Methadone and buprenorphine for opioid dependence during pregnancy: a retrospective cohort study

Associations between Orofacial Clefting and Neonatal Abstinence Syndrome

Background:

Orofacial clefting (OFC) is the most common developmental craniofacial malformation, and causal etiologies largely remain unknown. The opioid crisis has led to a large proportion of infants recovering from neonatal abstinence syndrome (NAS) due to in-utero narcotics exposure. We sought to characterize the prevalence of OFC in infants with NAS.

Methods:

This cohort study analyzed live births at our institution from 2013 to 2017 to identify any association between OFC and NAS.

Results:

Prevalence of OFC was 6.79 and 1.63 (per 1,000 live births) in the NAS and general population, respectively. Odds ratios for NAS patients having developed OFC, isolated cleft palate, isolated cleft lip, and combined cleft lip and palate compared with the general population were found to be 4.18 (P = 0.001), 5.92 (P = 0.001), 3.79 (P = 0.05), and 2.94 (P = 0.35), respectively. Analyses performed comparing the NAS and general populations to control for potential confounding variables influencing the NAS population yielded no significant differences with exception of in-utero exposure to physician prescribed opioids.

Conclusions:

Prevalence of OFC in infants with NAS was higher than the general live birth population. Isolated cleft palate and isolated cleft lip, specifically, were significantly more prevalent in NAS patients compared with the general population and were associated with in-utero opioid exposure.

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.

Barriers to accessing treatment for pregnant women with opioid use disorder in Appalachian states

Background and aims: Opioid agonist therapies (OATs) are highly effective treatments for opioid use disorders (OUDs), especially for pregnant women; thus, improving access to OAT is an urgent public policy goal. Our objective was to determine if insurance and pregnancy status were barriers to obtaining access to OAT in 4 Appalachian states disproportionately impacted by the opioid epidemic. Methods: Between April and May 2017, we conducted phone surveys of OAT providers, opioid treatment programs (OTPs), and outpatient buprenorphine providers, in Kentucky, North Carolina, Tennessee, and West Virginia. Survey response rates were 59%. Logistic models for dichotomous outcomes (e.g., patient acceptance) and negative binomial models were created for count variables (e.g., wait time), overall and for pregnant women. Results: The majority of OAT providers were accepting new patients; however, providers were less likely to treat pregnant women (91% vs. 75%; p < .01). OTPs were more likely to accept new patients than waivered buprenorphine providers (97% vs. 83%; p = .01); rates of accepting pregnant patients were lower in both (91% and 53%; p < .01). OTPs and buprenorphine providers accepted cash payments for services at high rates (OTP: 100%; buprenorphine: 89.4%; p < .01); Medicaid and private insurance were accepted at lower rates. In adjusted models, providers were less likely to accept pregnant women if they took any insurance (adjusted odds ratio [aOR] = 0.15, 95% confidence interval [CI]: 0.03-0.68) or were a buprenorphine provider (aOR = 0.09, 95% CI: 0.02-0.37). Conclusions: We found that OAT providers frequently did not accept any insurance and frequently did not treat pregnant women in an area of the country disproportionately affected by the opioid epidemic. Policymakers could prioritize improvements in provider training (e.g., training of obstetricians to become buprenorphine prescribers) as a means to enhance access to pregnant women or enhancing reimbursement rates as a means of improving insurance acceptance for OAT.

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.

The Role of Preterm Birth in the Association Between Opioid Maintenance Therapy and Neonatal Abstinence Syndrome

BACKGROUND

Pregnant women treated with methadone as opioid maintenance therapy are more likely than women treated with buprenorphine to deliver preterm. Preterm birth is associated with less risk of neonatal abstinence syndrome (NAS). We sought to assess the role of preterm birth as a mediator of the relationship between in utero exposure to methadone and NAS compared with buprenorphine.

METHODS

We studied 716 women receiving methadone or buprenorphine and delivering liveborn infants at Magee-Womens Hospital, Pittsburgh, Pennsylvania (2013-15). We implemented inverse probability weighted marginal structural models to isolate the role of preterm birth (<37 weeks' gestation). Weights accounted for confounding by maternal age, race, insurance, parity, delivery year, marital, employment, hepatitis C, and smoking status.

RESULTS

Approximately 57% of the cohort were treated with methadone. Preterm birth was more common in methadone-exposed pregnancies (25% versus 14%). The incidence of NAS treatment was higher in methadone compared with buprenorphine-exposed infants (65% vs 49%), and term compared with preterm births (64% vs 36%). For every 100 infants liveborn to mothers treated for opioid dependence, there were 13 excess cases of NAS among infants exposed to methadone compared with buprenorphine (adjusted risk difference [RD] 13.3, 95% confidence interval [CI] 5.7, 20.9). Among term births, this increased to 17 excess cases of NAS in methadone- compared with buprenorphine-exposed (RD 16.7, 95% CI 9.3, 24.0).

CONCLUSION

The further increased risk of NAS associated with methadone use vs buprenorphine in term deliveries emphasises the utility of buprenorphine in clinical settings aimed at decreasing NAS.

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.

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.

Predictors of treatment retention in postpartum women prescribed buprenorphine during pregnancy

AIM

To determine variables related to treatment retention in women six and twelve months postpartum that were in medication treatment using buprenorphine during pregnancy.

METHODS

This retrospective cohort study of 190 maternal-infant dyads exposed to buprenorphine during pregnancy examines rates of treatment retention at six and twelve months postpartum and also analyzes a variety of potential predictors of treatment retention including illicit drug use in the third trimester, delayed entry into medication treatment and co-occurring mental health diagnoses requiring prescription medication.

RESULTS

At 12months postpartum, women appeared more likely to remain in medication treatment if they entered treatment early in pregnancy (defined as either being in treatment at the time of conception, p=0.001, or entering medication treatment prior to 13weeks gestation, p=0.037). Being prescribed an antidepressant medication during the third trimester was also associated with enhanced treatment retention at six months postpartum (p=0.005). At both six and twelve months postpartum, the use of illicit drugs (including opioids, cocaine and benzodiazepines) during the third trimester was negatively correlated with treatment retention (p=0.012 and p<0.001, respectively).

CONCLUSIONS

Early access to medication treatment is associated with treatment retention in women prescribed buprenorphine during pregnancy. This has important public health implications as access to treatment is limited in many parts of the country and many women are only able to obtain treatment after becoming pregnant. Being prescribed an antidepressant medication during pregnancy may enhance treatment retention, supporting the work of previous authors.

Sex and gender differences in substance use disorders

The gender gap in substance use disorders (SUDs), characterized by greater prevalence in men, is narrowing, highlighting the importance of understanding sex and gender differences in SUD etiology and maintenance. In this critical review, we provide an overview of sex/gender differences in the biology, epidemiology and treatment of SUDs. Biological sex differences are evident across an array of systems, including brain structure and function, endocrine function, and metabolic function. Gender (i.e., environmentally and socioculturally defined roles for men and women) also contributes to the initiation and course of substance use and SUDs. Adverse medical, psychiatric, and functional consequences associated with SUDs are often more severe in women. However, men and women do not substantively differ with respect to SUD treatment outcomes. Although several trends are beginning to emerge in the literature, findings on sex and gender differences in SUDs are complicated by the interacting contributions of biological and environmental factors. Future research is needed to further elucidate sex and gender differences, especially focusing on hormonal factors in SUD course and treatment outcomes; research translating findings between animal and human models; and gender differences in understudied populations, such as those with co-occurring psychiatric disorders and gender-specific populations, such as pregnant women.

Maternal and infant outcomes following third trimester exposure to marijuana in opioid dependent pregnant women maintained on buprenorphine

BACKGROUND

To determine whether maternal and infant outcomes are associated with exposure to marijuana during the third trimester in a population of opioid dependent pregnant women maintained on buprenorphine.

METHODS

This retrospective cohort study of 191 maternal-infant dyads exposed to buprenorphine during pregnancy examines a variety of variables including gestational age, birthweight, method of delivery, Apgar scores at one and five minutes, duration of infant hospital stay, peak neonatal abstinence syndrome (NAS) score, duration of NAS and incidence of pharmacologic treatment of NAS in infants exposed to marijuana during the third trimester as compared to infants not exposed to marijuana during the third trimester.

RESULTS

Analyses failed to support any significant relationship between marijuana use in the third trimester and a variety of maternal and infant outcomes. Two important variables - the likelihood of requiring pharmacologic treatment for NAS (27.6% in marijuana exposed infants vs. 15.7% in non-marijuana exposed infants, p=0.066) and the duration of infant hospital stay (7.7days in marijuana exposed infants vs. 6.6days in non-exposed infants, p=0.053) trended toward significance.

CONCLUSIONS

Preliminary results indicate that marijuana exposure in the third trimester does not complicate the pregnancy or the delivery process. However, the severity of the infant withdrawal syndrome in the immediate postnatal period may be impacted by marijuana exposure. Because previous study of prenatal marijuana exposure has yielded mixed results, further analysis is needed to determine whether these findings are indeed significant.

A Retrospective Cohort Study of Birth Outcomes in Neonates Exposed to Naltrexone in Utero: A Comparison with Methadone-, Buprenorphine- and Non-opioid-Exposed Neonates

BACKGROUND

Naltrexone may provide a suitable alternative to methadone and buprenorphine in the treatment of pregnant opioid-dependent women; however, little is known about its effects on neonatal morbidity and mortality.

OBJECTIVE

The aim was to evaluate the health of neonates exposed to naltrexone in utero, and compare it with outcomes in neonates exposed to methadone or buprenorphine and a non-exposed control group.

METHODS

Sequential cohorts of Western Australian (WA) opioid-dependent women treated with implant naltrexone, oral methadone or sublingual buprenorphine were identified via records from a drug and alcohol clinic (Subiaco, WA) for naltrexone and state prescribing records for methadone and buprenorphine. A control cohort of non-opioid-dependent women was obtained from the WA electoral roll. Identifying information and treatment records for these women were linked against the Midwife Notification System records to identify exposed offspring born between 2001 and 2011. Birth characteristics, congenital anomalies and perinatal mortality for all neonates were extracted from state records.

RESULTS

The birth characteristics of naltrexone-exposed neonates (n = 68) were superior to methadone-exposed neonates (n = 199) in terms of birth size (birth weight, head circumference and length), hospital length of stay (5.5 vs. 11.3 days), and rates of neonatal abstinence syndrome (NAS) (7.5 vs. 51.5%). Naltrexone-exposed neonates were generally not significantly different to buprenorphine-exposed neonates (n = 124), with the exception of significantly lower rates of NAS (7.5 vs. 41.8%) and shorter hospital length of stay (5.5 vs. 8.0 days) in naltrexone-exposed neonates. Compared with the control group of neonates (n = 569), naltrexone-exposed neonates were not significantly different in terms of overall rates of congenital anomalies, stillbirths and neonatal mortality; however, they were significantly smaller (3137.1 vs. 3378.0 g), spent more time in hospital following birth (5.5 vs. 4.3 days) and had higher rates of NAS (7.5 vs. 0.2%). Exposure of neonates to prenatal methadone was associated with a high incidence of neonatal mortality (2.0 vs. 0.2 per 100 live births) and congenital anomalies (10.6 vs. 4.4 per 100 births) compared with the control group. Rates of neonatal mortality and congenital abnormalities in buprenorphine-exposed neonates were not significantly different to the control group.

CONCLUSIONS

The use of implant naltrexone during pregnancy was not associated with higher rates of negative birth outcomes compared with methadone- and buprenorphine-exposed neonates. Significantly, naltrexone and buprenorphine were not associated with the high rates of neonatal mortality or congenital anomalies seen in methadone-exposed neonates.

Methadone, Buprenorphine, and Naltrexone for the Treatment of Opioid Use Disorder in Pregnant Women

Pregnant women with opioid use disorder can be treated with methadone, buprenorphine, or naltrexone to reduce opioid use and improve retention to treatment. In this review, we compare the pregnancy outcomes of methadone, buprenorphine, and naltrexone in clinical trials and discuss the potential behavioral and developmental effects of these agents seen in offspring in animal studies. Important clinical considerations in the management of opioid use disorder in pregnant women and their infants are also discussed. Outside of pregnancy, buprenorphine is used in combination with naloxone to reduce opioid abuse and diversion. During pregnancy, however, the use of buprenorphine as a single agent is preferred to prevent prenatal naloxone exposure. Both methadone and buprenorphine are widely used to treat opioid use disorder; however, compared with methadone, buprenorphine is associated with shorter treatment duration, less medication needed to treat neonatal abstinence syndrome (NAS) symptoms, and shorter hospitalizations for neonates. Despite being the standard of care, medication-assisted treatment with methadone or buprenorphine is still underused, making it apparent that more options are necessary. Naltrexone is not a first-line treatment primarily because both detoxification and an opioid-free period are required. More research is needed to determine naltrexone safety and benefits in pregnant women. Animal studies suggest that changes in pain sensitivity, developmental processes, and behavioral responses may occur in children born to mothers receiving methadone, buprenorphine, or naltrexone and is an area that warrants future studies.

Maternal Use of Opioids During Pregnancy and Congenital Malformations: A Systematic Review

CONTEXT

Opioid use and abuse have increased dramatically in recent years, particularly among women.

OBJECTIVES

We conducted a systematic review to evaluate the association between prenatal opioid use and congenital malformations.

DATA SOURCES

We searched Medline and Embase for studies published from 1946 to 2016 and reviewed reference lists to identify additional relevant studies.

STUDY SELECTION

We included studies that were full-text journal articles and reported the results of original epidemiologic research on prenatal opioid exposure and congenital malformations. We assessed study eligibility in multiple phases using a standardized, duplicate review process.

DATA EXTRACTION

Data on study characteristics, opioid exposure, timing of exposure during pregnancy, congenital malformations (collectively or as individual subtypes), length of follow-up, and main findings were extracted from eligible studies.

RESULTS

Of the 68 studies that met our inclusion criteria, 46 had an unexposed comparison group; of those, 30 performed statistical tests to measure associations between maternal opioid use during pregnancy and congenital malformations. Seventeen of these (10 of 12 case-control and 7 of 18 cohort studies) documented statistically significant positive associations. Among the case-control studies, associations with oral clefts and ventricular septal defects/atrial septal defects were the most frequently reported specific malformations. Among the cohort studies, clubfoot was the most frequently reported specific malformation.

LIMITATIONS

Variabilities in study design, poor study quality, and weaknesses with outcome and exposure measurement.

CONCLUSIONS

Uncertainty remains regarding the teratogenicity of opioids; a careful assessment of risks and benefits is warranted when considering opioid treatment for women of reproductive age.

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.

An overview of available drugs for management of opioid abuse during pregnancy

The prevalence of opioid abuse in the United States has been steadily increasing over the last several years among many major demographics, including pregnant women. Rise in prenatal opioid abuse has resulted in subsequent escalation of neonatal abstinence syndrome incidence, prompting the US Congress to pass the Protecting Our Infants Act of 2015. This act specifically calls for a critical review of current treatment options for prenatal opioid abuse which may ultimately lead to the development of better therapies and a decreased incidence of neonatal abstinence syndrome. Currently, the American College of Obstetricians and Gynecologists recommends methadone, buprenorphine, or buprenorphine/naloxone in the treatment of prenatal opioid abuse. In this review, each maintenance therapy treatment option is discussed and compared revealing inconsistencies in postpartum retention rates, effects on fetal development, and availability to patients due to restrictions in health care coverage. Although each of these treatment options reduces opioid abuse and potential negative outcomes for the fetus, the shortcomings of these drugs highlight the overarching need for an improved standard of care. Drug developers and lawmakers should consider that affordability, coverage by health insurance, and success in retention rates substantially impacts the decision of the patient and healthcare provider regarding utilization of a particular opioid maintenance therapy.

Buprenorphine compared with methadone to treat pregnant women with opioid use disorder: a systematic review and meta-analysis of safety in the mother, fetus and child

AIMS

To assess the safety of buprenorphine compared with methadone to treat pregnant women with opioid use disorder.

METHODS

We searched PubMed, Embase and the Cochrane Library from inception to February 2015 for randomized controlled trials (RCT) and observational cohort studies (OBS) that compared buprenorphine with methadone for treating opioid-dependent pregnant women. Two reviewers assessed independently the titles and abstracts of all search results and full texts of potentially eligible studies reporting original data for maternal/fetal/infant death, preterm birth, fetal growth outcomes, fetal/congenital anomalies, fetal/child neurodevelopment and/or maternal adverse events. We ascertained each study's risk of bias using validated instruments and assessed the strength of evidence for each outcome using established methods. We computed effect sizes using random-effects models for each outcome with two or more studies.

RESULTS

Three RCTs (n = 223) and 15 cohort OBSs (n = 1923) met inclusion criteria. In meta-analyses using unadjusted data and methadone as comparator, buprenorphine was associated with lower risk of preterm birth [RCT risk ratio (RR) = 0.40, 95% confidence interval (CI) = 0.18, 0.91; OBS RR = 0.67, 95% CI = 0.50, 0.90], greater birth weight [RCT weighted mean difference (WMD) = 277 g, 95% CI = 104, 450; OBS WMD = 265 g, 95% CI = 196, 335] and larger head circumference [RCT WMD = 0.90 cm, 95% CI = 0.14, 1.66; OBS WMD = 0.68 cm, 95% CI = 0.41, 0.94]. No treatment differences were observed for spontaneous fetal death, fetal/congenital anomalies and other fetal growth measures, although the power to detect such differences may be inadequate due to small sample sizes.

CONCLUSIONS

Moderately strong evidence indicates lower risk of preterm birth, greater birth weight and larger head circumference with buprenorphine treatment of maternal opioid use disorder during pregnancy compared with methadone treatment, and no greater harms.

A Swedish Population-based Study of Adverse Birth Outcomes among Pregnant Women Treated with Buprenorphine or Methadone: Preliminary Findings

BACKGROUND

Untreated opioid dependence in pregnant women is associated with adverse birth outcomes. Buprenorphine and methadone are options for opioid agonist medication-assisted treatment during pregnancy.

OBJECTIVE

The aim of this study was to describe adverse birth outcomes observed with buprenorphine or methadone treatment compared to the general population in Sweden.

METHODS

Pregnant women and their corresponding births during 2005–2011 were identified in the Swedish Medical Birth Register. Data on stillbirth, neonatal/infant death, mode of delivery, gestational age at birth, Apgar score, growth outcomes, neonatal abstinence syndrome, and congenital malformations were examined. Frequencies were compared using two-sided Fisher’s exact tests. Unadjusted estimates of birth outcomes for women treated with buprenorphine or methadone were compared to the registered general population.

RESULTS

A total of 746,257 pregnancies among 538,178 unique women resulted in 746,485 live births. Among the 194 women treated with buprenorphine (N = 176) or methadone (N = 52), no stillbirths or neonatal/infant deaths occurred. Neonatal abstinence syndrome developed in 23.3% and 38.5% of infants born to mothers treated with buprenorphine and methadone, respectively. The frequency of the selected adverse birth outcomes assessed in women treated with buprenorphine as compared to the general population was not significantly different. However, a significantly higher frequency of preterm birth and congenital malformations was observed in women treated with methadone as compared to the general population. Compared with the general population, methadone-treated women were significantly older than buprenorphine-treated women, and both treatment groups began prenatal care later, were more likely to smoke cigarettes, and did not cohabitate with the baby’s father.

CONCLUSIONS

An increased frequency of the selected adverse birth outcomes was not observed with buprenorphine treatment during pregnancy. Twofold increased frequency of preterm birth [2.21 (1.11, 4,41)] and congenital malformations [2.05 (1.08, 3.87)] was observed in the methadone group, which may be partly explained by older average maternal age and differences in other measured and unmeasured confounders.

Opioid use disorder during pregnancy in Tennessee: expediency vs. science

Methadone and buprenorphine are highly effective and commonly prescribed for the treatment of opioid use disorder. Both medications are also efficacious for the treatment of pregnant women with this disorder. In one third of states, however, Medicaid reimbursement will cover the cost of buprenorphine, but not methadone, to treat opioid use disorder in pregnant women. This commentary will explore the clinical and policy rational and consequences of this policy, with the opinion that this approach is guided by political expediency rather than sound clinical research. The commentary will focus on the pharmacological management of prescription opioid dependence during pregnancy in Tennessee, one of the states that restrict Medicaid coverage of pregnant women to buprenorphine. Tennessee is also relevant in that this state ranks second nationally in the rate of prescriptions written for opioid pain relievers; in contrast to injection opioid use in urban populations, opioid addiction in rural and southeastern regions of the US is characterized by use of non-injection prescription opioids. Until recently, most research-based recommendations for the management of opioid use disorder during pregnancy have derived from studies of women using opioids intravenously. The lack of research in non-injection opioid-using pregnant women may partially explain why policy rather than scientific evidence guides Medicaid reimbursement. It is hoped that future research in pregnant women addicted to prescription opioids will clarify which opioid addicted pregnant women have better outcomes with buprenorphine or methadone treatment and these findings, in turn, will inform Medicaid reimbursement.

Caring for pregnant opioid abusers in Vermont: A potential model for non-urban areas

Opioid addiction is no longer a primarily urban problem. As dependence on heroin and prescription pain relievers has become a significant issue in rural areas, the need for effective treatment of opioid-dependent pregnant women and their neonates has grown accordingly. In addition to the adverse perinatal outcomes associated with opioid addiction in pregnant women, the high costs of caring for these mothers and their babies motivate efforts to develop appropriate treatment models. We found that integration and coordination of services that promote maternal recovery and ability to parent are key requirements for treatment of opioid dependence during pregnancy. Unfortunately, lack of experience and resources makes such coordination a real challenge in rural areas. In this review, we discuss how we managed the challenges of developing a comprehensive program for treatment of opioid dependence during pregnancy. In addition, we outline our approach for facilitating the development of community-based programs to help these patients and families in rural regions of Vermont. Close relationships between our tertiary care center, local hospitals, community health care infrastructure, and legislators bolstered our efforts. In particular, appreciation for the severity and importance of the opioid-dependence problem in Vermont among health care providers and state legislators was paramount for our success in developing a state-wide treatment program. This approach can inform similar efforts in other rural regions of the United States, and has great potential to improve both access and quality of care for women struggling with opioid dependence.

Pharmacological Management of Opioid Use Disorder in Pregnant Women

Opioid misuse during pregnancy is associated with negative outcomes for both mother and fetus due not only to the physiological effects of the drug but also to the associated social, medical and mental health problems that accompany illicit drug use. An interdisciplinary approach to the treatment of opioid use disorder during pregnancy is most effective. Ideally, obstetric and substance use treatment are co-located and ancillary support services are readily available. Medication-assisted treatment with methadone or buprenorphine is intrinsic to evidence-based care for the opioid-using pregnant woman. Women who are not stabilized on an opioid maintenance medication experience high rates of relapse and worse outcomes. Methadone has been the mainstay of maintenance treatment for nearly 50 years, but recent research has found that both methadone and buprenorphine maintenance treatments significantly improve maternal, fetal and neonatal outcomes. Although methadone remains the current standard of care, the field is beginning to move towards buprenorphine maintenance as a first-line treatment for pregnant women with opioid use disorder, because of its greater availability and evidence of better neonatal outcomes than methadone. However, there is some evidence that treatment dropout may be greater with buprenorphine relative to methadone.