). The aim of this study was to assess alterations in thalamic functional connectivity in neonates with POE using resting-state functional magnetic resonance imaging (rs-fMRI) and identify whether these altered connectivity measures were associated with NOWS severity. In this prospective, IRB-approved study, we performed rs-fMRI in 19 infants with POE and 20 healthy control infants without POE. Following standard pre-processing, we performed seed-based functional connectivity analysis with the right and left thalamus as the regions of interest. We performed post hoc analysis in the prenatal opioid exposure group to identifyassociations of altered thalamocorticalconnectivity with severity of NOWS. P value of < .05 was considered statistically significant. There were several regions of significantly altered thalamic to cortical functionalconnectivity in infants with POEcompared to the healthy infants. Distinct regions of thalamocorticalfunctional connectivity correlated with maximum modifiedFinnegan score. Association between thalamocortical connectivity and severity of NOWS was nominally modified by maternal psychological conditions and polysubstance use. Our findings reveal prenatal opioid exposure-related alterations in thalamic functional connectivity in the infant brain that are correlated with severity of NOWS. Future studies may benefit from evaluation of thalamocortical resting state functional connectivity in infants with POE tohelp stratify risk of long termneurodevelopmental outcomes.

To evaluate the association between prenatal prescription opioid analgesic exposure (duration, timing) and neonatal opioid withdrawal syndrome (NOWS). We conducted a retrospective cohort study of Wisconsin Medicaid-covered singleton live births from 2011 to 2019. The primary outcome was a NOWS diagnosis in the first 30 days of life. Opioid exposure was identified with any claim for prescription opioid analgesic fills during pregnancy. We measured exposure duration cumulatively in days (1-6, 7-29, 30-89, and 90 or more) and identified timing as early (first two trimesters only) or late (third trimester, regardless of earlier pregnancy use). We used logistic regression modeling to assess NOWS incidence by exposure duration and timing, with and without propensity score matching. Overall, 31,456 (14.3%) of 220,570 neonates were exposed to prescription opioid analgesics prenatally. Among exposed neonates, 19,880 (63.2%) had 1-6 days of exposure, 7,694 (24.5%) had 7-29 days, 2,188 (7.0%) had 30-89 days, and 1,694 (5.4%) had 90 or more days of exposure; 15,032 (47.8%) had late exposure. Absolute NOWS incidence among neonates with 1-6 days of exposure was 7.29 per 1,000 neonates (95% CI 6.11-8.48), and incidence increased with longer exposure: 7-29 days (19.63, 95% CI 16.53-22.73); 30-89 days (58.96, 95% CI 49.08-68.84); and 90 or more days (177.10, 95% CI 158.90-195.29). Absolute NOWS incidence for early and late exposures were 11.26 per 1,000 neonates (95% CI 9.65-12.88) and 35.92 per 1,000 neonates (95% CI 32.95-38.90), respectively. When adjusting for confounders including timing of exposure, neonates exposed for 1-6 days had no increased odds of NOWS compared with unexposed neonates, whereas those exposed for 30 or more days had increased odds of NOWS (30-89 days: adjusted odds ratio [aOR] 2.15, 95% CI 1.22-3.79; 90 or more days: 2.80, 95% CI 1.36-5.76). Late exposure was associated with elevated odds of NOWS (aOR 1.57, 95% CI 1.25-1.96) when compared with unexposed after adjustment for exposure duration. More than 30 days of prenatal prescription opioid exposure was associated with NOWS regardless of exposure timing. Third-trimester opioid exposure, irrespective of exposure duration, was associated with NOWS.

Differences in withdrawal symptoms, microglia activity, and cognitive functioning in rats exposed to continuous low-dose heroin in-utero

Determine the accuracy of diagnostic codes in identifying Prenatal Opioid Exposure (POE) and Neonatal Opioid Withdrawal Syndrome (NOWS). A cross-sectional study of 374,222 mother-infant dyads with delivery from 01/01/2010 to 12/31/2019. We ascertained maternal diagnostic codes for opioid use during pregnancy and infant diagnostic codes for drug exposure and withdrawal. We assessed sensitivity and positive predictive value (PPV) for POE and NOWS, defined using laboratory, pharmacy, and clinical data. Maternal codes had low sensitivity (36.4%) and PPV (34.7%) for POE. Infant codes for drug exposure were neither sensitive for POE (14%) nor NOWS (31.6%) and had low PPV. Codes for newborn withdrawal had low sensitivity (31.6%) for detecting NOWS, but high PPV (85%). Sensitivity improved (95.1%) for NOWS requiring pharmacologic treatment. Diagnostic codes identify POE and NOWS poorly. Improved case identification would include pharmacy and laboratory results, and clearly defined criteria for evidence of withdrawal.

Little is known about the short- and long-term effects of prenatal opioid exposure on infant neurodevelopment. Infants with neonatal opioid withdrawal syndrome (NOWS) are often admitted to neonatal intensive care units (NICU) where the development of coregulation between mothers and infants is easily disrupted. Understanding early mother-infant coregulation is needed to guide intervention strategies for these high-risk mother-infant dyads. Explore the impact of prenatal opioid exposure on mother-infant coregulation, as an indicator of early infant neurodevelopment, in response to a standardized stress experiment, the Still Face Paradigm (SFP). A prospective cohort design was used to enroll opioid-exposed (N=11) and non-exposed (N=13) mother-infant dyads, when infants discharged from the NICU were 6 to 9months. Dyadic heart rate variability (HRV) data were used as a measure of coregulation and were recorded using heart rate monitors during the 3 phases of the SFP: (a) baseline, (b) still-face, or flat affect, and (c) reunion. We conducted analyses to determine differences within the HRV dyad profiles. HRV profiles differed between the 2 study groups. In the opioid-exposed group: (a) infants exhibited more irregular autonomic processes, (b) mothers had higher HRV baselines, and (c) there was an overall dysregulation between mothers and infants compared to the non-opioid exposed group. These differences may suggest that prenatal opioid exposure contributes to difficulty with dyadic co-regulation which may negatively impact early infant neurodevelopment. Additional research is needed to better understand the role of prenatal opioid exposure in infant neurodevelopment.

The increasing use of opioids in pregnant women has led to an alarming rise in the number of cases of neonates with drug-induced withdrawal symptoms known as neonatal opioid withdrawal syndrome (NOWS). NOWS is a toxic heterogeneous condition with many neurologic, autonomic, and gastrointestinal symptoms including poor feeding, irritability, tachycardia, hypertension, respiratory defects, tremors, hyperthermia, and weight loss. Paradoxically, for the management of NOWS, low doses of morphine, methadone, or buprenorphine are administered. NOWS is a polygenic disorder supported by studies of genomic variation in opioid-related genes. Single-nucleotide polymorphisms (SNPs) in CYP2B6 are associated with variations in NOWS infant responses to methadone and SNPs in the OPRM1, ABCB1, and COMT genes are associated with need for treatment and length of hospital stay. Epigenetic gene changes showing higher methylation levels in infants and mothers have been associated with more pharmacologic treatment in the case of newborns, and for mothers, longer infant hospital stays. Respiratory disturbances associated with NOWS are not well characterized. Little is known about the effects of opioids on developing neonatal respiratory control and respiratory distress (RD), a potential problem for survival of the neonate. In a rat model to test the effect of maternal opioids on the developing respiratory network and neonatal breathing, maternal-derived methadone increased apneas and lessened RD in neonates at postnatal (P) days P0 and P1. From P3, breathing normalized with age suggesting reorganization of respiratory rhythm-generating circuits at a time when the preBötC becomes the dominant inspiratoryrhythm generator. In medullary slices containing the preBötC, maternal opioid treatment plus exposure to exogenous opioids showed respiratory activity was maintained in younger but not older neonates. Thus, maternal opioids blunt centrally controlled respiratory frequency responses to exogenous opioids in an age-dependent manner. In the absence of maternal opioid treatment, exogenous opioids abolished burst frequencies at all ages. Prenatal opioid exposure in children stunts growth rate and development while studies of behavior and cognitive ability reveal poor performances. In adults, high rates of attention deficit disorder, hyperactivity, substance abuse, and poor performances in intelligence and memory tests have been reported.

Sex-Dependent Gene Expression in Infants with Neonatal Opioid Withdrawal Syndrome

In recent years, there has been a sixfold increase in the number of pregnant people with opioid use disorder (OUD). Rates of neonatal opioid withdrawal syndrome (NOWS), previously known as neonatal abstinence syndrome (NAS), have significantly increased in virtually every state and demographic group(HealthcareCostUtilizationProject,HCUP,2010). NOWS is a condition resulting from chronic exposure to either therapeutic opioid use (e.g., medication for OUD, chronic pain conditions) or nonprescribed opioid use. To date, there is no known prenatal treatment to help decrease the risk of infants developing NOWS and subsequent neurodevelopmental outcomes. Given the increasing support for how placental signaling, or placental programming, may play a role in downstream pathology, prospective research investigating how the placenta is affected by chronic opioid exposure morphologically, histologically, and at the cellular level may open up potential treatment opportunities in this field. In this review, we discuss literature exploring the physiological roles of nitric oxide and dopamine not only in the vascular development of the placenta, but also in fetal cerebral blood flow, neurogenesis, neuronal differentiation, and neuronal activity. We also discuss histological preclinical studies that suggest chronic opioid exposure to induce some combination of placental dysfunction and hypoxia in a manner similar to other well-known placental pathologies, as denoted by the compensatory neovascularization and increased utilization of the placenta's supply of trophoblast cells, which play an essential role in placental angiogenesis. Overall, we found that the current literature, while limited, suggests chronic opioid exposure negatively impacts placental function and fetal brain development on a cellular and histopathological level. We conclude that it is worthwhile to consider the placenta as a therapeutic target with the ultimate goal of decreasing the incidence of NOWS and the long-term impacts of prenatal opioid exposure.

Opioid withdrawal behavior in spiny mice: A novel preclinical model of neonatal opioid withdrawal syndrome (NOWS)

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.

BackgroundInfants with prenatal opioid and substance exposure are at higher risk of poor neurobehavioral outcomes in later childhood. Early brain imaging in infancy has the potential to identify early brain developmental alterations that may help predict behavioral outcomes in these children. In this study, using resting-state functional MRI in early infancy, we aim to identify differences in global brain network connectivity in infants with prenatal opioid and substance exposure compared to healthy control infants.Methods and MaterialsIn this prospective study, we recruited 23 infants with prenatal opioid exposure and 29 healthy opioid naïve infants. All subjects underwent brain resting-state functional MRI before 3 months postmenstrual age. Covariate Assisted Principal (CAP) regression was performed to identify brain networks within which functional connectivity was associated with opioid exposure after adjusting for sex and gestational age. Associations of these significant networks with maternal comorbidities were also evaluated. Additionally, graph network metrics were assessed in these CAP networks.ResultsThere were four CAP network components that were significantly different between the opioid exposed and healthy control infants. Two of these four networks were associated with maternal psychological factors. Intra-network graph metrics, namely average flow coefficient, clustering coefficient and transitivity were also significantly different in opioid exposed infants compared to healthy controls.ConclusionPrenatal opioid exposure is associated with alterations in global brain functional networks compared to non-opioid exposed infants, with intra-network alterations in graph network modeling. These network alterations were also associated with maternal comorbidity, especially mental health. Large-scale longitudinal studies can help in understanding the clinical implications of these early brain functional network alterations in infants with prenatal opioid exposure.

Neonatal opioid withdrawal syndrome (NOWS) describes infants' withdrawal signs and symptoms after birth due to an interruption of prenatal opioid exposure. Many infants with NOWS are also exposed to nonopioids, however. This study was to determine hospital outcomes of infants exposed to opioids alone or coexposed with nonopioid substances (polysubstance). We reviewed infants of ≥34 weeks of gestation with prenatal opioid exposure from April 2015 to May 2018. We compared the median lengths of stay (LOS) and treatment (LOT) and the percentages of infants requiring pharmacologic and adjunctive treatment in infants exposed to opioids alone or polysubstance. We used Wilcoxon's test for continuous outcomes or Chi-squared test for categorical outcomes to determine statistical significance. We used multivariable regression model to calculate each drug category's estimates of adjusted mean ratios for LOS and LOT plus estimates of adjusted odds ratios for pharmacologic/adjunctive treatments. Of the 175 infants, 33 (19%) infants had opioid exposure alone. Opioid exposure included short- and/or long-acting opioids. A total of 142 (81%) had polysubstance exposure with 47% of mothers using nicotine products. We saw similar hospital outcomes between infants exposed to opioids alone or polysubstance; however, a higher percentage of infants with both short- and long-acting opioid exposure required pharmacologic treatment compared with either opioid alone. Focusing on individual drug categories, we detected differential hospital outcomes in which short-acting opioids decreased LOT, whereas long-acting opioids increased LOS, LOT, and need for pharmacologic and adjunctive treatment. Coexposure of opioids with stimulants decreased LOT and reduced need for adjunctive treatment. Coexposures with antidepressants increased LOT, while with antiepilepetics increased LOS. Because infants with NOWS often have coexposures to other nonopioid substances, appreciating the associated risks of individual or combination of drugs in modulating hospital outcomes may help counsel families on their infants' expected hospital course. · Hospital outcomes were similar between infants exposed to opioids alone or polysubstance including opioids.. · Infants with short- and long-acting opioids required pharmacologic treatment more often than either opioid alone.. · Differential hospital outcomes exist for various co-exposures of opioids with nonopioids..

Parental drug abuse and dysfunctional households during childhood increase the risk for cardiovascular disease (CVD) later in life. Chronic opioid exposure and opioid use disorder (OUD) are associated with a 2-fold increased risk of CVD and a 16% increase in coronary artery disease. OUD among pregnant women is an understudied area related to the opioid epidemic, causing a 5-fold increase in neonatal opioid withdrawal syndrome (NOWS) incidence. In former studies, we subjected female rats to two models of maternal opioid exposure: 1) morphine sulfate during gestation or 2) fentanyl citrate during preconception and gestation. At birth, female and male opioid-exposed offspring showed normal birth weight compared with vehicle-exposed offspring while displaying NOWS-like somatic withdrawal signs after parturition. As adults, in utero opioid-exposed offspring displayed increased mean arterial pressure, sympathetic activation, and CVD risk factors. Prenatal exposure to opioids has been shown to dysregulate the endogenous opioid peptides (EOPs) and alter behavioral outcomes later in life, but the transplacental effects of opioids on blood pressure regulation remain understudied. Therefore, this study aimed to assess whether adult offspring with prenatal opioid exposure display changes in 1) the expression of the EOP proenkephalin (PENK) in brain regions known to control the sympathetic outflow (Paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM)), heart, kidneys, and liver; 2) the plasma levels of EOPs (PENK, enkephalin, prodynorphin and dynorphin); and 3) the fentanyl plasma clearance (pharmacokinetics). Protein was extracted from tissues for western blot analysis using the primary antibody for PENK (1:1000, Invitrogen). In opioid-exposed offspring, PENK protein expression was reduced in RVLM (0.55±0.06 vs. 0.36±0.01, AU) and PVN (1.56±0.09 vs. 1.08±0.08, AU), showing a ~35% and ~31% reduction, respectively (n=4-5, p&lt;0.05). In the heart, PENK protein expression was not statistically different in opioid-exposed offspring compared with vehicle-exposed offspring. However, in the kidneys (0.72±0.09 vs. 1.16±0.10, AU) and liver (0.40±0.06 vs. 0.60±0.05, AU), PENK protein expression showed a 61% and 50% increase only in male opioid-exposed offspring compared to vehicle-exposed offspring (n=6-8, p&lt;0.05). None of the plasma circulating EOP levels measured by ELISA were affected by prenatal opioid exposure. Fentanyl clearance in plasma (0, 15, 30, 60, 120, 360,1440 mins) following a fentanyl injection (20ug/kg, sc.) was not different between adult vehicle and opioid-exposed offspring, indicating potential pharmacodynamic alterations secondary to prenatal opioid exposure. As EOPs exert inhibitory effects on adrenergic signaling, our data indicate that prenatal exposure to opioids may induce a permanent downregulation of EOPs in the central nervous system and thus contributing to increasing the sympathetic tone and desensitize the acute depressor responses to opioid peptides, suggesting that EOPs may be critical for blood pressure regulation. However, peripheral expression of PENK seems to reflect pathophysiological alterations in different tissues since elevated PENK level is used in clinical settings as a marker to assess the severity of tissue damage in the liver and kidneys. This study was funded by 1013177615 (NRPA-UK), 1013400001 (SUGAR-UK) and 1013171360 (DPNS-UK). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.