Differences in the profile of neonatal abstinence syndrome signs in methadone- versus buprenorphine-exposed neonates

The effects of buprenorphine and morphine during pregnancy: Impact of exposure length on maternal brain, behavior, and offspring neurodevelopment

The escalating incidence of opioid-related issues among pregnant women in the United States underscores the critical necessity to understand the effects of opioid use and Medication for Opioid Use Disorders (MOUDs) during pregnancy. This research employed a translational rodent model to examine the impact of gestational exposure to buprenorphine (BUP) or morphine on maternal behaviors and offspring well-being. Female rats received BUP or morphine before conception, representing established use, with exposure continuing until postnatal day 2 or discontinued on gestational day 19 to mimic treatment cessation before birth. Maternal behaviors - including care, pup retrieval, and preference - as well as hunting behaviors and brain neurotransmitter levels were assessed. Offspring were evaluated for mortality, weight, length, milk bands, surface righting latency, withdrawal symptoms, and brain neurotransmitter levels. Our results reveal that regardless of exposure length (i.e., continued or discontinued), BUP resulted in reduced maternal care in contrast to morphine-exposed and control dams. Opioid exposure altered brain monoamine levels in the dams and offspring, and was associated with increased neonatal mortality, reduced offspring weight, and elevated withdrawal symptoms compared to controls. These findings underscore BUP's potential disruption of maternal care, contributing to increased pup mortality and altered neurodevelopmental outcomes in the offspring. This study calls for more comprehensive research into prenatal BUP exposure effects on the maternal brain and infant development with the aim to mitigate adverse outcomes in humans exposed to opioids during pregnancy.

Investigating the neurobiology of maternal opioid use disorder and prenatal opioid exposure using brain organoid technology

Over the past two decades, Opioid Use Disorder (OUD) among pregnant women has become a major global public health concern. OUD has been characterized as a problematic pattern of opioid use despite adverse physical, psychological, behavioral, and or social consequences. Due to the relapsing-remitting nature of this disorder, pregnant mothers are chronically exposed to exogenous opioids, resulting in adverse neurological and neuropsychiatric outcomes. Collateral fetal exposure to opioids also precipitates severe neurodevelopmental and neurocognitive sequelae. At present, much of what is known regarding the neurobiological consequences of OUD and prenatal opioid exposure (POE) has been derived from preclinical studies in animal models and postnatal or postmortem investigations in humans. However, species-specific differences in brain development, variations in subject age/health/background, and disparities in sample collection or storage have complicated the interpretation of findings produced by these explorations. The ethical or logistical inaccessibility of human fetal brain tissue has also limited direct examinations of prenatal drug effects. To circumvent these confounding factors, recent groups have begun employing induced pluripotent stem cell (iPSC)-derived brain organoid technology, which provides access to key aspects of cellular and molecular brain development, structure, and function in vitro. In this review, we endeavor to encapsulate the advancements in brain organoid culture that have enabled scientists to model and dissect the neural underpinnings and effects of OUD and POE. We hope not only to emphasize the utility of brain organoids for investigating these conditions, but also to highlight opportunities for further technical and conceptual progress. Although the application of brain organoids to this critical field of research is still in its nascent stages, understanding the neurobiology of OUD and POE via this modality will provide critical insights for improving maternal and fetal outcomes.

Lipophilic analogues of D-cysteine prevent and reverse physical dependence to fentanyl in male rats

We examined whether co-injections of the cell-permeant D-cysteine analogues, D-cysteine ethyl ester (D-CYSee) and D-cysteine ethyl amide (D-CYSea), prevent acquisition of physical dependence induced by twice-daily injections of fentanyl, and reverse acquired dependence to these injections in freely-moving male Sprague Dawley rats. Injection of the opioid receptor antagonist, naloxone HCl (NLX, 1.5 mg/kg, IV), elicited a series of withdrawal phenomena that included cardiorespiratory and behavioral responses, and falls in body weight and body temperature, in rats that received 5 or 10 injections of fentanyl (125 μg/kg, IV), and the same number of vehicle co-injections. Regarding the development of physical dependence, the NLX-precipitated withdrawal phenomena were markedly reduced in fentanyl-injected rats that had received co-injections of D-CYSee (250 μmol/kg, IV) or D-CYSea (100 μmol/kg, IV), but not D-cysteine (250 μmol/kg, IV). Regarding reversal of established dependence to fentanyl, the NLX-precipitated withdrawal phenomena in rats that had received 10 injections of fentanyl (125 μg/kg, IV) was markedly reduced in rats that received co-injections of D-CYSee (250 μmol/kg, IV) or D-CYSea (100 μmol/kg, IV), but not D-cysteine (250 μmol/kg, IV), starting with injection 6 of fentanyl. This study provides evidence that co-injections of D-CYSee and D-CYSea prevent the acquisition of physical dependence, and reverse acquired dependence to fentanyl in male rats. The lack of effect of D-cysteine suggests that the enhanced cell-penetrability of D-CYSee and D-CYSea into cells, particularly within the brain, is key to their ability to interact with intracellular signaling events involved in acquisition to physical dependence to fentanyl.

Neonatal Abstinence Signs during Treatment: Trajectory, Resurgence and Heterogeneity

Neonatal abstinence syndrome (NAS) presents with a varying severity of withdrawal signs and length of treatment (LOT). We examined the course and relevance of each of the NAS withdrawal signs during treatment in a sample of 182 infants with any prenatal opioid exposure, gestational age ≥ 35 weeks, without other medical conditions, and meeting the criteria for pharmacological treatment. Infants were monitored using the Finnegan Neonatal Abstinence Scoring Tool. Daily mean Finnegan scores were estimated using linear mixed models with random subject effects to account for repeated withdrawal scores from the same subject. Daily item prevalence was estimated using generalized estimating equations with a within-subject exchangeable correlation structure. The median LOT was 12.86 days. The prevalence of withdrawal signs decreased from day one to day three of treatment. However, certain central nervous system (CNS) and gastrointestinal (GI) signs showed sporadic increases in prevalence notable around two weeks of treatment, accounting for increases in Finnegan scores that guided pharmacotherapy. We question whether the resurgence of signs with a prolonged LOT is mainly a consequence of opioid tolerance or withdrawal. Monitoring CNS and GI signs throughout treatment is crucial. Future studies directed to better understand this clinical phenomenon may lead to the refining of NAS pharmacotherapy and perhaps the discovery of treatment alternatives.

Opioid, methamphetamine, and polysubstance use: perinatal outcomes for the mother and infant

The escalation in opioid pain relief (OPR) medications, heroin and fentanyl, has led to an increased use during pregnancy and a public health crisis. Methamphetamine use in women of childbearing age has now eclipsed the use of cocaine and other stimulants globally. Recent reports have shown increases in methamphetamine are selective to opioid use, particularly in rural regions in the US. This report compares the extent of our knowledge of the perinatal outcomes of OPRs, heroin, fentanyl, two long-acting substances used in the treatment of opioid use disorders (buprenorphine and methadone), and methamphetamine. The methodological limitations of the current research are examined, and two important initiatives that will address these limitations are reviewed. Current knowledge of the perinatal effects of short-acting opioids, OPRs, heroin, and fentanyl, is scarce. Most of what we know about the perinatal effects of opioids comes from research on the long-acting opioid agonist drugs used in the treatment of OUDs, methadone and buprenorphine. Both have better perinatal outcomes for the mother and newborn than heroin, but the uptake of these opioid substitution programs is poor (<50%). Current research on perinatal outcomes of methamphetamine is limited to retrospective epidemiological studies, chart reviews, one study from a treatment center in Hawaii, and the US and NZ cross-cultural infant Development, Environment And Lifestyle IDEAL studies. Characteristics of pregnant individuals in both opioid and MA studies were associated with poor maternal health, higher rates of mental illness, trauma, and poverty. Infant outcomes that differed between opioid and MA exposure included variations in neurobehavior at birth which could complicate the diagnosis and treatment of neonatal opioid withdrawal (NOWs). Given the complexity of OUDs in pregnant individuals and the increasing co-use of these opioids with MA, large studies are needed. These studies need to address the many confounders to perinatal outcomes and employ neurodevelopmental markers at birth that can help predict long-term neurodevelopmental outcomes. Two US initiatives that can provide critical research and treatment answers to this public health crisis are the US Environmental influences on Child Health Outcomes (ECHO) program and the Medication for Opioid Use Disorder During Pregnancy Network (MAT-LINK).

L-cysteine ethyl ester prevents and reverses acquired physical dependence on morphine in male Sprague Dawley rats

The molecular mechanisms underlying the acquisition of addiction/dependence on morphine may result from the ability of the opioid to diminish the transport of L-cysteine into neurons via inhibition of excitatory amino acid transporter 3 (EAA3). The objective of this study was to determine whether the co-administration of the cell-penetrant L-thiol ester, L-cysteine ethyl ester (L-CYSee), would reduce physical dependence on morphine in male Sprague Dawley rats. Injection of the opioid-receptor antagonist, naloxone HCl (NLX; 1.5 mg/kg, IP), elicited pronounced withdrawal phenomena in rats which received a subcutaneous depot of morphine (150 mg/kg) for 36 h and were receiving a continuous infusion of saline (20 μL/h, IV) via osmotic minipumps for the same 36 h period. The withdrawal phenomena included wet-dog shakes, jumping, rearing, fore-paw licking, 360° circling, writhing, apneas, cardiovascular (pressor and tachycardia) responses, hypothermia, and body weight loss. NLX elicited substantially reduced withdrawal syndrome in rats that received an infusion of L-CYSee (20.8 μmol/kg/h, IV) for 36 h. NLX precipitated a marked withdrawal syndrome in rats that had received subcutaneous depots of morphine (150 mg/kg) for 48 h) and a co-infusion of vehicle. However, the NLX-precipitated withdrawal signs were markedly reduced in morphine (150 mg/kg for 48 h)-treated rats that began receiving an infusion of L-CYSee (20.8 μmol/kg/h, IV) at 36 h. In similar studies to those described previously, neither L-cysteine nor L-serine ethyl ester (both at 20.8 μmol/kg/h, IV) mimicked the effects of L-CYSee. This study demonstrates that 1) L-CYSee attenuates the development of physical dependence on morphine in male rats and 2) prior administration of L-CYSee reverses morphine dependence, most likely by intracellular actions within the brain. The lack of the effect of L-serine ethyl ester (oxygen atom instead of sulfur atom) strongly implicates thiol biochemistry in the efficacy of L-CYSee. Accordingly, L-CYSee and analogs may be a novel class of therapeutics that ameliorate the development of physical dependence on opioids in humans.

Neonatal Abstinence Syndrome in Infants with Prenatal Exposure to Methadone versus Buprenorphine

Neonatal abstinence syndrome (NAS) has been of increasing concern. Studies suggest that prenatal exposure to buprenorphine may be preferred to methadone in regard to neonatal withdrawal. Our aim was to determine whether the incidence and severity of NAS are different between babies prenatally exposed to methadone or buprenorphine in pregnancy. This retrospective analysis of infants ≥ 35-weeks-old exposed to methadone/buprenorphine alone or in conjunction with other substances in utero. They were divided into four groups: 1-methadone alone (Met), 2-buprenorphine alone (Bup), 3 and 4-those exposed to methadone and buprenorphine, respectively, in conjunction with other drugs (Met+ and Bup+). The frequency of NAS treatment, duration of treatment (LOT) and length of stay (LOS) were compared between groups. Of the 290 mothers, 59% were in the Met group, 18% in the Bup group, 14% in the Met or Bup and another opiate group, and 9% took methadone or buprenorphine plus various other substances. Infants born to Met/Met+ mothers had a four-times higher likelihood of developing NAS (p < 0.001). There was no difference in the LOS (p = 0.08) or LOT (p = 0.11) between groups. The buprenorphine treatment in pregnancy decreased the risk of babies developing NAS. However, once the NAS required pharmacological treatment, the type of maternal prenatal exposure did not affect the LOS or LOT.

Methadone alters transcriptional programs associated with synapse formation in human cortical organoids

Opioid use disorder (OUD) among pregnant women has become an epidemic in the United States. Pharmacological interventions for maternal OUD most commonly involve methadone, a synthetic opioid analgesic that attenuates withdrawal symptoms and behaviors linked with drug addiction. However, evidence of methadone's ability to readily accumulate in neural tissue, and cause long-term neurocognitive sequelae, has led to concerns regarding its effect on prenatal brain development. We utilized human cortical organoid (hCO) technology to probe how this drug impacts the earliest mechanisms of cortico-genesis. Bulk mRNA sequencing of 2-month-old hCOs chronically treated with a clinically relevant dose of 1 μM methadone for 50 days revealed a robust transcriptional response to methadone associated with functional components of the synapse, the underlying extracellular matrix (ECM), and cilia. Co-expression network and predictive protein-protein interaction analyses demonstrated that these changes occurred in concert, centered around a regulatory axis of growth factors, developmental signaling pathways, and matricellular proteins (MCPs). TGFβ1 was identified as an upstream regulator of this network and appeared as part of a highly interconnected cluster of MCPs, of which thrombospondin 1 (TSP1) was most prominently downregulated and exhibited dose-dependent reductions in protein levels. These results demonstrate that methadone exposure during early cortical development alters transcriptional programs associated with synaptogenesis, and that these changes arise by functionally modulating extra-synaptic molecular mechanisms in the ECM and cilia. Our findings provide novel insight into the molecular underpinnings of methadone's putative effect on cognitive and behavioral development and a basis for improving interventions for maternal opioid addiction.

Buprenorphine versus Methadone for Opioid Use Disorder in Pregnancy

BACKGROUND

Opioid agonist therapy is strongly recommended for pregnant persons with opioid use disorder. Buprenorphine may be associated with more favorable neonatal and maternal outcomes than methadone, but existing data are limited.

METHODS

We conducted a cohort study involving pregnant persons who were enrolled in public insurance programs in the United States during the period from 2000 through 2018 in which we examined outcomes among those who received buprenorphine as compared with those who received methadone. Exposure to the two medications was assessed in early pregnancy (through gestational week 19), late pregnancy (gestational week 20 through the day before delivery), and the 30 days before delivery. Risk ratios for neonatal and maternal outcomes were adjusted for confounders with the use of propensity-score overlap weights.

RESULTS

The data source for the study consisted of 2,548,372 pregnancies that ended in live births. In early pregnancy, 10,704 pregnant persons were exposed to buprenorphine and 4387 to methadone. In late pregnancy, 11,272 were exposed to buprenorphine and 5056 to methadone (9976 and 4597, respectively, in the 30 days before delivery). Neonatal abstinence syndrome occurred in 52.0% of the infants who were exposed to buprenorphine in the 30 days before delivery as compared with 69.2% of those exposed to methadone (adjusted relative risk, 0.73; 95% confidence interval [CI], 0.71 to 0.75). Preterm birth occurred in 14.4% of infants exposed to buprenorphine in early pregnancy and in 24.9% of those exposed to methadone (adjusted relative risk, 0.58; 95% CI, 0.53 to 0.62); small size for gestational age in 12.1% and 15.3%, respectively (adjusted relative risk, 0.72; 95% CI, 0.66 to 0.80); and low birth weight in 8.3% and 14.9% (adjusted relative risk, 0.56; 95% CI, 0.50 to 0.63). Delivery by cesarean section occurred in 33.6% of pregnant persons exposed to buprenorphine in early pregnancy and 33.1% of those exposed to methadone (adjusted relative risk, 1.02; 95% CI, 0.97 to 1.08), and severe maternal complications developed in 3.3% and 3.5%, respectively (adjusted relative risk, 0.91; 95% CI, 0.74 to 1.13). Results of exposure in late pregnancy were consistent with results of exposure in early pregnancy.

CONCLUSIONS

The use of buprenorphine in pregnancy was associated with a lower risk of adverse neonatal outcomes than methadone use; however, the risk of adverse maternal outcomes was similar among persons who received buprenorphine and those who received methadone. (Funded by the National Institute on Drug Abuse.).

Central Nervous System Distribution of Buprenorphine in Pregnant Sheep, Fetuses and Newborn Lambs After Continuous Transdermal and Single Subcutaneous Extended-Release Dosing

Buprenorphine is used during pregnancy for the treatment of opioid use disorder. Limited data exist on the central nervous system (CNS) permeation and distribution, and on the fetal exposure to buprenorphine. The aim of our study was to determine the extent of buprenorphine distribution to CNS in the pregnant sheep, and their fetus at steady-state, and their newborn lambs postdelivery, using three different dosing regimens. Twenty-eight pregnant ewes in late gestation received buprenorphine via 7-day transdermal patch releasing buprenorphine 20 µg/h (n=9) or 40 µg/h (n=11), or an extended-release 8 mg/week subcutaneous injection (n=8). Plasma, cerebrospinal fluid, and CNS tissue samples were collected at steady-state from ewes and fetuses, and from lambs 0.33 - 45 hours after delivery. High accumulation of buprenorphine was observed in all CNS tissues. The median CNS/plasma concentration -ratios of buprenorphine in different CNS areas ranged between 13 and 50 in the ewes, and between 26 and 198 in the fetuses. In the ewes the CNS/plasma -ratios were similar after the three dosing regimens, but higher in the fetuses in the 40 µg/h dosing group, medians 65 - 122, than in the 20 µg/h group, medians 26 - 54. The subcutaneous injection (theoretical release rate 47.6 µg/h) produced higher concentrations than observed after 40 µg/h transdermal patch dosing. The median fetal/maternal concentration -ratios in different dosing groups ranged between 0.21 and 0.54 in plasma, and between 0.38 and 1.3 in CNS tissues, respectively, with the highest ratios observed in the spinal cord. Buprenorphine concentrations in the cerebrospinal fluid were 8 - 13 % of the concurrent plasma concentration in the ewes and 28 % in the fetuses. Buprenorphine was quantifiable in the newborn lambs' plasma and CNS tissues two days postdelivery. Norbuprenorphine was analyzed from all plasma, cerebrospinal fluid, and CNS tissue samples but was nondetectable or below the LLOQ in most. The current study demonstrates that buprenorphine accumulates into CNS tissues at much higher concentrations than in plasma in pregnant sheep, fetuses, and their newborn lambs even 45 hours after delivery.

Reconceptualizing non-pharmacologic approaches to Neonatal Abstinence Syndrome (NAS) and Neonatal Opioid Withdrawal Syndrome (NOWS): A theoretical and evidence-based approach

Discussions about non-pharmacologic interventions for Neonatal Abstinence Syndrome and Neonatal Opioid Withdrawal Syndrome (NAS/NOWS) have been minor compared with wider attention to pharmacologic treatments. Although historically under-recognized, non-pharmacologic interventions are of paramount importance for all substance-exposed infants and remain as a first line therapy for the care of infants affected by NAS. Here we examine the role of non-pharmacologic interventions for NAS/NOWS by incorporating theoretical perspectives from different disciplines that inform the importance of individualized assessment of the mother-caregiver/infant dyad and interventions that involve both individuals. NAS/NOWS is a complex, highly individualized constellation of signs/symptoms that vary widely in onset, duration, severity, expression, responses to treatment and influence on long-term outcomes. NAS/NOWS often occurs in infants with multiple prenatal/postnatal factors that can compromise neurobiological self-regulatory functioning. We propose to rethink some of the long-held assumptions, beliefs, and paradigms about non-pharmacologic care of the infant with NAS/NOWS, which is provided as non-specific or as "bundled" in current approaches. This paper is Part I of a two-part series on re-conceptualizing non-pharmacologic care for NAS/NOWS as individualized treatment of the dyad. Here, we set the foundation for a new treatment approach grounded in developmental theory and evidence-based observations of infant neurobiology and neurodevelopment. In Part II, we provide actionable, individually tailored evaluations and approaches to non-pharmacologic NAS/NOWS treatment based on measurable domains of infant neurobehavioral functioning.

MATERNAL AND FETAL BUPRENORPHINE PHARMACOKINETICS IN PREGNANT SHEEP DURING TRANSDERMAL PATCH DOSING: Buprenorphine pharmacokinetics in pregnant sheep

BACKGROUND

Buprenorphine is used in the opioid maintenance treatment for opioid dependent patients, including pregnant women. Despite the wide use, limited data exists on buprenorphine pharmacokinetics and fetal exposure during pregnancy. The aim of our study was to determine the buprenorphine pharmacokinetics during transdermal patch dosing to pregnant sheep and, to determine the extent of transplacental transfer of buprenorphine to the fetus.

METHODS

Pregnant sheep in late gestation (n=50) received 20, 25 or 40 µg/h of buprenorphine as a 7-day extended-release transdermal patch. Plasma samples were collected from the ewe and the fetus on days 1 - 6, and buprenorphine and norbuprenorphine concentrations were determined. During the exposure period the sheep had a surgical procedure on the second day, a recovery phase, and an experimental procedure on the sixth day. In the experiment, hypoxia was induced under anesthesia for 18 sheep to investigate if decreased fetal pH would cause ion-trapping of buprenorphine in the fetus. The fetal/maternal plasma concentration ratio was determined on the second and on the sixth exposure day at baseline and during hypoxia. Maternal pharmacokinetics were modelled with a population pharmacokinetic method using the data from this study and our previous intravenous administration study.

RESULTS

The transdermal patch provided an extended release of buprenorphine throughout the exposure period, but the release rate declined approximately 20 h after patch placement. The median fetal/maternal plasma concentration ratio was 13 - 27 % throughout the exposure period at baseline. A ratio over 100 % was observed for four sheep on the sixth exposure day (102 - 269 %). A minor increase was seen in the median fetal/maternal-ratios during maternal hypoxia. Norbuprenorphine was undetected in all plasma samples.

CONCLUSIONS

The low transplacental passage of less than one fourth of the ewe's exposure supports buprenorphine as an alternative to methadone in opioid maintenance therapy during pregnancy.

Opioid use during pregnancy can impair maternal behavior and the Maternal Brain Network: A literature review

Opioid Use Disorder (OUD) is a global epidemic also affecting women of reproductive age. A standard form of pharmacological treatment for OUD is Opioid Maintenance Therapy (OMT) and buprenorphine has emerged as the preferred treatment for pregnant women with OUD relative to methadone. However, the consequences of BUP exposure on the developing Maternal Brain Network and mother-infant dyad are not well understood. The maternal-infant bond is dependent on the Maternal Brain Network, which is responsible for the dynamic transition from a "nulliparous brain" to a "maternal brain". The Maternal Brain Network consists of regions implicated in maternal care (e.g., medial preoptic area, nucleus accumbens, ventral pallidum, ventral tegmentum area) and maternal defense (e.g., periaqueductal gray). The endogenous opioid system modulates many of the neurochemical changes in these areas during the transition to motherhood. Thus, it is not surprising that exogenous opioid exposure during pregnancy can be disruptive to the Maternal Brain Network. Though less drastic than misused opioids, OMTs may not be without risk of disrupting the neural and molecular structures of the Maternal Brain Network. This review describes the Maternal Brain Network as a framework for understanding how pharmacological differences in exogenous opioid exposure can disrupt the onset and maintenance of the maternal brain and summarizes opioid and OMT (in particular buprenorphine) use in the context of pregnancy and maternal behavior. This review also highlights future directions for evaluating exogenous opioid effects on the Maternal Brain Network in the hopes of raising awareness for the impact of the opioid crisis not only on exposed infants, but also on mothers and subsequent mother-infant bonds.

The Effects of opioids on female fertility, pregnancy and the breastfeeding mother-infant dyad: A Review

Opioids cover a broad class of natural, synthetic and semi-synthetic drugs that act on opioid receptors to produce powerful analgesic effects. Rates of opioid use and opioid agonist maintenance treatment have increased substantially in recent years, particularly among women. Trends and outcomes of opioids use on fertility, pregnancy and breastfeeding, and longer-term child developmental outcomes have not been well-described. Here, we review the existing literature on the health effects of opioid use on female fertility, pregnancy, breastmilk and the exposed infant. We find that the current literature is primarily concentrated on the impact of opioid use in pregnancy and neonatal outcomes, with little exploration of effects on fertility. Studies are limited in number, some with small sample sizes, and many are hampered by methodological challenges related to confounding and other potential biases. Opioid use is becoming more prevalent due to environmental pressures such as COVID-19. More research is needed to better elucidate its effects on reproductive health among younger women and support the development of evidence-based recommendations for safe prescription practices and public health messaging.

Study design and rationale for a randomized controlled trial to assess effectiveness of stochastic vibrotactile mattress stimulation versus standard non-oscillating crib mattress for treating hospitalized opioid-exposed newborns

The incidence of Neonatal Abstinence Syndrome (NAS) continues to rise and there remains a critical need to develop non-pharmacological interventions for managing opioid withdrawal in newborns. Objective physiologic markers of opioid withdrawal in the newborn remain elusive. Optimal treatment strategies for improving short-term clinical outcomes and promoting healthy neurobehavioral development have yet to be defined. This dual-site randomized controlled trial (NCT02801331) is designed to evaluate the therapeutic efficacy of stochastic vibrotactile stimulation (SVS) for reducing withdrawal symptoms, pharmacological treatment, and length of hospitalization, and for improving developmental outcomes in opioid-exposed neonates. Hospitalized newborns (n = 230) receiving standard clinical care for prenatal opioid exposure will be randomly assigned within 48-hours of birth to a crib with either: 1) Intervention (SVS) mattress: specially-constructed SVS crib mattress that delivers gentle vibrations (30-60 Hz, ~12 μm RMS surface displacement) at 3-hr intervals; or 2) Control mattress (treatment as usual; TAU): non-oscillating hospital-crib mattress. Infants will be studied throughout their hospitalization and post discharge to 14-months of age. The study will compare clinical measures (i.e., withdrawal scores, cumulative dose and duration of medications, velocity of weight gain) and characteristic progression of physiologic activity (i.e., limb movement, cardio-respiratory, temperature, blood-oxygenation) throughout hospitalization between opioid-exposed infants who receive SVS and those who receive TAU. Developmental outcomes (i.e., physical, social, emotional and cognitive) within the first year of life will be evaluated between the two study groups. Findings from this randomized controlled trial will determine whether SVS reduces in-hospital severity of NAS, improves physiologic function, and promotes healthy development.

Proxy Finnegan Component Scores for Eat, Sleep, Console in a Cohort of Opioid-Exposed Neonates

OBJECTIVES

The Finnegan Neonatal Abstinence Score (FNAS) monitors infants with neonatal abstinence syndrome (NAS), but it has been criticized for being time consuming and subjective. Many institutions have transitioned to a more straightforward screening tool, Eat, Sleep, Console (ESC), an assessment based on 3 simple observations with a focus on maximizing nonpharmacologic therapies. We aimed to compare the sensitivity and specificity of the ESC with that of the FNAS to determine if infants who needed pharmacologic therapy could potentially be missed when assessed by using ESC.

METHODS

A retrospective cohort study of infants identified by International Classification of Diseases, Ninth Revision and International Classification of Diseases, 10th Revision billing codes for NAS. FNAS scores were recorded every 4 hours for the entire hospitalization. ESC proxy scores were created by using components of the FNAS that referenced eating, sleeping, and consoling. Detailed demographic and clinical data were manually extracted regarding opioid exposures and pharmacologic treatment of NAS.

RESULTS

From 2013 to 2016, 423 infants ≥37 weeks' gestation had a total of 33 115 FNAS scores over 921 days of observation. In total, 287 (68%) were exposed to buprenorphine, 100 (23.7%) were exposed to methadone, and 165 (39%) were pharmacologically treated. The FNAS was 94.8% sensitive and 63.5% specific for pharmacologic treatment, and the ESC proxy variables were 99.4% sensitive and 40.2% specific (P < .01).

CONCLUSIONS

ESC proxy variables have slightly higher sensitivity compared with FNAS, suggesting that ESC use is unlikely to miss infants requiring treatment who would have been identified by FNAS. Transitioning from FNAS to ESC is not likely to impair the care of infants with NAS.

Maintenance agonist treatments for opiate-dependent pregnant women

BACKGROUND

The prevalence of opiate use among pregnant women can range from 1% to 2% to as high as 21%. Just in the United States alone, among pregnant women with hospital delivery, a fourfold increase in opioid use is reported from 1999 to 2014 (Haight 2018). Heroin crosses the placenta, and pregnant, opiate-dependent women experience a six-fold increase in maternal obstetric complications such as low birth weight, toxaemia, third trimester bleeding, malpresentation, puerperal morbidity, fetal distress and meconium aspiration. Neonatal complications include narcotic withdrawal, postnatal growth deficiency, microcephaly, neuro-behavioural problems, increased neonatal mortality and a 74-fold increase in sudden infant death syndrome. This is an updated version of the original Cochrane Review first published in 2008 and last updated in 2013.

OBJECTIVES

To assess the effectiveness of any maintenance treatment alone or in combination with a psychosocial intervention compared to no intervention, other pharmacological intervention or psychosocial interventions alone for child health status, neonatal mortality, retaining pregnant women in treatment, and reducing the use of substances.

SEARCH METHODS

We updated our searches of the following databases to February 2020: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and Web of Science. We also searched two trials registers and checked the reference lists of included studies for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

Randomised controlled trials which assessed the efficacy of any pharmacological maintenance treatment for opiate-dependent pregnant women.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We found four trials with 271 pregnant women. Three compared methadone with buprenorphine and one methadone with oral slow-release morphine. Three out of four studies had adequate allocation concealment and were double-blind. The major flaw in the included studies was attrition bias: three out of four had a high dropout rate (30% to 40%), and this was unbalanced between groups. Methadone versus buprenorphine: There was probably no evidence of a difference in the dropout rate from treatment (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.37 to 1.20, three studies, 223 participants, moderate-quality evidence). There may be no evidence of a difference in the use of primary substances between methadone and buprenorphine (RR 1.81, 95% CI 0.70 to 4.68, two studies, 151 participants, low-quality evidence). Birth weight may be higher in the buprenorphine group in the two trials that reported data MD;-530.00 g, 95%CI -662.78 to -397.22 (one study, 19 particpants) and MD: -215.00 g, 95%CI -238.93 to -191.07 (one study, 131 participants) although the results could not be pooled due to very high heterogeneity (very low-quality of evidence). The third study reported that there was no evidence of a difference. We found there may be no evidence of a difference in the APGAR score (MD: 0.00, 95% CI -0.03 to 0.03, two studies,163 participants, low-quality evidence). Many measures were used in the studies to assess neonatal abstinence syndrome. The number of newborns treated for neonatal abstinence syndrome, which is the most critical outcome, may not differ between groups (RR 1.19, 95% CI 0.87 to1.63, three studies, 166 participants, low-quality evidence). Only one study which compared methadone with buprenorphine reported side effects. We found there may be no evidence of a difference in the number of mothers with serious adverse events (AEs) (RR 1.69, 95% CI 0.75 to 3.83, 175 participants, low-quality evidence) and we found there may be no difference in the numbers of newborns with serious AEs (RR 4.77, 95% CI 0.59, 38.49,131 participants, low-quality evidence). Methadone versus slow-release morphine: There were no dropouts in either treatment group. Oral slow-release morphine may be superior to methadone for abstinence from heroin use during pregnancy (RR 2.40, 95% CI 1.00 to 5.77, one study, 48 participants, low-quality evidence). In the comparison between methadone and slow-release morphine, no side effects were reported for the mother. In contrast, one child in the methadone group had central apnoea, and one child in the morphine group had obstructive apnoea (low-quality evidence).

AUTHORS' CONCLUSIONS

Methadone and buprenorphine may be similar in efficacy and safety for the treatment of opioid-dependent pregnant women and their babies. There is not enough evidence to make conclusions for the comparison between methadone and slow-release morphine. Overall, the body of evidence is too small to make firm conclusions about the equivalence of the treatments compared. There is still a need for randomised controlled trials of adequate sample size comparing different maintenance treatments.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Neurobehavior of newborn infants exposed prenatally to methadone and identification of a neurobehavioral profile linked to poorer neurodevelopmental outcomes at age 24 months

The abuse of prescription opioids and heroin by women of childbearing age over the past decade has resulted in a five-fold increase in the number of infants born opioid-dependent. Daily opioid substitution treatment with methadone is associated with less maternal illicit opioid use and improved antenatal care. However, research on the neurobehavioral effects of daily prenatal exposure to methadone on the infant is limited. Using the NICU Network Neurobehavioral Scale (NNNS), we compared the neurobehavior at birth of 86 infants born to opioid-dependent mothers receiving methadone treatment (MMT) with 103 infants unexposed to methadone. Generalized linear models, adjusted for covariates, showed methadone exposed infants had significantly poorer attention, regulation, and quality of movement. They were also significantly more excitable, more easily aroused, exhibited more non-optimal reflexes, hypertonicity, and total signs of stress abstinence. Maternal MMT was also associated with more indices of neonatal abstinence, including: CNS, visual, genitourinary (GI), and state. Latent profile analysis of the NNNS summary scores revealed four distinct neurobehavioral profiles with infants characterized by the most disturbed neurobehavior at birth having the poorest clinical outcomes at birth, and poorer cognitive and motor development at 24 months of age.

Association of Maternal Opioid Use in Pregnancy With Adverse Perinatal Outcomes in Ontario, Canada, From 2012 to 2018

IMPORTANCE

A recent epidemic of opioid abuse has been described in many communities, although population-based data on trends in use in pregnancy and perinatal outcomes after in utero exposure remain limited.

OBJECTIVE

To assess trends in prenatal opioid use and the potential association between prenatal opioid use and preterm birth and adverse perinatal outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study covered live births and stillbirths among adolescents and women 15 years and older from April 1, 2012, to March 31, 2018, in Ontario, Canada. Data were analyzed from July 29 to October 15, 2019.

EXPOSURES

Any opioid use in pregnancy, ascertained through self-reporting and routine prenatal care.

MAIN OUTCOME AND MEASURES

The primary outcome was preterm birth before a gestational age of 37 weeks. Separate indicators for birth occurring at gestational ages of 34 to 36 weeks (plus 6 to 7 days; late preterm), 32 to 33 weeks (plus 6 to 7 days), 28 to 31 weeks (plus 6 to 7 days), and less than 28 weeks (very preterm birth). Secondary outcomes included small for gestational age, stillbirth, transfer to neonatal intensive care, and 5-minute Apgar score. Coarsened exact matching techniques and Poisson regression models were used to estimate the risk difference and relative risk (RR) of outcomes associated with cannabis exposure to control for confounding.

RESULTS

Among 710 911 women included in the analytic sample (mean [SD] age, 30.4 [5.3] years), 8059 used opioids (1.1%), with prevalence decreasing from 1.31% (95% CI, 1.25%-1.38%) in fiscal year 2012-2013 to 1.05% (95% CI, 0.99%-1.11%) in fiscal year 2017-2018 (P < .001 for trend). Use was highest among women in the lowest quintile of area-level income (2.36% vs 0.56% in the highest quintile; RR, 3.86; 95% CI, 3.58-4.15) and did not decrease over time in this group (from 2.63% [95% CI, 2.41%-2.87%] in 2012-2013 to 2.35% [95% CI, 2.14%-2.58%] in 2017-2018; P = .23 for trend). The crude rate of preterm birth at a gestational age of less than 37 weeks was 14.0% (n = 1127) among women with reported use in pregnancy and 6.0% (n = 42 226) among women who did not use opioids in the unmatched cohort. The adjusted RR for preterm birth before a gestational age of 37 weeks was 1.63 (95% CI, 1.52-1.75) among opioid users compared with nonusers and 1.77 (95% CI, 1.35-2.31) for preterm birth before 32 weeks. Among newborns, risk for neonatal intensive care was 40.5% with perinatal exposure to opioids compared with 13.9% in unexposed infants (RR, 2.91; 95% CI, 2.80-3.03).

CONCLUSIONS AND RELEVANCE

Rates of opioid use in pregnancy have declined in recent years, although use remains significantly higher among lower-income women. In this large population-based cohort, opioid use in pregnancy was associated with an increased risk of preterm birth and admission to a neonatal intensive care unit.

Development of an abbreviated symptom score for the neonatal abstinence syndrome

OBJECTIVE

We sought a shortened MOTHER neonatal abstinence syndrome (NAS) and Finnegan score that would retain comparable performance characteristics of the full instrument.

STUDY DESIGN

Retrospective cohort.

RESULTS

In total, 124,170 MOTHER NAS scores between August 2007 and May 2016 from 775 infants (≥36 weeks) were examined. Classification and regression tree model identified the most important subsets of the scored variables. A 9-element shortened scale yielded >90% sensitivity and specificity to predict clinical endpoints based on the full 19-element MOTHER NAS score. Conversion of the data sets to the Finnegan score, and applying the same procedure resulted in a nine-element score with similar performance characteristics.

CONCLUSION

Shortened scoring instruments were identified with the high-predictive power for clinical endpoints based on the 19-element full MOTHER NAS score. There was no substantial variation in performance for age, supporting the current practice of utilizing a single scoring tool regardless of postnatal age.

Buprenorphine pharmacotherapy for the management of neonatal abstinence syndrome in methadone‐exposed neonates

We aimed to compare the outcomes of pharmacotherapy with either buprenorphine or methadone in infants treated for neonatal abstinence syndrome (NAS) secondary to intrauterine exposure to methadone. This is a multi‐center, retrospective cohort study to assess length of treatment (LOT), hospital length of stay (LOS), and cumulative opioid exposure between infants treated with either methadone or buprenorphine for NAS secondary to in utero exposure to methadone. Infants delivered at a gestational age ≥35 weeks and a maternal history of opioid‐use disorder and/or urine drug screen positive for methadone, and postnatal pharmacotherapy for NAS with either buprenorphine or methadone as first‐line opioid replacement therapy, were eligible. Median LOT, LOS, and cumulative opioid exposure were compared between buprenorphine‐ and methadone‐treated infants. A total of 156 infants (48 treated with buprenorphine and 108 with methadone) were identified. The median LOT and LOS for buprenorphine‐treated infants was 8 and 13 days compared with 15 and 20 days for methadone‐treated infants, respectively, P < .001 for both outcomes. Median cumulative opioid dose in morphine equivalents was 0.6 mg/kg for buprenorphine‐treated infants vs 1.05 mg/kg for methadone‐treated infants, P < .001. No adverse effects were noted among either group. Of infants treated with buprenorphine, 34 (71%) required the addition of adjunctive pharmacotherapy during the NICU stay, compared with 31 (32%) in the methadone‐treated group, P = .0008. However, significantly fewer infants treated with buprenorphine required continuation of therapy beyond discharge as compared with those treated with methadone. The difference is most likely a reflection of the protocols used by the sites. In infants that required pharmacotherapy for NAS secondary to intrauterine exposure to methadone, treatment with buprenorphine, compared with methadone therapy, was associated with better outcomes. If confirmed with prospective data, buprenorphine could be considered first‐line therapy for the two medication‐assisted treatment regimens recommended by the American College of Obstetricians and Gynecologists.

Risk Factors Associated with the Occurrence of Neonatal Opioid Withdrawal Syndrome: A Review

In a number of countries, the prevalence of neonatal opioid withdrawal syndrome (NOWS) is increasing. While NOWS is ultimately the result of opioid exposure in utero, a wide range of risk factors have been associated with the prevalence of NOWS, extending beyond just drug exposure. This article reviews the available literature on factors associated with the incidence of NOWS in opioid-exposed neonates. A range of risk factors have been associated with NOWS, including features of neonatal drug exposure, maternal and neonatal characteristics, aspects of labor and delivery, and genetics. Increased length of gestation and higher birth weight were consistently associated with an increased risk of NOWS, while breast feeding and 'rooming-in' were associated with a reduced risk of NOWS. Additionally, several genetic factors have also been associated with NOWS severity. There is conflicting evidence on the association between NOWS and other risk factors including opioid dose, neonate sex, and the use of some medications during pregnancy. This may be in part attributable to differences in how NOWS is diagnosed and the variety of methodologies across studies. While a large number of risk factors associated with NOWS are non-modifiable, encouraging pregnant women to reduce other drug use (including smoking), breast feed their child, and the judicious use of medications during pregnancy may help reduce the prevalence of NOWS. The presence or absence of NOWS in an opioid-exposed neonate is associated with a wide range of factors. Some of these modifiable risk factors may be potential targets for the primary prevention of NOWS.

Early postpartum resting-state functional connectivity for mothers receiving buprenorphine treatment for opioid use disorder: A pilot study

Between 1999 and 2014, the prevalence of opioid use disorder (OUD) among pregnant women quadrupled in the USA. The standard treatment for peripartum women with OUD is buprenorphine. However, the maternal behavior neurocircuit that regulates maternal behavior and mother-infant bonding has not been previously studied for human mothers receiving buprenorphine treatment for OUD (BT). Rodent research shows opioid effects on reciprocal inhibition between maternal care and defence maternal brain subsystems: the hypothalamus and periaqueductal gray, respectively. We conducted a longitudinal functional magnetic resonance imaging (fMRI) pilot study in humans to specifically examine resting-state functional connectivity (rs-FC) between the periaqueductal gray and hypothalamus, as well as to explore associations with maternal bonding for BT. We studied 32 mothers who completed fMRI scans at 1 month (T1) and 4 months postpartum (T2), including seven mothers receiving buprenorphine for OUD and 25 non-OUD mothers as a comparison group (CG). The participants underwent a 6-minute resting-state fMRI scan at each time point. We measured potential bonding impairments using the Postpartum Bonding Questionnaire to explore how rs-FC with periaqueductal gray is associated with bonding impairments. Compared to CG, BT mothers differed in periaqueductal gray-dependent rs-FC with the hypothalamus, amygdala, insular cortex and other brain regions at T1, with many of these differences disappearing at T2, suggesting potential therapeutic effects of continuing buprenorphine treatment. In contrast, the "rejection and pathological anger" subscale of the Postpartum Bonding Questionnaire at T1 and T2 was associated with the T1-to-T2 increases in periaqueductal gray-dependent rs-FC with the hypothalamus and amygdala. Preliminary evidence links maternal bonding problems for mothers with OUD early in the postpartum to connectivity between specific care and defence maternal brain circuits, which may be mitigated by buprenorphine treatment. This exploratory study supports a potential mechanism for investigating both the therapeutic benefits and risks of opioids for maternal care and bonding with infants.

Effects of opioids on the parental brain in health and disease

The epidemic of opioid use disorder (OUD) directly affects millions of women of child-bearing age. Unfortunately, parenting behaviors - among the most important processes for human survival - are vulnerable to the effects of OUD. The standard of care for pregnant women with OUD is opioid maintenance therapy (OMT), of which the primary objective is to mitigate addiction-related stress. The aim of this review is to synthesize current information specific to pregnancy and parenting that may be affected by OUD. We first summarize a model of the parental brain supported by animal research and human neuroimaging. We then review animal models of exogenous opioid effects on parental brain and behavior. We also present preliminary data for a unifying hypothesis that may link different effects of exogenous opioids on parenting across species and in the context of OMT. Finally, we discuss future directions that may inform research and clinical decision making for peripartum women with OUD.

Models of care for neonatal abstinence syndrome: What works?

Opioid use disorders and the prescription of long-acting medications for their treatment have increased dramatically over the last decade among pregnant women. Newborns who experience prolonged in utero opioid exposure may develop neonatal abstinence syndrome (NAS). Until recently, much of the focus on improving care for NAS has been on pharmacologically-based care models. Recent studies have illustrated the benefits of rooming-in and parental presence on NAS outcomes. Single center Quality Improvement (QI) initiatives demonstrate the benefits of non-pharmacologic care bundles and symptom prioritization in decreasing the proportion of infants pharmacologically treated and length of hospital stay. Little remains known about the impact of these varied cared models on maternal-infant attachment and mental health. In this review article, we will propose an optimal model of care to improve short- and long-term outcomes for newborns, their mothers and families, and perinatal care systems.

Assessment of the newborn prenatally exposed to drugs: The history

This paper reviews the history of the development of scoring tools used to assess the occurrence and severity of the Neonatal Abstinence Syndrome. Beginning with the first tools published in 1975, this review describes tools published through 2010; identifies each tool's strengths and weaknesses; and discusses their representation in the literature.

Neonatal Abstinence Syndrome: An Uncontrollable Epidemic

There is an uncontrollable epidemic of drug abuse, with the misuse of opioids the most alarming. Along with the increase in opioid abuse, there exists a concomitant upsurge in the number of neonates experiencing neonatal abstinence syndrome (NAS) due to the effects of the mother's withdrawal from the drug. Neonates experiencing NAS exhibit various nervous system, gastrointestinal, and respiratory untoward symptoms. Diagnosis is determined by taking an accurate maternal history and assessment of clinical signs and symptoms. Clinical management strategies include pharmacologic and nonpharmacologic therapies. Nursing care is evidence based, includes nonpharmacologic therapies, and focuses on prevention and support.

Early life opioid exposure and potential long-term effects

The long-term consequences of perinatal opioid exposure and subsequent development of neonatal opioid withdrawal syndrome is largely unknown and likely dependent on a multitude of factors, including co-morbid drug use, pre- and post-natal care, and individual factors including the maternal-infant relationship and home environment. This review summarizes the current literature from clinical and preclinical studies on perinatal opioid exposure, focusing on the consequences in the offspring. Although a large number of preclinical studies have been conducted examining the impact of prenatal opioid exposure, the models employed are not necessarily representative of clinical use patterns, making it challenging to translate these results to the impacted population. Use of more clinically-relevant models of perinatal opioid exposure are requisite for the development of improved pharmacological and behavioral treatment strategies to improve quality of life for this vulnerable population.

EEG Findings in Infants With Neonatal Abstinence Syndrome Presenting With Clinical Seizures

Neonatal abstinence syndrome (NAS) refers to a constellation of signs occurring in newborn infants who were exposed to opioids or opiates in utero. These manifestations include poor feeding, gastrointestinal disorders, abnormal sleep patterns, and neurological signs such as jitteriness, tremors, and seizures (1, 2). Myoclonus, jitteriness, and tremors often may be interpreted as seizures and therefore treated as epileptic seizures. Objective: To determine whether seizure like activity observed in infants with NAS correlate with electroencephalogram (EEG) findings. Design/ Method: We reviewed the standard EEG or video electroencephalogram (VEEG) of infants with NAS who were admitted because of seizure-like clinical activity. The exclusion criteria were major neurological anomalies, hypoxic ischemic encephalopathy, metabolic disorders, or with clinical diagnosis other than NAS. Results: Forty neonates met study criteria; 28 had standard EEG recordings and 18 had VEEG. Mean gestational age was 38.5 weeks. The onset of seizure-like clinical activity was as early as day 1 and as late as day 16 of life. The clinical seizure-like activity described at the referring hospital were jerking, rhythmic movement of the extremities, or tremors. Only three (7.5%) neonates had epileptic seizures. There were increased sharp transients in frontal, central, temporal, and or occipital regions. VEEG showed disturbed non-rapid eye movement (REM) sleep with frequent arousal, jittery movements, or sleep myoclonus. Conclusion: Clinical seizure-like activity correlates poorly with epileptic seizures in infants with NAS. In neonates with NAS, a VEEG would be useful to determine if the clinical seizure-like activity is of epileptic origin or not, prior to initiation of anti-seizure medications.

Neonatal abstinence syndrome

Neonatal abstinence syndrome refers to the signs and symptoms attributed to the cessation of prenatal exposure (via placental transfer) to various substances. This Primer focuses on neonatal abstinence syndrome caused by opioid use during pregnancy - neonatal opioid withdrawal syndrome (NOWS). As the global prevalence of opioid use has alarmingly increased, so has the incidence of NOWS. NOWS can manifest with varying severity or not at all, for unknown reasons, but is likely to be associated with multiple factors, both maternal (for example, smoking and additional substance exposures) and neonatal (gestational age, sex and genetics). Care for the infant with NOWS begins with addressing the issues experienced by pregnant women with opioid use disorder. Co-occurring mental illness, economic hardship, intimate partner violence, infectious diseases and limited access to care are common in these women and can result in poor maternal and neonatal outcomes. Although there is no consensus regarding optimal NOWS management, non-pharmacological interventions (such as breastfeeding and rooming-in of the mother and the baby) have become a priority, as they can ameliorate symptoms without the need for further opioid exposure. Untreated NOWS can be associated with morbidity in early infancy, and the long-term consequences of fetal opioid exposure are only beginning to be understood.

Differences in hospital length of stay between neonates exposed to buprenorphine versus methadone in utero: A retrospective chart review

Introduction

Neonatal abstinence syndrome is a growing concern in neonatal intensive care units in rural and remote settings.

Methods

A retrospective chart review was conducted of 180 mother-infant dyads born with in utero exposure to buprenorphine (n=60), methadone (n=60) or to other opioids (n=60) to determine neonatal length of stay in hospital, number of days on morphine, day of life of initiation of morphine and the need for phenobarbital.

Results

The length of stay in hospital for neonates was 5.8 days shorter (95% confidence interval [CI] 6.1 to 8.5 days) for buprenorphine exposure in utero compared to methadone (P=0.001). For neonates requiring treatment for Neonatal abstinence syndrome, those with in utero exposure to buprenorphine required 6.1 fewer days (95% CI 2.5 to 9.7) of treatment with morphine then those exposed to methadone (P<0.0005). There were no statistically significant differences in day of life of initiation of morphine therapy for each of the study groups. The proportion of neonates requiring adjuvant therapy with phenobarbital was statistically significantly higher in neonates exposed to methadone in utero than either buprenorphine or illicit opioids (P<0.0005).

Conclusions

Retrospective data suggest that neonates with in utero exposure to buprenorphine experience a shorter length of stay in hospital, fewer days of treatment with morphine for neonatal abstinence syndrome, and less use of phenobarbital than neonates exposed in utero to methadone. This suggests that Ontario provincial guidelines should be updated to recommend buprenorphine as first line for replacement therapy in pregnancy.

Treating Women Who Are Pregnant and Parenting for Opioid Use Disorder and the Concurrent Care of Their Infants and Children: Literature Review to Support National Guidance

OBJECTIVES

The prevalence of opioid use disorder (OUD) during pregnancy is increasing. Practical recommendations will help providers treat pregnant women with OUD and reduce potentially negative health consequences for mother, fetus, and child. This article summarizes the literature review conducted using the RAND/University of California, Los Angeles Appropriateness Method project completed by the US Department of Health and Human Services Substance Abuse and Mental Health Services Administration to obtain current evidence on treatment approaches for pregnant and parenting women with OUD and their infants and children.

METHODS

Three separate search methods were employed to identify peer-reviewed journal articles providing evidence on treatment methods for women with OUD who are pregnant or parenting, and for their children. Identified articles were reviewed for inclusion per study guidelines and relevant information was abstracted and summarized.

RESULTS

Of the 1697 articles identified, 75 were included in the literature review. The perinatal use of medication for addiction treatment (MAT, also known as medication-assisted treatment), either methadone or buprenorphine, within comprehensive treatment is the most accepted clinical practice, as withdrawal or detoxification risks relapse and treatment dropout. Medication increases may be needed with advancing pregnancy, and are not associated with more severe neonatal abstinence syndrome (NAS). Switching medication prenatally is usually not recommended as it can destabilize opioid abstinence. Postnatally, breastfeeding is seen as beneficial for the infant for women who are maintained on a stable dose of opioid agonist medication. Less is known about ideal pain management and postpartum dosing regimens. NAS appears generally less severe following prenatal exposure to buprenorphine versus methadone. Frontline NAS medication treatments include protocol-driven methadone and morphine dosing in the context of nonpharmacological supports.

CONCLUSIONS

Women with OUD can be treated with methadone or buprenorphine during pregnancy. NAS is an expected and manageable condition. Although research has substantially advanced, opportunities to guide future research to improve maternal and infant outcomes are provided.

Management of eight labor and delivery patients dependent on buprenorphine (Subutex™): A retrospective chart review

Background: Opioid use during pregnancy is a growing concern in the United States. Buprenorphine has been recommended by “The American College of Obstetrics and Gynecology” as an alternative to methadone to decrease risks associated with the use of illicit opioids during pregnancy. The partial μ-opioid agonists’ unique pharmacology, including its long half time and high affinity to the μ-opioid receptor, complicates patient management in a highly kinetic, and often urgent field like obstetric anesthesia. We reviewed our management and outcomes in this medically complex population.

Methods: An Institutional Review Board (IRB) approved retrospective chart review was conducted of women admitted to the University of Washington Medical Center Labor and Delivery unit from July 2012 to November 2013 using buprenorphine. All deliveries, including intrauterine fetal demise, were included.

Results: Eight women were admitted during this period to our L&D floor on buprenorphine. All required peri-partum anesthetic management either for labor and/or cesarean delivery management. Analgesic management included dilaudid or fentanyl PCA and/or continued epidural infusion, and in one instance ketamine infusion, while the pre-admission buprenorphine regimen was continued. Five babies were viable, two women experienced intrauterine fetal death at 22 and 36 weeks gestational age (GSA), respectively, and one neonate died shortly after delivery due to a congenital diaphragmatic hernia.

Conclusions: This case series illuminates the medical complexity of parturients using buprenorphine. Different treatment modalities in the absence of evidence-based guidelines included additional opioid administration and continued epidural analgesia. The management of post-cesarean pain in patients on partial μ-opioid agonists remains complex and variable, and evidence-based guidelines could be useful for clinicians to direct care.

Management of eight labor and delivery patients dependent on buprenorphine (Subutex™): A retrospective chart review

Background: Opioid use during pregnancy is a growing concern in the United States. Buprenorphine has been recommended by "The American College of Obstetrics and Gynecology" as an alternative to methadone to decrease risks associated with the use of illicit opioids during pregnancy. The partial μ-opioid agonists' unique pharmacology, including its long half time and high affinity to the μ-opioid receptor, complicates patient management in a highly kinetic, and often urgent field like obstetric anesthesia. We reviewed our management and outcomes in this medically complex population. Methods: An Institutional Review Board (IRB) approved retrospective chart review was conducted of women admitted to the University of Washington Medical Center Labor and Delivery unit from July 2012 to November 2013 using buprenorphine. All deliveries, including intrauterine fetal demise, were included. Results: Eight women were admitted during this period to our L&D floor on buprenorphine. All required peri-partum anesthetic management either for labor and/or cesarean delivery management. Analgesic management included dilaudid or fentanyl PCA and/or continued epidural infusion, and in one instance ketamine infusion, while the pre-admission buprenorphine regimen was continued. Five babies were viable, two women experienced intrauterine fetal death at 22 and 36 weeks gestational age (GSA), respectively, and one neonate died shortly after delivery due to a congenital diaphragmatic hernia. Conclusions: This case series illuminates the medical complexity of parturients using buprenorphine. Different treatment modalities in the absence of evidence-based guidelines included additional opioid administration and continued epidural analgesia. The management of post-cesarean pain in patients on partial μ-opioid agonists remains complex and variable, and evidence-based guidelines could be useful for clinicians to direct care.

Antenatal methadone vs buprenorphine exposure and length of hospital stay in infants admitted to the intensive care unit with neonatal abstinence syndrome

OBJECTIVE

Antenatal exposure to methadone or buprenorphine often causes neonatal abstinence syndrome (NAS) in newborns. However, comparative effects on affected infants' hospital courses are inconclusive. We sought to estimate the relationship of antenatal exposure with methadone or buprenorphine and infants' length of stay among hospitalized infants with NAS.

STUDY DESIGN

This was a retrospective cohort study of hospitalized infants with NAS with either maternal exposure. Eligible infants were singleton infants born ⩾36 weeks' gestation and diagnosed with NAS<7 days of age between 2011 and 2014 in the Pediatrix Clinical Data Warehouse. Infant with congenital anomalies and those of multiple gestation were excluded.

RESULTS

Of 3364 eligible infants, 2202 (65%) were exposed to methadone and 1162 (34%) to buprenorphine. Infants exposed to buprenorphine had a lower rate of pharmacologic treatment for NAS (88 vs 91%, P<0.001). Median length of hospital stay was shorter among infants exposed to buprenorphine (21 days (inter-quartile range; 13-31) vs methadone (24 days (15-38), P<0.0001)). On multivariable Cox proportional hazard analyses, buprenorphine was associated with a shorter length of stay (hazard ratio (HR)=1.47 (95% confidence interval (CI): 1.32-1.62, P<0.001) after controlling for maternal age, parity, race or ethnicity, prenatal care, smoking status, use of antidepressants, use of benzodiazepines, and infant gestational age, small for gestational age status, cesarean delivery, sex, out born status, type of pharmacotherapy, breast milk use, year and center. We observed similar results in model using infants matched 1:1 with propensity scores for antenatal medication exposure (HR 1.39 for buprenorphine, CI 1.32-1.62, P<0.001).

CONCLUSION

Among infants born ⩾36 weeks' gestation with NAS, antenatal buprenorphine exposure was associated with a decreased length of stay relative to antenatal methadone exposure.

Opioid Use in Pregnancy, Neonatal Abstinence Syndrome, and Childhood Outcomes: Executive Summary of a Joint Workshop by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, American College of Obstetricians and Gynecologists, American Academy of Pediatrics, Society for Maternal-Fetal Medicine, Centers for Disease Control and Prevention, and the March of Dimes Foundation

In April 2016, the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited experts to a workshop to address numerous knowledge gaps and to review the evidence for the screening and management of opioid use in pregnancy and neonatal abstinence syndrome. The rising prevalence of opioid use in pregnancy has led to a concomitant dramatic fivefold increase in neonatal abstinence syndrome over the past decade. Experts from diverse disciplines addressed research gaps in the following areas: 1) optimal screening for opioid use in pregnancy; 2) complications of pregnancy associated with opioid use; 3) appropriate treatments for pregnant women with opioid use disorders; 4) the best approaches for detecting, treating, and managing newborns with neonatal abstinence syndrome; and 5) the long-term effects of prenatal opioid exposure on children. Workshop participants identified key scientific opportunities to advance the understanding of opioid use disorders in pregnancy and to improve outcomes for affected women, their children, and their families. This article provides a summary of the workshop presentations and discussions.

Neonatal Abstinence Syndrome: Presentation and Treatment Considerations

The increase in opioid use among the general population is reflected in pregnant women and neonatal abstinence syndrome (NAS) statistics. This increase has produced an unprecedented focus on NAS from both the political-judicial sphere and the medical community. Under the banner of fetal protection, judges and prosecutors have implemented punitive approaches against women who use prescribed and nonprescribed opioids during pregnancy, including arrest, civil commitment, detention, prosecution, and loss of custody or termination of parental rights. Within the medical community, questions have been raised regarding protocols to detect prenatal drug exposure at delivery, NAS treatment protocols, the need for quality-improvement strategies to standardize care and reduce length of stay for mother and infant, and the benefits of engaging the mother in the care of her infant. It is not uncommon for the expression of strong discordant views on these issues both between and among these political-judicial and medical constituencies. Closely examining the issues often reveal a lack of understanding of substance use disorders, their treatment, and the occurrence and treatment of NAS. This study provides an in-depth examination of NAS, including variations in presentation and factors that impact the efficacy of treatment, and also identifying questions that remain unanswered. Finally, 4 key areas on which future research should focus to guide both medical care and public policy are discussed.

The relationship between gestational age and the severity of neonatal abstinence syndrome

BACKGROUND AND AIMS

The relationship between gestational age at delivery and the severity of neonatal abstinence syndrome (NAS) is poorly understood. Our objective was to compare the length of pharmacotherapy and hospital stay among opioid-exposed infants born during the late pre-term, early term, full term and late term periods.

DESIGN

Retrospective cohort study of infants affected by NAS.

SETTING

MetroHealth Medical Center in Cleveland, OH, USA: an urban tertiary care hospital serving as the referral center for opioid dependency in pregnancy with a level III neonatal intensive care unit.

PARTICIPANTS

All deliveries complicated by maternal opioid exposure from January 2000 to October 2014; 403 were eligible to be included [n = 102 late pre-term, 34-36 weeks (LP), n = 158 early term, 37-38 weeks (ET), n = 122 full term, 39-40 weeks (FT), n = 21 late term, ≥41 weeks (LT)].

MEASUREMENTS

NAS requiring pharmacotherapy with opioids and hospital stay duration were compared between gestational age cohorts. Interaction by type of maternal medication was evaluated.

FINDINGS

The necessity for pharmacotherapy for NAS was similar in all gestational age groups [LP n = 45/102 (44%), ET n = 65/158 (41%), FT n = 55/122 (45%), LT n = 9/21 (43%); P = 0.92]. However, the median duration of pharmacotherapy for NAS was significantly different between the groups [LP =16.0 median (interquartile range: IQR = 10.0-24.0) days, ET = 22.5 (IQR = 15.0-40.0), FT = 23.0 (IQR = 6.0-38.0), LT = 22.0 (IQR = 6.0-28.0); P = 0.02]. Neonatal intensive care unit admission for NAS (P = 0.07) and total length of stay (P = 0.27), which includes observation for NAS not requiring medication, were not different. There was no significant interaction between gestational age cohorts and maternal medication assisted treatment therapy on the need for or duration of NAS treatment. The results were unchanged when evaluated for potential confounding variables.

CONCLUSIONS

Gestational age (pre-term, term or late term) at birth appears to be unrelated to the need for pharmacotherapy to treat neonatal abstinence syndrome (NAS) in late pre-term and term infants. If treatment is needed it may tend to be given for longer in term than pre-term or late term infants.

Judging the Neonatal Abstinence Syndrome Assessment Tools to Guide Future Tool Development: The use of Clinimetrics as Opposed to Psychometrics

In the face of the current Neonatal Abstinence Syndrome (NAS) epidemic, there is considerable variability in the assessment and management of infants with NAS. In this manuscript, we particularly focus on NAS assessment, with special attention given to the popular Finnegan Neonatal Abstinence Score (FNAS). A major instigator of the problem of variable practices is that multiple modified versions of the FNAS exist and continue to be proposed, including shortened versions. Furthermore, the validity of such assessment tools has been questioned, and as a result, the need for better tools has been suggested. The ultimate purpose of this manuscript, therefore, is to increase researchers' and clinicians' understanding on how to judge the usefulness of NAS assessment tools in order to guide future tool development and to reduce variable practices. In short, we suggest that judgment of NAS assessment tools should be made on a clinimetrics viewpoint as opposed to psychometrically. We provide examples, address multiple issues that must be considered, and discuss future tool development. Furthermore, we urge researchers and clinicians to come together, utilizing their knowledge and experience, to assess the utility and practicality of existing assessment tools and to determine if one or more new or modified tools are needed with the goal of increased agreement on the assessment of NAS in practice.

Update on pharmacotherapy for treatment of opioid use disorder

INTRODUCTION

Opioid Use Disorder (OUD) is a significant public health concern, negatively impacting the medical, psychological, and social domains of an individual's life as well as creating substantial burdens for society. Effective treatment interventions are necessary for reduction of OUD and its consequences. Pharmacotherapy represents a central component of management. Areas covered: This review focuses on pharmacologic strategies for OUD treatment, discussing both primary as well as adjunctive therapy modalities. We will discuss both medications used during detoxification to treat withdrawal, as well as those used as maintenance therapy. Detox medications include alpha-2 adrenergic agonists, such as clonidine, as well as the μ-opioid agonist, methadone, and the μ-opioid partial agonist, buprenorphine. Opioid maintenance treatment (OMT) is also discussed, focusing on those medications meant to substitute abused opioids and includes the agonists, methadone and buprenorphine, as well as supervised intravenous heroin, and opioid antagonist, naltrexone. Expert opinion: Medication therapy for treatment of OUD has demonstrated efficacy and is of great clinical benefit. While agonist treatment with methadone or buprenorphine remains the gold standard, there is an important place for use of long-acting antagonist therapy with naltrexone. Continued investigation into treatment paradigms and behavioral platforms which optimize medication therapy is most needed.

Neonatal abstinence syndrome: Historical perspective, current focus, future directions

BACKGROUND

Neonatal abstinence syndrome (NAS) occurs following prenatal opioid exposure. It is characterized by signs and symptoms indicating central nervous system hyperirritability and autonomic nervous system, gastrointestinal tract, and respiratory system dysfunction.

OBJECTIVE

This article: (1) briefly reviews NAS history, including initial identification, assessment, and treatment efforts; (2) summarizes the current status of and current issues surrounding recent NAS assessment and treatment, and (3) details future directions in NAS conceptualization, measurement, and treatment.

RESULTS

Mortality rate estimates in neonates treated for NAS exceeded 33%, and surpassed 90% for un-treated infants during the late-1800s until the mid-1900s. The focus of both assessment and treatment over the past 50years is predominantly due to two forces. First, methadone pharmacotherapy for "heroin addiction" led to women in methadone maintenance programs who were, or became pregnant. The second was defining NAS and developing a measure of neonatal withdrawal, the Neonatal Abstinence Scoring System (NASS). Various NAS treatment protocols were based on the NASS as well as other NAS measures.

CONCLUSIONS

Future research must focus on psychometrically sound screening and assessment measures of neonatal opioid withdrawal for premature, term and older infants, measuring and treating possible withdrawal from non-opioids, particularly benzodiazepines, integrated non-pharmacological treatment of NAS, weight-based versus symptom-based treatment of NAS, and second-line treatment for NAS.

Medication-assisted treatment of opioid use disorder: review of the evidence and future directions

Medication-assisted treatment of opioid use disorder with physiological dependence at least doubles rates of opioid-abstinence outcomes in randomized, controlled trials comparing psychosocial treatment of opioid use disorder with medication versus with placebo or no medication. This article reviews the current evidence for medication-assisted treatment of opioid use disorder and also presents clinical practice imperatives for preventing opioid overdose and the transmission of infectious disease. The evidence strongly supports the use of agonist therapies to reduce opioid use and to retain patients in treatment, with methadone maintenance remaining the gold standard of care. Combined buprenorphine/naloxone, however, also demonstrates significant efficacy and favorable safety and tolerability in multiple populations, including youth and prescription opioid-dependent individuals, as does buprenorphine monotherapy in pregnant women. The evidence for antagonist therapies is weak. Oral naltrexone demonstrates poor adherence and increased mortality rates, although the early evidence looks more favorable for extended-release naltrexone, which has the advantages that it is not subject to misuse or diversion and that it does not present a risk of overdose on its own. Two perspectives-individualized treatment and population management-are presented for selecting among the three available Food and Drug Administration-approved maintenance therapies for opioid use disorder. The currently unmet challenges in treating opioid use disorder are discussed, as are the directions for future research.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.