Factors associated with buprenorphine versus methadone use in 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.

Brain circuits for maternal sensitivity and pain involving anterior cingulate cortex among mothers receiving buprenorphine treatment for opioid use disorder

Opioid-induced deficits in maternal behaviors are well-characterized in rodent models. Amid the current epidemic of opioid use disorder (OUD), prevalence among pregnant women has risen sharply. Yet, the roles of buprenorphine replacement treatment for OUD (BT/OUD) in the brain functions of postpartum mothers are unclear. Using functional magnetic resonance imaging (fMRI), we have developed an evolutionarily conserved maternal behavior neurocircuit (MBN) model to study human maternal care versus defensive/aggressive behaviors critical to mother-child bonding. The anterior cingulate gyrus (ACC) is not only involved in the MBN for mother-child bonding and attachment, but also part of an opioid sensitive "pain-matrix". The literature suggests that prescription opioids produce physical and emotional "analgesic" effects by disrupting specific resting-state functional connectivity (rs-FC) of ACC to regions related to MBN. Thus, in this longitudinal study, we report findings of overlapping MBN and pain matrix circuits, for mothers with chronic exposure of BT/OUD. A total of 32 mothers were studied with 6 min rs-FC at 1 month (T1) and 4 months postpartum (T2), including seven on BT/OUD and 25 non-BT/OUD mothers as a comparison group. We analyzed rs-FC between the insula, putamen, and the dorsal anterior cingulate cortex (DACC) and rostral ACC (RACC), as the regions of interest that mediate opioid analgesia. BT/OUD mothers, as compared to non-BT/OUD mothers, showed less left insula-RACC rs-FC but greater right putamen-DACC rs-FC at T1, with these between-group differences diminished at T2. Some of these rs-FC results were correlated with the scores of postpartum parental bonding questionnaire. We found time-by-treatment interaction effects on DACC and RACC-dependent rs-FC, potentially identifying brain mechanisms for beneficial effects of BT, normalizing dysfunction of maternal brain and behavior over the first four months postpartum. This study complements recent studies to ascertain how BT/OUD affects maternal behaviors, mother-child bonding, and intersubjectivity and reveals potential MBN/pain-matrix targets for novel interventions.

Access to Medications for Opioid Use Disorder and Associated Factors Among Adolescents and Young Adults: A Systematic Review

IMPORTANCE

The ongoing overdose crisis continues to adversely affect adolescents and young adults (AYAs) and has led to numerous preventable deaths. Medications for opioid use disorder (MOUD), such as methadone, buprenorphine, and naltrexone, have the potential to reduce opioid use and associated harms; however, there are concerns that AYAs lack access to these potentially life-saving medications.

OBJECTIVE

To systematically review peer-reviewed literature on MOUD access and associated factors to synthesize strategies that can improve MOUD access for AYAs who use opioids.

EVIDENCE REVIEW

The MEDLINE, Embase, PsycINFO, CINAHL, Sociological Abstracts, Web of Science, and Global Dissertations & Theses databases were searched from database inception until May 3, 2021. English, French, Russian, or Spanish peer-reviewed studies that evaluated the availability, prescription receipt, or initiation of MOUD were eligible for inclusion.

FINDINGS

This systematic review identified 37 cohort (n = 17), cross-sectional (n = 15), and qualitative (n = 5) studies that accounted for 179 785 AYAs (mean [SD] age, 24.4 [3.9] years; 148 779 [85%] were female; 67 771 [84%] were White) and examined access to methadone (30 studies), buprenorphine (26 studies), and naltrexone (10 studies). Findings reinforce concerns that AYAs were less likely to access MOUD and suggest that adolescents were more likely to receive naltrexone or buprenorphine-naloxone, which have a lower potential for abuse, in comparison with young adults. This review also identified other factors that were associated with MOUD access, including criminal justice involvement, residing in the US South, living in a limited-income area, Black race, and Hispanic or Latino ethnicity, suggesting ways in which treatment services may be improved to increase MOUD access and meet the treatment goals of AYAs.

CONCLUSION AND RELEVANCE

This systematic review found gaps in MOUD access between AYAs and non-AYA populations in addition to differences in MOUD access between adolescents and young adults. Considering that existing clinical guidelines recommend the use of MOUD among AYAs, and in light of the increasing number of opioid toxicity deaths, there is a need to improve MOUD access among AYAs by reducing barriers to MOUD and providing AYAs with a continuum of health and social supports alongside MOUD. Future research into ways to encourage MOUD uptake among AYAs may improve the treatment and health outcomes for this population.

Reduced Child-Oriented Face Mirroring Brain Responses in Mothers With Opioid Use Disorder: An Exploratory Study

While the prevalence of opioid use disorder (OUD) among pregnant women has multiplied in the United States in the last decade, buprenorphine treatment (BT) for peripartum women with OUD has been administered to reduce risks of repeated cycles of craving and withdrawal. However, the maternal behavior and bonding in mothers with OUD may be altered as the underlying maternal behavior neurocircuit (MBN) is opioid sensitive. In the regulation of rodent maternal behaviors such as licking and grooming, a series of opioid-sensitive brain regions are functionally connected, including the ventral pallidum (VP). In humans, these brain regions, interact with the supplementary motor area (SMA) to regulate maternal behaviors and are functionally dysregulated by opioids. It is unclear how these brain regions respond to the emotions of their child for mothers receiving BT. In this functional magnetic resonance imaging (fMRI) pilot study in 22 mothers within the first postpartum year, including six mothers receiving BT and 16 non-OUD mothers as a comparison group (CG), we devised a child face mirroring task in fMRI settings to assess maternal responses to pictures of facial expressions of own child and an unknown child in an empathic mirroring condition (Join) and a non-mirroring observation condition (Observe). In each condition, faces of neutral, ambiguous, distressed, and joyful expressions of each child were repeatedly displayed in a random order. The response of SMA during empathic mirroring (Join) vs. non-mirroring (Observe) of own child was reduced among BT/OUD vs. CG. Within MBN, the left VP, critical for parental sensitivity, had a similar deficit. This study outlines potential mechanisms for investigating the risks of deficits in the neural responses to actual maternal sensitivity and parenting behavior in mothers with OUD, and potential targets for interventions that reduce stress and augment maternal behavior and child outcome.

The influence of social relationships on substance use behaviors among pregnant women with opioid use disorder

OBJECTIVE

To describe the social network characteristics of pregnant women with opioid use disorder (OUD) and explore how changes in social relationships during pregnancy may influence substance use behaviors.

METHODS

Between 2017 and 2018, we conducted an exploratory pilot study among 50 pregnant women with OUD. Participants completed a detailed social network inventory to describe the behaviors (e.g. substance-using), social support characteristics (e.g. financial, emotional, informational) and roles (e.g. family member, friend) of network members. The primary outcome was a self-reported decrease in substance use during pregnancy. Pearson correlations were used to test for associations between covariates reflecting different aspects of participants' social networks and decreased substance use during pregnancy.

RESULTS

Most participants (84.0 %) decreased substance use during pregnancy and stated that pregnancy motivated them to engage in treatment (94.0 %). Participants had a median of 8 (IQR: 4-18) network members with differing proportions of those who did and did not use substances. Pregnancy prompted participants to significantly increase contact with (26.4 % vs. 5.0 %), have increased support from (35.7 % vs. 7.5 %), and a have a feeling of increased closeness with (26.1 % vs. 3.3 %) network members who did not use substances. However, decreased substance use during pregnancy was most strongly (negatively) associated with the proportion of network members who used substances and provided informational support (r=-0.25, p = 0.08) and a feeling of closeness (r=-0.26, p = 0.08).

CONCLUSIONS

Our findings indicate that pregnancy has a profound influence on women's substance use behaviors and that changes in social relationships due to pregnancy may influence substance use.

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.

Racial and Ethnic Disparities in Maternal and Infant Outcomes Among Opioid-Exposed Mother-Infant Dyads in Massachusetts (2017-2019)

Objectives. To examine the extent to which differences in medication for opioid use disorder (MOUD) in pregnancy and infant neonatal opioid withdrawal syndrome (NOWS) outcomes are associated with maternal race/ethnicity.Methods. We performed a secondary analysis of a statewide quality improvement database of opioid-exposed deliveries from January 2017 to April 2019 from 24 hospitals in Massachusetts. We used multivariable mixed-effects logistic regression to model the association between maternal race/ethnicity (non-Hispanic White, non-Hispanic Black, or Hispanic) and prenatal receipt of MOUD, NOWS severity, early intervention referral, and biological parental custody at discharge.Results. Among 1710 deliveries to women with opioid use disorder, 89.3% (n = 1527) were non-Hispanic White. In adjusted models, non-Hispanic Black women (AOR = 0.34; 95% confidence interval [CI] = 0.18, 0.66) and Hispanic women (AOR = 0.43; 95% CI = 0.27, 0.68) were less likely to receive MOUD during pregnancy compared with non-Hispanic White women. We found no statistically significant associations between maternal race/ethnicity and infant outcomes.Conclusions. We identified significant racial/ethnic differences in MOUD prenatal receipt that persisted in adjusted models. Research should focus on the perspectives and treatment experiences of non-Hispanic Black and Hispanic women to ensure equitable care for all mother-infant dyads.

Prevalence and Geographic Distribution of Obstetrician-Gynecologists Who Treat Medicaid Enrollees and Are Trained to Prescribe Buprenorphine

IMPORTANCE

The incidence of opioid use during pregnancy is increasing, and drug overdoses are a leading cause of postpartum mortality. Most women who are pregnant do not receive medications for treatment of opioid use disorder, despite the mortality benefit that these agents confer. Furthermore, buprenorphine is associated with milder symptoms of neonatal abstinence syndrome (NAS) compared with methadone.

OBJECTIVE

To describe the prevalence and geographic distribution across the US of obstetrician-gynecologists who can prescribe buprenorphine (henceforth described as X-waivered) in 2019.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional, nationwide study linking physician-specific data to county- and state-level data was conducted from September 1, 2019, to March 31, 2020. Data were obtained on 31 211 obstetrician-gynecologists who accept Medicaid insurance through the Centers for Medicare & Medicaid Services Physician Compare data set and linked to the Drug Addiction Treatment Act buprenorphine-waived clinician list.

EXPOSURES

State-level NAS incidence and county-level uninsured rates and rurality.

MAIN OUTCOMES AND MEASURES

Prevalence and geographic distribution of obstetrician-gynecologists who are trained to prescribe buprenorphine.

RESULTS

Among the 31 211 identified obstetrician-gynecologists, 18 710 (59.9%) were women. Most had hospital privileges (23 236 [74.4%]) and worked in metropolitan counties (28 613 [91.7%]). Only 560 of the identified obstetrician-gynecologists (1.8%) were X-waivered. Obstetrician-gynecologists in counties with fewer than 5% uninsured residents had nearly twice the odds of being X-waivered (adjusted odds ratio [aOR], 1.59; 95% CI, 1.04-2.44; P = .04) compared with those in counties with greater than 15% uninsured residents. Compared with those located in metropolitan counties, obstetrician-gynecologists in suburban counties (eg, urban population of ≥20 000 and adjacent to a metropolitan area) were more likely to be X-waivered (aOR, 1.85; 95% CI, 1.26-2.71; P = .002). Compared with states with an NAS rate of 5 per 1000 births or less, obstetrician-gynecologists in states with an NAS rate of 15 per 1000 births or greater had nearly 5 times the odds of being X-waivered (aOR, 4.94; 95% CI, 3.60-6.77; P < .001). Obstetrician-gynecologists without hospital privileges were more likely to be X-waivered (aOR, 1.32; 95% CI, 1.08-1.61; P = .007).

CONCLUSIONS AND RELEVANCE

Fewer than 2% of obstetrician-gynecologists who accept Medicaid are able to prescribe buprenorphine, and their geographic distribution appears to be skewed in favor of suburban counties. This finding suggests that there is an opportunity for health systems and professional societies to incentivize X-waiver trainings among obstetrician-gynecologists to increase patients' access to buprenorphine, especially during pregnancy.

The MATernaL and Infant NetworK to Understand Outcomes Associated with Treatment of Opioid Use Disorder During Pregnancy (MAT-LINK): Surveillance Opportunity

Pregnant women with opioid use disorder (OUD) are at risk of overdose, infectious diseases, and inadequate prenatal care. Additional risks include adverse pregnancy and infant outcomes, such as preterm birth and neonatal abstinence syndrome. Management and treatment of OUD during pregnancy are associated with improved maternal and infant outcomes. Professional organizations, including the American College of Obstetricians and Gynecologists, recommend offering opioid agonist pharmacotherapy (i.e., methadone or buprenorphine) combined with behavioral therapy as standard treatment for pregnant women with OUD. Other medications and herbal supplements have also been used by pregnant women for OUD. Determining which OUD treatments optimize maternal and infant outcomes is challenging given the host of potential factors that affect these outcomes. The Centers for Disease Control and Prevention initiated the MATernaL and Infant NetworK to Understand Outcomes Associated with Treatment of Opioid Use Disorder during Pregnancy (MAT-LINK) to monitor more than 2000 mothers and their infants, using data collected from geographically diverse clinical sites. Information learned from MAT-LINK will inform the future management and treatment of pregnant women with OUD.

Assessment of Racial and Ethnic Disparities in the Use of Medication to Treat Opioid Use Disorder Among Pregnant Women in Massachusetts

Importance

Racial and ethnic disparities persist across key health and substance use treatment outcomes for mothers and infants. The use of medications, such as methadone or buprenorphine, for the treatment of opioid use disorder (OUD) has been associated with improvements in the outcomes of mothers and infants; however, only half of all pregnant women with OUD receive these medications. The extent to which maternal race or ethnicity is associated with the use of medication to treat OUD, the duration of the use of medication to treat OUD, and the type of medication used to treat OUD during pregnancy are unknown.

Objective

To examine the extent to which maternal race and ethnicity is associated with the use of medications for the treatment of OUD in the year before delivery among pregnant women with OUD.

Design, Setting, and Participants

This retrospective cohort study used a linked population-level statewide data set of pregnant women with OUD who delivered a live infant in Massachusetts between October 1, 2011, and December 31, 2015. Of 274 234 total deliveries identified, 5247 deliveries among women with indicators of having OUD were included in the analysis. Maternal race and ethnicity were defined as white non-Hispanic, black non-Hispanic, or Hispanic based on self-reported data on birth certificates.

Main Outcomes and Measures

Main outcomes were the receipt of any medication for OUD, the consistency of the use of medication (at least 6 continuous months of use before delivery, inconsistent use, or no use) for the treatment of OUD, and the type of medication (methadone or buprenorphine) used to treat OUD. Multivariable models were adjusted for maternal sociodemographic characteristics, comorbidities, and any significant interactions between the covariates and race and ethnicity.

Results

The sample included 5247 pregnant women with OUD who delivered a live infant in Massachusetts during the study period. The mean (SD) maternal age at delivery was 28.7 (5.0) years; 4551 women (86.7%) were white non-Hispanic, 462 women (8.8%) were Hispanic, and 234 women (4.5%) were black non-Hispanic. A total of 3181 white non-Hispanic women (69.9%) received any type of medication for the treatment of OUD in the year before delivery compared with 228 Hispanic women (49.4%) and 108 black non-Hispanic women (46.2%). Compared with white non-Hispanic women, black non-Hispanic and Hispanic women had a substantially lower likelihood (adjusted odds ratio [aOR], 0.37; 95% CI, 0.28-0.49 and aOR, 0.42; 95% CI, 0.35-0.52, respectively) of receiving any medication for the treatment of OUD. Stratification by maternal age identified greater disparities among younger women. Black non-Hispanic and Hispanic women also had a lower likelihood (aOR, 0.24; 95% CI, 0.17-0.35 and aOR, 0.34; 95% CI, 0.27-0.44, respectively) of consistent use of medication for the treatment of OUD compared with white non-Hispanic women. With respect to the type of medication used to treat OUD, black non-Hispanic and Hispanic women had a lower likelihood (aOR, 0.60; 95% CI, 0.40-0.90 and aOR, 0.77; 95% CI, 0.58-1.01, respectively) than white non-Hispanic women of receiving buprenorphine treatment compared with methadone treatment.

Conclusions and Relevance

This study found racial and ethnic disparities in the use of medications to treat OUD during pregnancy, with black non-Hispanic and Hispanic women significantly less likely to use medications consistently or at all compared with white non-Hispanic women. Further investigation of patient, clinician, treatment program, and system-level factors associated with these findings is warranted.

Substance use disorder treatment services for pregnant and postpartum women in residential and outpatient settings

The increasing prevalence of opioid use disorders among pregnant and postpartum women (PPW) has generated a need for greater availability of specialized programs offering evidence-based and comprehensive substance use disorder treatment services tailored to this population. In this study, we used data from the 2007 to 2018 National Survey of Substance Abuse Treatment Services to describe recent time trends and the geographic distribution of treatment facilities with specialized programs for PPW. We also compared differences in the availability of opioid agonist medication treatments (MT), key ancillary services, and health insurance acceptance between PPW Programs and Other Programs, overall and by residential and outpatient settings. We found that the prevalence of PPW Programs increased from 17% in 2007 to 23% in 2018, for a total of 3,429 PPW Programs and 11,230 Other Programs in 2018. The prevalence of PPW Programs was lowest in some states in the South and Midwest. Compared to Other Programs, PPW Programs were more likely to accept Medicaid (75% vs. 64%) and offer opioid agonist MTs methadone (24% vs. 6%), buprenorphine (44% vs. 30%), or both (18% vs. 4%). PPW Programs were also more likely to offer other key ancillary services such as childcare (16% vs. 3%), transportation (50% vs. 42%), and domestic violence assistance (51% vs. 35%). Compared to PPW Programs in outpatient settings, PPW Programs in residential settings were more likely to offer these key ancillary services but less likely to offer methadone or accept Medicaid. Our findings reflect considerable variation in the availability of PPW Programs over time and across states, as well as substantial gaps in key services offered in PPW Programs, let alone in Other Programs.

Methadone, Buprenorphine, or Detoxification for Management of Perinatal Opioid Use Disorder: A Cost-Effectiveness Analysis

OBJECTIVE

To estimate whether methadone, buprenorphine, or detoxification treatment is the most cost-effective approach to the management of opioid use disorder (OUD) during pregnancy.

METHODS

We created a decision analytic model that compared the cost effectiveness (eg, the marginal cost of the strategy in U.S. dollars divided by the marginal effectiveness of the strategy, measured in quality-adjusted life-years [QALYs]) of initiation of methadone, buprenorphine, or detoxification in treatment of OUD during pregnancy. Probabilities, costs, and utilities were estimated from the existing literature. Incremental cost-effective ratios for each strategy were calculated, and a ratio of $100,000 per QALY was used to define cost effectiveness. One-way sensitivity analyses and a Monte Carlo probabilistic sensitivity analysis were performed.

RESULTS

Under base assumptions, initiation of buprenorphine was more effective at a lower cost than either methadone or detoxification and thus was the dominant strategy. Buprenorphine was no longer cost effective if the cost of methadone was 8% less than the base-case estimate ($1,646/month) or if the overall costs of detoxification were 121% less than the base-case estimate for the detoxification cost multiplier, which was used to increase the values of both inpatient and outpatient management of detoxification by a factor of 2. Monte Carlo analyses revealed that buprenorphine was the cost-effective strategy in 70.5% of the simulations. Direct comparison of buprenorphine with methadone demonstrated that buprenorphine was below the incremental cost-effective ratio in 95.1% of simulations; direct comparison between buprenorphine and detoxification demonstrated that buprenorphine was below the incremental cost-effective ratio in 45% of simulations.

CONCLUSION

Under most circumstances, we estimate that buprenorphine is the cost-effective strategy when compared with either methadone or detoxification as treatment for OUD during pregnancy. Nonetheless, the fact that buprenorphine was not the cost-effective strategy in almost one out of three of simulations suggests that the robustness of our model may be limited and that further evaluation of the cost-effective approach to the management of OUD during pregnancy is needed.

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.

Analgesia, Opioids, and Other Drug Use During Pregnancy and Neonatal Abstinence Syndrome

When opioid misuse rises in the United States, pregnant women and their neonates are affected. This article summarizes the use of Food and Drug Administration-approved products, including methadone, buprenorphine, and the combination formulation of buprenorphine and naloxone to treat adult opioid use disorder during the perinatal period. All labels include pregnancy, neonatal, and lactation information and note the accepted use of these medications during the perinatal period if the benefits outweigh the risks. A summary of the neonatal abstinence syndrome definition, its assessment tools, treatment approaches, and future genetic directions are provided.

Breastmilk feeding for mothers and infants with opioid exposure: What is best?

With rare exception, breastfeeding is the optimal way to feed infants, and has special benefits for women and infants with perinatal opioid exposure. Infants breastfed and/or fed their mother's own breastmilk experience less severe opioid withdrawal symptoms, have shorter hospital stays, and are less likely to be treated with medication for withdrawal. The specific impact of mothers' milk feeding on opioid withdrawal may be related to the act of breastfeeding and associated skin-to-skin contact, qualities of breastmilk, healthier microbiome, small amounts of opioid drug in breastmilk, or a combination of these. Women with opioid use disorder face significant breastfeeding obstacles, including psychosocial, behavioral, concomitant medications, and tobacco use and thus may require high levels of support to achieve their breastfeeding goals. They often don't receive information to make informed infant feeding decisions. Hospital practices such as prenatal education, rooming-in and having a policy that minimizes barriers to breastfeeding are associated with increased breastfeeding rates.

Methadone Versus Buprenorphine for Opioid Use Dependence and Risk of Neonatal Abstinence Syndrome

BACKGROUND

Our objective was to estimate the association between methadone and neonatal abstinence syndrome compared with buprenorphine using a probabilistic bias analysis to account for unmeasured confounding by severity of addiction.

METHODS

We used a cohort of live-born infants exposed in utero to methadone or buprenorphine for maternal opioid maintenance therapy at Magee-Womens Hospital in Pittsburgh, PA, from 2013 to 2015 (n = 716). We determined exposure and outcome status using pharmacy billing claims. We used log-binomial regression models to assess association of treatment with neonatal abstinence syndrome after adjusting for parity, maternal race, age, delivery year, employment, hepatitis c, smoking, marital, and insurance status. We implemented probabilistic bias analysis, informed by an internal validation study, to assess the impact of unmeasured confounding by severity of addiction.

RESULTS

Infants exposed to methadone in utero were more likely to experience neonatal abstinence syndrome compared with those exposed to buprenorphine (RR, 1.3; 95% CI, 1.2, 1.5). After adjustment, infants exposed to methadone were more likely (adjusted RR, 1.3; 95% CI, 1.1, 1.5) than infants exposed to buprenorphine to have the syndrome. In the validation cohort (n = 200), severe addiction was more common in methadone- versus buprenorphine-exposed deliveries (77% vs. 32%). However, adjustment for severe addiction in the bias analysis only slightly attenuated the association (RR, 1.2; 95% CI, 1.0, 1.4), supporting conventional analysis.

CONCLUSIONS

Methadone is associated with increased risk of neonatal abstinence syndrome compared with buprenorphine in infants exposed in utero. This association is subject to minimal bias due to unmeasured confounding by severity of addiction.

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.

Prenatal intent and postpartum receipt of long-acting reversible contraception among women receiving medication-assisted treatment for opioid use disorder

BACKGROUND

Many women with opioid use disorder (OUD) do not use highly effective postpartum contraception such as long-acting reversible contraception (LARC). We evaluated factors associated with prenatal intent and postpartum receipt of LARC among women receiving medication-assisted treatment (MAT) for OUD.

STUDY DESIGN

This was a retrospective cohort study of 791 pregnant women with OUD on MAT who delivered at an academic institution without immediate postpartum LARC services between 2009 and 2012. LARC intent was defined as a documented plan for postpartum LARC during pregnancy and LARC receipt was defined as documentation of LARC placement by 8 weeks postpartum. We organized contraceptive methods into five categories: LARC, female sterilization, short-acting methods, barrier methods and no documented method. Multivariable logistic regression identified characteristics predictive of prenatal LARC intent and postpartum LARC receipt.

RESULTS

Among 791 pregnant women with OUD on MAT, 275 (34.8%) intended to use postpartum LARC and only 237 (29.9%) attended the postpartum visit. Among 275 women with prenatal LARC intent, 124 (45.1%) attended their postpartum visit and 50 (18.2%) received a postpartum LARC. Prenatal contraceptive counseling (OR 6.67; 95% CI 3.21, 13.89) was positively associated with LARC intent. Conversely, older age (OR 0.95; 95% CI 0.91, 0.98) and private practice provider (OR 0.48; 95% CI 0.32, 0.72) were negatively associated with LARC intent. Although parity was not predictive of LARC intent, primiparous patients (CI 0.49; 95% CI 0.26, 0.97) were less likely to receive postpartum LARC.

CONCLUSIONS

Discrepancies exist between prenatal intent and postpartum receipt of LARC among pregnant women with OUD on MAT. Immediate postpartum LARC services may reduce LARC access barriers.

IMPLICATIONS

Despite prenatal interest in using LARC, most pregnant women with OUD on MAT did not receive postpartum LARC. The provision of immediate postpartum LARC services may reduce barriers to postpartum LARC receipt such as poor attendance at the postpartum visit.

Prevalence of alcohol use in pregnant women with substance use disorder

BACKGROUND

Prenatal care programs for women with opioid use disorder (OUD) often focus treatment/counseling plans around illicit substances, while concurrent use of alcohol might present an equal or greater risk to the fetus.

METHODS

This study evaluated self-reported prevalence of alcohol use in patients participating in a comprehensive prenatal care program for women with substance use disorder (SUD; n = 295), of which 95% are treated for OUD, and pregnant women being served through general obstetrical clinics at the University of New Mexico (n = 365). During the screening phase of a prospective study, patients were asked to report alcohol use in the periconceptional period, and between the last menstrual period and pregnancy recognition.

RESULTS

The screening interview was conducted at 22.3 (median = 22; Q1 = 16; Q3 = 29) gestational weeks. Among patients screened at the SUD clinic, 28.8% and 24.1% reported at least one binge drinking episode in the periconceptional period and in early pregnancy, respectively. The prevalence of binge drinking was similar in the general obstetrics population (24.7% and 24.4%, respectively). Among those who reported drinking in early pregnancy, median number of binge drinking episodes was higher among patients screened at the SUD clinic (median = 3; Q1 = 1; Q3 = 10) compared to the general obstetrics group (median = 1; Q1 = 1; Q3 = 3; p < 0.001).

CONCLUSIONS

This study demonstrates a high prevalence of prenatal alcohol use in early pregnancy in both groups, while patients with SUD/OUD consume more alcohol. These findings underscore the need for targeted screening and intervention for alcohol use in all pregnant women, especially those with SUD/OUD.

Neonatal Outcomes in a Medicaid Population With Opioid Dependence

Confounding may account for the apparently improved infant outcomes after prenatal exposure to buprenorphine versus methadone. We used Massachusetts Medicaid Analytic eXtract (MAX) data to identify a cohort of opioid-dependent mother-infant pairs (2006-2011), supplemented with confounder data from an external Boston, Massachusetts, cohort (2015-2016). Associations between prenatal buprenorphine exposure versus methadone exposure and infant outcomes in the MAX cohort were adjusted for measured MAX confounders and were additionally adjusted for unmeasured confounders with bias analysis using external cohort data. A total of 477 women in MAX were treated with methadone and 543 with buprenorphine. More buprenorphine users than methadone users were white and used psychotropic medications. After adjustment for MAX confounders, risk ratios among infants exposed to buprenorphine versus those exposed to methadone were 0.45 (95% confidence interval (CI): 0.34, 0.61) for preterm birth (birth at <37 weeks) and 0.75 (95% CI: 0.51, 1.11) for low birth weight for gestational age. The mean difference in infant hospitalization was -7.35 days (95% CI: -9.16, -5.55). After further adjustment with bias analysis, the risk ratios were 0.53 (95% CI: 0.39, 0.71) for preterm birth and 1.14 (95% CI: 0.77, 1.69) for low birth weight for gestational age, and the mean difference in infant hospitalization was -3.66 days (95% CI: -5.46, -1.87). External confounder data can be used to adjust for unmeasured confounding in studies of prenatal outcomes among women on opioid agonist therapy based on administrative databases.

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.

Maternal buprenorphine treatment and infant outcome

BACKGROUND AND OBJECTIVES

Maternal buprenorphine maintenance predisposes the infant to exhibit neonatal abstinence syndrome (NAS), but there is insufficient published information regarding the nature of NAS and factors that contribute to its severity in buprenorphine-exposed infants.

METHODS

The present study evaluated forty-one infants of buprenorphine-maintained women in comprehensive substance use disorder treatment who participated in an open-label study examining the effects of maternal buprenorphine maintenance on infant outcomes. Modifiers of the infant outcomes, including maternal treatment and substance use disorder parameters, were also evaluated.

RESULTS

Fifty-nine percent of offspring exhibited NAS that required pharmacologic management. Both maternal buprenorphine dose as well as prenatal polysubstance exposure to illicit substance use/licit substance misuse were independently associated with NAS expression. Polysubstance exposure was associated with more severe NAS expression after controlling for the effects of buprenorphine dose. Other exposures, including cigarette smoking and SRI use, were not related to outcomes. Maternal buprenorphine dose was positively associated with lower birth weight and length.

CONCLUSIONS

Polysubstance exposure was the most potent predictor of NAS severity in this sample of buprenorphine-exposed neonates. This finding suggests the need for interventions that reduce maternal polysubstance use during medication assisted treatment for opioid use disorder, and highlights the necessity of a comprehensive approach, beyond buprenorphine treatment alone, for the optimal care for pregnant women with opioid use disorders.

Maternal buprenorphine treatment and fetal neurobehavioral development

BACKGROUND

Gestational opioid use/misuse is escalating in the United States; however, little is understood about the fetal effects of medications used to treat maternal opioid use disorders.

OBJECTIVE

The purpose of this study was to determine the effect of maternal buprenorphine administration on longitudinal fetal neurobehavioral development.

STUDY DESIGN

Forty-nine buprenorphine-maintained women who attended a substance use disorder treatment facility with generally uncomplicated pregnancies underwent fetal monitoring for 60 minutes at times of trough and peak maternal buprenorphine levels. Data were collected at 24, 28, 32, and 36 weeks gestation. Fetal neurobehavioral indicators (ie, heart rate, motor activity, and their integration [fetal movement-fetal heart rate coupling]) were collected via an actocardiograph, digitized and quantified. Longitudinal data analysis relied on hierarchic linear modeling.

RESULTS

Fetal heart rate, heart rate variability, and heart rate accelerations were significantly reduced at peak vs trough maternal buprenorphine levels. Effects were significant either by or after 28 weeks gestation and tended to intensify with advancing gestation. Fetal motor activity and fetal movement-fetal heart rate coupling were depressed from peak to trough at 36 weeks gestation. Polysubstance exposure did not significantly affect fetal neurobehavioral parameters, with the exception that fetuses of heavier smokers moved significantly less than those of lighter smokers at 36 weeks gestation. By the end of gestation, higher maternal buprenorphine dose was related to depression of baseline fetal cardiac measures at trough.

CONCLUSION

Maternal buprenorphine administration has acute suppressive effects on fetal heart rate and movement, and the magnitude of these effects increases as gestation progresses. Higher dose (≥13 mg) appears to exert greater depressive effects on measures of fetal heart rate and variability. These findings should be balanced against comparisons to gestational methadone effects, relatively good outcomes of buprenorphine-exposed infants, and recognition of the benefits of medication-assisted treatment for pregnant women with opioid use disorders in optimizing pregnancy outcomes.

The opioid epidemic and neonatal abstinence syndrome in the USA: a review of the continuum of care

As the prescription opioid epidemic grew in the USA, its impact extended to pregnant women and their infants. This review summarises how increasing rates of neonatal abstinence syndrome resulted in a need to improve care to pregnant women and opioid-exposed infants. We discuss the variations in care delivery with particular emphasis on screening at-risk mothers, scoring systems for neonatal drug withdrawal, type and duration of pharmacotherapy, and discharge safety.

Maternal Buprenorphine Maintenance and Lactation

BACKGROUND

In addition to the well-known benefits of human milk and breastfeeding for the mother and infant, breastfeeding may mitigate neonatal abstinence syndrome severity in prenatally opioid-exposed infants. However, lack of conclusive data regarding the extent of the presence of buprenorphine and active metabolites in human milk makes the recommendation of breastfeeding for buprenorphine-maintained women difficult for many providers.

OBJECTIVE

This study seeks to determine the concentrations of buprenorphine and its active metabolites (norbuprenorphine, buprenorphine-glucuronide, and norbuprenorphine-glucuronide) in human milk, maternal plasma, and infant plasma of buprenorphine-maintained women and their infants.

METHODS

Up to 10 buprenorphine-maintained women provided paired breast milk and plasma samples at 2, 3, 4, 14, and 30 days postdelivery, and 9 infants provided plasma samples on day 14 of life. All samples were analyzed via liquid chromatography tandem mass spectrometry to determine concentrations of buprenorphine, norbuprenorphine, buprenorphine-glucuronide, and norbuprenorphine-glucuronide by a fully validated method.

RESULTS

Concentrations of buprenorphine and metabolites are low in human milk and maternal plasma. Breastfed infant plasma concentrations of buprenorphine were low or undetectable and metabolite concentrations undetectable at 14 days of infant age. There were significant correlations between maternal buprenorphine dose and maternal plasma and human milk buprenorphine concentrations.

CONCLUSION

These data find low concentrations of buprenorphine and metabolites in human milk and lend support to the recommendation for lactation among stable buprenorphine-maintained women. However, the correlation between maternal dose and maternal plasma and human milk buprenorphine concentrations bears further study.