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.).

A Dyadic Framework of Care for Opioid-exposed Birthing Persons and Their Infants and Children.

OBJECTIVE: To develop a dyadic-centered framework focused on clinical care, surveillance, and research for birthing persons with opioid use disorder (OUD) and their infants and children. STUDY DESIGN: Between February and March 2023, an analysis was conducted within the US Department of Health and Human Services (HHS) of activities directed at opioid-exposed birthing persons and their infants and children (the dyad) to identify: 1) number of activities, stratified by type and 2) characteristics across health and supportive activities that serve the dyad vs birthing persons or infants and children individually. Descriptive and thematic analyses were used to assess quantity and characteristics of fiscal year 2023-2024 activities aggregated across eleven HHS agencies. RESULTS: Of 181 activities examined, 75 met inclusion criteria specific to serving birthing persons with OUD and opioid-exposed infants and children. Sixty-two percent of activities were dyad focused. Five categories of dyadic activities were identified: research (45%), education and training (28%), health and supportive services (21%), surveillance (4%), and quality improvement (2%). Eight specific characteristics were key to dyadic activities: a life course and generational approach, emphasis on relationship, dyadic outcomes, service wraparound, payment structures supporting dyadic care, data linkage, and social determinants of health. CONCLUSIONS: This analysis of HHS activities directed at birthing persons with OUD and opioid-exposed infants and children showed that most programs had a dyadic focus. Synthesizing elements identified from activities serving the dyad facilitated the development of a dyadic framework integrating clinical care, public health surveillance, and research.

Comprehensive Treatment for Pregnant and Parenting Women with Substance Use Disorders and Their Children: The UNC Horizons Story.

OBJECTIVES: To describe how the UNC Horizons program, a comprehensive women-centered program for pregnant and parenting women with substance use disorders, and its patient population have changed over time and summarize basic neonatal outcomes for infants born to women in treatment at Horizons. METHODS: Yearly Annual Reports from fiscal years of 1994 to 2017 were abstracted. Patient characteristics and infant outcomes compared to normative North Carolina data were examined. RESULTS: Highlights of findings include: The percentage of women for whom opioids were the primary substance of use increased from 0% in 1995-1996 to 62% in 2016-17, while cocaine decreased from 66 to 12%. Intravenous substance use history increased from 7% in 1994-1995 to 41% in 2016-2017. The number of women reporting a history of incarceration rose from 10-20% in the early years to 40%-50% beginning in 2007-2008. The proportion of women reporting a desire to hurt themselves rose from 20% in 2004-2005 to 40% in 2016-2017. Self-reported suicide attempt history remained consistent at 32% across years. While reporting of childhood physical abuse remained at 38% across years, reporting of sexual abuse and domestic violence trended upward. Horizons did not differ from North Carolina in the likelihood of patients giving birth prematurely [χ2(13) = 20.6,p = .082], or the likelihood of a patient giving birth to a low birthweight infant [χ2(13) = 14.7,p = .333]. CONCLUSIONS FOR PRACTICE: Breaking the cycle of addiction for women and children must focus on helping women with substance use problems develop a sense of hope that their lives can improve, and a sense of feeling safe and nurtured.

Systematic examinations of programs that provide treatment services to pregnant and parenting women with substance use disorders have typically been focused on a limited set of outcomes and have been cross-sectional in nature. The current paper presents a detailed examination of the patient populations over a 23-year period, with particular attention to the changes over time in the women served. The birth weight and prematurity of infants born to the women in this program were likewise examined over time, and in comparison to state-level data.

Hair Cortisol Concentrations in Opioid-Exposed versus Nonexposed Mother-Infant Dyads.

OBJECTIVE: To pilot measurement of hair cortisol concentration (HCC) in pregnant women with opioid use disorder and their infants over time and study the potential utility of hair cortisol as a biomarker of chronic stress in this population. STUDY DESIGN: In this pilot prospective cohort study of mother-infant dyads with and without prenatal opioid exposure, we obtained mother-infant HCCs at delivery and again within 1 to 3 months' postpartum. HCCs were compared between the opioid and control groups and between the two time points. RESULTS: There were no significant differences between opioid and control group maternal or infant HCCs at either time point. However, within the opioid-exposed group, there was a significant increase in infant HCCs across the two time points. CONCLUSION: This pilot study describes our experience with the measurement of HCCs in opioid-exposed mother-infant dyads. KEY POINTS: · Maternal stress impacts fetal and child health.. · Many stressors in pregnant women with opioid use disorder.. · Hair cortisol may be a useful stress biomarker..

Racial and Ethnic Inequities in Buprenorphine and Methadone Utilization Among Reproductive-Age Women with Opioid Use Disorder: an Analysis of Multi-state Medicaid Claims in the USA.

BACKGROUND: Associations between race/ethnicity and medications to treat OUD (MOUD), buprenorphine and methadone, in reproductive-age women have not been thoroughly studied in multi-state samples. OBJECTIVE: To evaluate racial/ethnic variation in buprenorphine and methadone receipt and retention in a multi-state U.S. sample of Medicaid-enrolled, reproductive-age women with opioid use disorder (OUD) at the beginning of OUD treatment. DESIGN: Retrospective cohort study. SUBJECTS: Reproductive-age (18-45 years) women with OUD, in the Merative™ MarketScan® Multi-State Medicaid Database (2011-2016). MAIN MEASURES: Differences by race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, "other" race/ethnicity) in the likelihood of receiving buprenorphine and methadone during the start of OUD treatment (yes/no) were estimated using multivariable logistic regression. Differences in time to medication discontinuation (days) by race/ethnicity were evaluated using multivariable Cox regression. RESULTS: Of 66,550 reproductive-age Medicaid enrollees with OUD (84.1% non-Hispanic White, 5.9% non-Hispanic Black, 1.0% Hispanic, 5.3% "other"), 15,313 (23.0%) received buprenorphine and 6290 (9.5%) methadone. Non-Hispanic Black enrollees were less likely to receive buprenorphine (adjusted odds ratio, aOR = 0.76 [0.68-0.84]) and more likely to be referred to methadone clinics (aOR = 1.78 [1.60-2.00]) compared to non-Hispanic White participants. Across both buprenorphine and methadone in unadjusted analyses, the median discontinuation time for non-Hispanic Black enrollees was 123 days compared to 132 days and 141 days for non-Hispanic White and Hispanic enrollees respectively (χ2 = 10.6; P = .01). In adjusted analyses, non-Hispanic Black enrollees experienced greater discontinuation for buprenorphine and methadone (adjusted hazard ratio, aHR = 1.16 [1.08-1.24] and aHR = 1.16 [1.07-1.30] respectively) compared to non-Hispanic White peers. We did not observe differences in buprenorphine or methadone receipt or retention for Hispanic enrollees compared to the non-Hispanic White enrollees. CONCLUSIONS: Our data illustrate inequities between non-Hispanic Black and non-Hispanic White Medicaid enrollees with regard to buprenorphine and methadone utilization in the USA, consistent with literature on the racialized origins of methadone and buprenorphine treatment.

Prescribed and Penalized: The Detrimental Impact of Mandated Reporting for Prenatal Utilization of Medication for Opioid Use Disorder.

OBJECTIVES: Some states, including Massachusetts, require automatic filing of child abuse and neglect for substance-exposed newborns, including infants exposed in-utero to clinician-prescribed medications to treat opioid use disorder (MOUD). The aim of this article is to explore effects of these mandated reporting policies on pregnant and postpartum people receiving MOUD. METHODS: We used modified grounded research theory, literature findings, and constant comparative methods to extract, analyze and contextualize perinatal experiences with child protection systems (CPS) and explore the impact of the Massachusetts mandated reporting policy on healthcare experiences and OUD treatment decisions. We drew from 26 semi-structured interviews originally conducted within a parent study of perinatal MOUD use in pregnancy and the postpartum period. RESULTS: Three themes unique to CPS reporting policies and involvement emerged. First, mothers who received MOUD during pregnancy identified mandated reporting for prenatally prescribed medication utilization as unjust and stigmatizing. Second, the stress caused by an impending CPS filing at delivery and the realities of CPS surveillance and involvement after filing were both perceived as harmful to family health and wellbeing. Finally, pregnant and postpartum individuals with OUD felt pressure to make medical decisions in a complex environment in which medical recommendations and the requirements of CPS agencies often compete. CONCLUSIONS FOR PRACTICE: Uncoupling of OUD treatment decisions in the perinatal period from mandated CPS reporting at time of delivery is essential. The primary focus for families affected by OUD must shift from surveillance and stigma to evidence-based treatment and access to supportive services and resources.

What is already known on this subject? Child protection systems (CPS) reporting is associated with barriers to prenatal care and family resources and services. Some state policies in the United States mandate reporting to CPS for prenatal substance exposure, including prescribed medications for opioid use disorder.What this study adds? This study centers the experiences of pregnant and postpartum people with opioid use disorder with mandated reporting policies for prenatal substance exposure, describes the harms to families associated with these policies, and makes recommendations for policy change. Findings emphasize the need to uncouple medical decisions from CPS reporting and involvement.

Standardizing the Clinical Definition of Opioid Withdrawal in the Neonate.

OBJECTIVE: To standardize the clinical definition of opioid withdrawal in neonates to address challenges in clinical care, quality improvement, research, and public policy for this patient population. STUDY DESIGN: Between October and December 2020, we conducted 2 modified-Delphi panels using ExpertLens, a virtual platform for performing iterative expert engagement panels. Twenty clinical experts specializing in care for the substance-exposed mother-neonate dyad explored the necessity of key evidence-based clinical elements in defining opioid withdrawal in the neonate leading to a diagnosis of neonatal abstinence syndrome (NAS)/neonatal opioid withdrawal syndrome (NOWS). Expert consensus was assessed using descriptive statistics, the RAND/UCLA Appropriateness Method, and thematic analysis of participants' comments. RESULTS: Expert panels concluded the following were required for diagnosis: in utero exposure (known by history, not necessarily by toxicology testing) to opioids with or without the presence of other psychotropic substances, and the presence of at least two of the most common clinical signs characteristic of withdrawal (excessive crying, fragmented sleep, tremors, increased muscle tone, gastrointestinal dysfunction). CONCLUSIONS: Results indicate that both a known history of in utero opioid exposure and a distinct set of withdrawal signs are necessary to standardize a definition of neonatal withdrawal. Implementation of a standardized definition requires both patient engagement and a mother-neonate dyadic approach mindful of program and policy implications.

Supporting perinatal individuals with opioid use disorder and their newborns experiencing neonatal abstinence syndrome: impressions from patients and healthcare providers.

Background: Facilitating maternal-newborn involvement and care is critical for improving outcomes for perinatal individuals receiving opioid agonist therapy (OAT) and newborns experiencing Neonatal Abstinence Syndrome (NAS). Comprehensive education strategies are needed to prepare pregnant individuals receiving OAT for navigating the perinatal period.Objectives: Identify facilitators to successful care of perinatal individuals receiving OAT and newborns experiencing NAS via interviews with perinatal individuals and healthcare providers. The goal of identifying this information is to inform a future educational tool development.Methods: Ten perinatal individuals receiving OAT and ten healthcare providers participated in interviews conducted via phone or video conference using semi-structured, open-ended questions. Data were analyzed separately for the two groups and later merged across samples using a qualitative descriptive content analysis approach to identify themes.Results: Under the overarching theme of empowerment to improve outcomes for perinatal women, four themes arose from perinatal and provider interviews: 1) Preparation for Child Protective Services (CPS) involvement, 2) Healthcare providers shape experience through stigma and support 3) Caring for newborns with NAS, and 4) Managing health and resources during postpartum.Conclusion: Perinatal participants emphasized the importance of self-advocacy while navigating healthcare and social systems. Providers highlighted the importance of communicating expectations to empower patients. Education is needed for pregnant individuals receiving OAT on what to expect during pregnancy and postpartum, as well as for providers to help them optimally support their perinatal patients receiving OAT.

Perspectives among women receiving medications for opioid use disorder: Implications for development of a peer navigation intervention to improve access to family planning services.

Background Studies have consistently found high rates of unintended pregnancy among women with opioid use disorder (OUD). Few interventions have been developed to specifically engage and address the family planning (FP) needs of women in substance use disorder treatment. Objectives: Our goal was to collect formative qualitative data to identify the FP experiences, needs and service preferences of women receiving medications for OUD and to use these data to develop a FP education and navigation intervention that could be tested in diverse, resource-limited treatment settings. Methods: From August 2016 to April 2017, we conducted 21 guided qualitative interviews with women from two outpatient treatment clinics in Denver, Colorado. We recorded, transcribed, and coded all interviews. We then facilitated three focus groups (n = 16) from May to July 2017 to verify or challenge interview themes and to further inform the development of the FP intervention. Results: Most participants expressed ambivalence or low perceived risk regarding unintended pregnancy and desired more information about contraceptive methods. Many participants described mistrust or lack of engagement in the medical system and histories of trauma were a common barrier to seeking services. Focus group participants endorsed a peer-led FP navigation intervention and provided feedback to tailor existing FP educational materials to fit the specific needs of women in recovery. Conclusions/Importance: Results from this qualitative study suggest that women in recovery from OUD have unique, unmet FP education and service needs. These findings provide important information for the development of feasible and acceptable FP service delivery within diverse, resource-limited treatment settings and informed the development of a trauma-informed, peer-led FP education and navigation intervention that would be implemented in a subsequent phase of the study.

Challenges and opportunities during the COVID-19 pandemic: Treating patients for substance use disorders during the perinatal period.

The coronavirus disease 2019 (COVID-19) pandemic exacerbated the opioid use disorder epidemic and accelerated alcohol and other substance use disorders. Sudden health care service delivery changes during the COVID-19 pandemic created both challenges and opportunities for all patients with substance use disorders including the use of virtual or telemedicine visits, medication access issues and ensuring access to naloxone when supplies cannot be handed out. Unique challenges for pregnant and post-partum patients with substance use disorders includes some evidence of reduced access to medication to treat opioid use disorders and changes in delivery protocols that isolate birthing people from supports. Opportunities for all patients with substance use disorders include virtual platforms presenting positive opportunities for treatment. They are time efficient, eliminate transportation barriers, and potentially reduce childcare barriers. For pregnant and post-partum patients with substance use disorders, hybrid models of telemedicine and in-person visits reduced no-show visit rates and increased flexibility in medication dosing regimens. Thus, there is a unique opportunity to study the success of different virtual care models given the variety of implemented strategies. The COVID-19 pandemic provides an unprecedented opportunity to dramatically transform standard care approaches to help optimize care for all patients, including pregnant and post-partum people.

Trends in Opioid and Psychotropic Prescription in Pregnancy in the United States From 2001 to 2015 in a Privately Insured Population : A Cross-sectional Study.

BACKGROUND: Opioid and psychotropic prescriptions are common during pregnancy. Little is known about coprescriptions of both medications in this setting. OBJECTIVE: To describe opioid prescription among women who are prescribed psychotropics compared with women who are not. DESIGN: Cross-sectional study. SETTING: U.S. commercial insurance beneficiaries from MarketScan (2001 to 2015). PARTICIPANTS: Pregnant women at 22 weeks' gestation or greater who were insured continuously for 3 months or more before pregnancy through delivery. MEASUREMENTS: Opioid prescription, dosage thresholds (morphine milligram equivalents [MME] of ≥50/day and ≥90/day), number of opioid agents (≥2), and duration (≥30 days) among those with and without prescription of psychotropics, from 2011 to 2015. RESULTS: Among 958 980 pregnant women, 10% received opioids only, 6% psychotropics only, and 2% opioids with coprescription of psychotropics. Opioid prescription was higher among women prescribed psychotropics versus those who were not (26.5% vs. 10.7%). From 2001 to 2015, psychotropic prescription overall increased from 4.4% to 7.6%, opioid prescription without coprescription of psychotropics decreased from 11.9% to 8.4%, and opioids with coprescription decreased from 28.1% to 22.0%. Morphine milligram equivalents of 50 or greater per day decreased for women with and without coprescription (29.6% to 17.3% and 22.8% to 18.5%, respectively); MME of 90 or greater per day also decreased in both groups (15.0% to 4.7% and 11.5% to 4.2%, respectively). Women prescribed opioids only were more likely to have an antepartum hospitalization compared with those with neither prescription, as were women with coprescription versus those prescribed psychotropics only. Compared with those prescribed opioids only, women with coprescriptions were more likely to exceed MME of 90 or greater per day and to be prescribed 2 or more opioid agents and for 30 days or longer. Number and duration of opioids increased with benzodiazepine and gabapentin coprescription. LIMITATION: Inability to determine appropriateness of prescribing or overdose events. CONCLUSION: Opioids are frequently coprescribed with psychotropic medication during pregnancy and are associated with antepartum hospitalization. A substantial proportion of pregnant women are prescribed opioids at doses that increase overdose risk and exceed daily recommendations. PRIMARY FUNDING SOURCE: None.

Improving access to care through Advanced Practice Registered Nurses: Focus on perinatal patients with Opioid Use Disorder.

Perinatal substance use disorders, and all of the associated sequelae, continue to be a national health crisis that is further impacted by shifts in access to obstetrical care, particularly in rural areas. Opioid Use Disorder (OUD) specifically presents as a medical condition for which evidence-based guidelines support the use of medication treatment for opioid use disorder (MOUD) in the form of Methadone or Buprenorphine for both non-pregnant and pregnant women. However, the overall rates of access for those treatment modalities remain sparse. There is a public call to increase access to MOUD in the pregnant population affected by OUD. This article discusses the history of the Advanced Practice Registered Nurse (APRN) and how across legislative differences, these professionals are perfectly positioned to answer this call.

Perinatal Substance Use Disorders Treatment.

North Carolina has been at the forefront of offering treatment for perinatal substance use disorders for over 25 years. Wraparound services, understanding of the fourth trimester, the importance of medication-assisted treatment, and learning from past false predictions regarding illicit prenatal exposure contribute to a nurturing, supportive approach for the mother, child, and families.

The CHILD Intervention for Living Drug-free Comprehensive Assessment of Risk, Resilience, and Experience (CHILD CARRE) Measure: Initial Findings.

This paper summarizes the development and evaluation of an assessment instrument for children ages 7-12. The CHILD CARRE measure is a semi-structured interview with 7 domains. Children from the USA and Argentina (N=134) completed baseline and follow-up assessments. Substance use occurred at an average age of 8. Almost 33% of the children were taking medications for medical issues, more than 50% of them said that medical problem gets in the way of doing things they like to to do and almost 64% of the children stated that they would like to feel better. On average, children completed third grade in school, 56% of them knew how to read and 26% of the children started making money at age 8. Most children (74%) saw someone drunk or high and 23% of children reported alcohol or psychoactive substance use. Among these children using substances, such substance use occurred at an average age of 8, and in the past 30 days they used these substances an average for 5 days. The rating of level of risk on the part of the interviewer placed these children in the "risky" to "very risky" categories. Most children reported seeing their family members smoking (83%) or using alcohol (67%), and 49% reported seeing their family members high on drugs. Few children (10%) had conflicts with the law, while 46% of their family members had legal problems. Some children (30%) reported having serious problems getting along with family members, neighbors, or friends. These results suggest that this measure can serve as the first comprehensive measure to assess multiple life domains for young children at risk for or using psychoactive substances.

Pregnancy intention and opioid use disorder treatment retention in the MOTHER study.

BACKGROUND AND OBJECTIVES: Opioid use disorder (OUD) during pregnancy challenges public health. This study examines how pregnancy intention affects OUD treatment. METHODS: The primary exposure and outcome were pregnancy intention and treatment duration among MOTHER (Maternal Opioid Treatment: Human Experimental Research) participants (N = 175). RESULTS: Treatment durations were longer (21.3 vs. 16.3 weeks; p = .01) among intended (n = 29) compared to unintended (n = 146) pregnancy participants, but this was not significant in adjusted analyses. DISCUSSION AND CONCLUSIONS: Unintended pregnancies intersect with OUD and may modify one's treatment outcomes. SCIENTIFIC SIGNIFICANCE: OUD treatment may be a setting to help women implement informed family planning choices. (Am J Addict 2018;XX:1-3).

Treating women with opioid use disorder during pregnancy in Appalachia: Initial neonatal outcomes following buprenorphine + naloxone exposure.

BACKGROUND AND OBJECTIVES: Rising concerns regarding diversion and misuse of mono-buprenorphine for treatment of pregnant women with opioid use disorders have sparked interest in the use of buprenorphine + naloxone to reduce misuse and diversion rates. Examined the relationship of prenatal buprenorphine + naloxone exposure to neonatal outcomes. METHODS: This is a retrospective chart review of 26 mother infant dyads in comprehensive medication-assisted treatment with buprenorphine + naloxone during pregnancy. RESULTS: All neonatal birth outcome parameters were within normal ranges, albeit on the lower side of normal for gestational age and birth weight. Only 19% of neonates required morphine pharmacology for NAS. CONCLUSIONS: Use of buprenorphine + naloxone shows relative safety in pregnancy. SCIENTIFIC SIGNIFICANCE: These findings can help better guide prescribing practices for pregnant patients at risk for misuse or diversion of buprenorphine. (Am J Addict 2018;27:92-96).

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.