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

Opioid analgesic and antidepressant use during pregnancy and the risk of spontaneous preterm birth: A nested case-control study

BACKGROUND

Given the high prevalence of both mental health and acute pain conditions during pregnancy, use of antidepressants and analgesic opioids in this period is widespread. Whether single and combined use of these medications is associated with spontaneous preterm birth (sPTB) remains unclear.

OBJECTIVES

To investigate the association between maternal prescription opioid and antidepressant medication exposures for co-occurring mental health and acute pain management, either alone or in combination, and sPTB.

METHODS

We used Tennessee Medicaid data (2007-2019) linked to birth certificates to conduct a nested case-control study among 15- to 44-year-old pregnant patients with singleton live births. Cases were identified as spontaneous live births between 24 and <37 gestational weeks using a validated birth certificate-based algorithm. We selected up to 10 controls per case, matched on estimated pregnancy start date and other factors. We identified analgesic opioid and antidepressant pharmacy fills to define medication exposures in the 60 days before index date (case delivery date) and categorised them as unexposed, opioid-only, antidepressant-only and combined exposure. We estimated odds ratios (OR) and 95% confidence intervals (CI) using conditional logistic regression, adjusting for confounders. We assessed the additive interaction between opioids and antidepressants by estimating relative excess risk due to interaction.

RESULTS

We identified 25,406 eligible cases of sPTB and 225,771 matched controls. Opioid-only and combined exposures were associated with higher odds of sPTB relative to unexposed (adjusted OR 1.29, 95% CI 1.23, 1.35 and 1.22, 95% CI 1.06, 1.40, respectively), while antidepressant-only exposure was not (1.04, 95% CI 0.96, 1.12). No additive interaction was identified for combined exposure.

CONCLUSIONS

Exposure to prescription opioids during pregnancy, but not antidepressants, was associated with increased relative odds of sPTB. Co-exposure to opioids and antidepressants did not elevate the odds of sPTB above what we observed for opioid-only exposure.

Maternal exposure to buprenorphine, but not methadone, during pregnancy reduces social play behavior across two generations of offspring

RATIONALE

The prevalence of newborns exposed to medications for opioid use disorder (MOUD), such as methadone or buprenorphine, during pregnancy is increasing. The opioid system plays a crucial role in regulating and shaping social behavior, and children prenatally exposed to opioids face an increased risk of developing behavioral problems. However, the impact of prenatal exposure to MOUD on offspring's social behavior during adolescence and adulthood, as well as potential intergenerational effects, remains largely unexplored.

OBJECTIVES

Our study employed a translationally relevant animal model to investigate how maternal (F0) exposure to MOUD during pregnancy affects social behavior in young and adult rats across the first (F1) and second (F2) generation of offspring.

METHODS

Female Sprague-Dawley rats were implanted with an osmotic minipump delivering methadone (10 mg/kg/day), buprenorphine (1 mg/kg/day), or sterile water, prior to mating with drug-naïve males. Adult F1 females were mated with treatment-matched F1 males to generate F2 offspring. We assessed social play behavior in juvenile offspring, and social interaction behavior in a three-chamber social interaction test in young adults of the F1 and F2 generations.

RESULTS

Maternal exposure to buprenorphine, but not methadone, during pregnancy reduced social play behavior in both F1 and F2 offspring, expressed by a reduced number of pounces and pins, which are the two most characteristic parameters of social play in rats. Adult social interactions were unaffected by prenatal MOUD exposure across both generations.

CONCLUSIONS

Maternal exposure to buprenorphine during pregnancy may have adverse effects on social play behavior across two generations of offspring.

Assessing the Eat, Sleep, Console model for neonatal abstinence syndrome management at a regional referral center

OBJECTIVE

We assessed the efficacy of the Eat, Sleep, Console (ESC) model for neonatal abstinence syndrome at a regional referral center by examining non-pharmacological treatments, parental presence, length of stay (LOS), and pharmacological therapy.

STUDY DESIGN

We retrospectively reviewed medical records from 2018 to 2020 to compare neonatal outcomes between the 12 months prior to 12 months post ESC implementation.

RESULT

A total of 71 neonates pre-ESC and 64 neonates post-ESC implementation were included. There were no statistical differences between pre-ESC vs. ESC periods for pharmacological therapy (34% vs. 27%, p = 0.36) or LOS (median: 5.0 vs. 5.5 days, p = 0.54). During the ESC period, 41% of examined 4-h periods had no parent/caregiver presence. Decreased parental presence associated with pharmacological treatment (p < 0.001).

CONCLUSION

At our hospital which serves a geographically dispersed patient population, ESC model implementation did not decrease pharmacological therapy rates or LOS. Parental/caregiver presence may be a factor in the ESC model producing maximal benefits.

Hypoglycaemia in non-diabetic pregnancy

Hypoglycaemia in non-diabetic pregnancy is rare, the majority of reported cases being due to insulinoma, acute fatty liver of pregnancy, malaria and inborn errors of metabolism. A case of hypoglycaemia in a woman with previous laparoscopic sleeve gastrectomy, and hypothalamic-pituitary-adrenal axis insufficiency in the setting of opioid dependence is presented. The timing of low interstitial glucose levels was atypical for late dumping syndrome following bariatric surgery, and a change in the woman's glucocorticoid replacement resulted in resolution of hypoglycaemic symptoms. The incidence of opioid dependence in pregnancy is increasing rapidly. Health professionals should be aware of the possibility of opioids causing hypothalamic-pituitary-adrenal axis insufficiency, and the additional mechanisms by which opioids may cause hypoglycaemia.

Delivery timing for the opioid-exposed infant

BACKGROUND

The prevalence of opioid use disorder and medication-assisted treatment in pregnancy is increasing. Compared with term infants, preterm infants have a lower incidence of neonatal opioid withdrawal syndrome. It is unknown whether early term delivery compared with full or late-term delivery decreases the risk of neonatal opioid withdrawal syndrome.

OBJECTIVE

This study aimed to compare the neonatal outcomes among opioid-exposed infants born in the early, full, and late-term periods.

STUDY DESIGN

This was a retrospective cohort study of opioid-exposed pregnancies delivering at a single center from 2010 to 2017 at ≥37 weeks gestation. Participants with multiple gestations or fetal anomalies were excluded. Maternal opioid exposure was defined as prescription (including medication-assisted treatment) or nonprescription opioid use or a positive urine drug screen in pregnancy for opiates. The primary outcome was a neonatal composite of respiratory distress syndrome, neonatal sepsis, neonatal seizures, hypoxic ischemic encephalopathy, jaundice requiring treatment, 5-minute Apgar <5, neonatal intensive care unit admission, neonatal opioid withdrawal syndrome, or neonatal death. The secondary outcomes included individual components of the primary outcome, birthweight, need for and length of neonatal opioid withdrawal syndrome treatment, length of hospital admission, and maximum Finnegan scores. Early (37-<39), full (39-<41), and late (41-<42 weeks) term groups were defined by the American College of Obstetricians and Gynecologists.

RESULTS

Of 399 infants, 136 (34.1%), 229 (57.4%), and 34 (8.5%) were born in the early, full, and late-term periods, respectively. Two hundred and seventy patients (67.7%) received medication-assisted treatment for opioid use disorder, and the baseline characteristics were similar in all the groups except for history of intranasal heroin use, positive urine toxicology screen for heroin or any opiates, and delivery indication (P<.05). The primary composite outcome occurred in 313 (78.4%) neonates, and 296 (74.2%) neonates had neonatal opioid withdrawal syndrome. More than half (219 [54.9%]) of opioid-exposed neonates were admitted to the neonatal intensive care unit, and 160 (40.1%) required pharmacologic neonatal opioid withdrawal syndrome treatment for a mean duration of almost 3 weeks (19.0±16.1 days). There were no significant differences in the primary composite outcome, incidence of neonatal opioid withdrawal syndrome, or other secondary outcomes (except birthweight) between neonates born in the early, full, or late-term periods.

CONCLUSION

Although neonatal morbidity was frequent among opioid-exposed neonates, the incidence and severity of neonatal opioid withdrawal syndrome or other neonatal outcomes were not different between neonates delivered in the early, full, and late-term periods, suggesting that opioid-exposed infants may not benefit from early term delivery.

Substance-related diagnosis type predicts the likelihood and co-occurrence of preterm and cesarean delivery

This article aimed to evaluate whether a substance-related diagnosis (SRD; i.e., alcohol, opioids, cannabis, stimulants, nicotine) predicts the likelihood and co-occurrence of preterm (20-37 weeks' gestation) and cesarean delivery.

This study reviewed electronic health record data on women (aged 18-44 years) who delivered a single live or stillbirth at ≥ 20 weeks of gestation from 2012 to 2019. Women with and without an SRD were matched on key demographic characteristics at a 1:1 ratio. Adjusting for covariates, odds ratios and 95% confidence intervals were calculated.

Of the 19,346 deliveries, a matched cohort of 2,158 deliveries was identified. Of these, 1,079 (50%) had an SRD, 280 (13%) had a preterm delivery, 833 (39%) had a cesarean delivery, and 166 (8%) had a co-occurring preterm and cesarean delivery. An SRD was significantly associated with preterm and cesarean delivery (AOR = 1.84 [95% CI, 1.41-2.39], p-value= <0.0001; AOR = 1.51 [95% CI, 1.23-1.85], p-value= <0.0001). An alcohol-related diagnosis (AOR = 1.82 [95% CI, 1.01-3.28], p-value= 0.0471), opioid-related diagnosis (AOR = 1.94 [95% CI, 1.26-2.98], p-value= 0.0027), stimulant-related diagnosis (AOR = 1.65 [95% CI, 1.11-2.45], p-value= 0.0142), and nicotine-related diagnosis (AOR = 1.54 [95% CI, 1.05-2.26], p-value= 0.0278) were associated with co-occurring preterm and cesarean delivery.

Pregnant women with an SRD experienced disproportionally higher odds of preterm and cesarean delivery compared to pregnant women without an SRD. Substance-type predicts the type of delivery outcome. An SRD in pregnant women should be identified early to reduce potential harm through intervention and treatment.

Perinatal Opioid Use Disorder Research, Race, and Racism: A Scoping Review

CONTEXT

Racial/ethnic inequities are well documented in both maternal-infant health and substance use disorder treatment outcomes.

OBJECTIVE

To systematically review research on maternal-infant dyads affected by opioid use disorder (OUD) to evaluate for racial/ethnic disparities in health utilization or outcomes and critically assess the reporting and inclusion of race/ethnicity data.

DATA SOURCES

Peer-reviewed literature in MEDLINE, Embase, and Web of Science from 2000 to 2020.

STUDY SELECTION

Research reporting health utilization and outcomes data on dyads affected by OUD during pregnancy through the infant's first birthday.

DATA EXTRACTION

We extracted data on race/ethnicity, study exposures/outcomes, how race/ethnicity data were analyzed, how authors discussed findings associated with race/ethnicity, and whether racism was mentioned as an explanation for findings.

RESULTS

Of 2023 articles reviewed, 152 quantitative and 17 qualitative studies were included. Among quantitative studies, 66% examined infant outcomes (n = 101). Three articles explicitly focused on evaluating racial/ethnic differences among dyads. Among quantitative studies, 112 mentioned race/ethnicity, 63 performed analyses assessing for differences between exposure groups, 27 identified racial/ethnic differences, 22 adjusted outcomes for race/ethnicity in multivariable analyses, and 11 presented adjusted models stratified by race/ethnicity. None of the qualitative studies addressed the role that race, ethnicity, or racism may have had on the presented themes.

CONCLUSIONS

Few studies were designed to evaluate racial/ethnic inequities among maternal-infant dyads affected by OUD. Data on race/ethnicity have been poorly reported in this literature. To achieve health equity across perinatal OUD, researchers should prioritize the inclusion of marginalized groups to better address the role that structural racism plays.

Risk factors for preterm birth among gravid individuals receiving buprenorphine for opioid use disorder

OBJECTIVE

Pregnancies complicated by opioid use disorder (OUD) are at an increased risk for preterm birth (PTB), defined as delivery <37 weeks gestation. Limited literature is available on prevalence and risk factors for PTB in pregnancies complicated by OUD maintained on buprenorphine Therefore, we sought to determine rate of PTB and risk factors for PTB in this population.

STUDY DESIGN

We performed a retrospective cohort study of pregnant individuals with singleton gestation receiving buprenorphine for OUD, who delivered at a tertiary academic medical center between 7/1/2013 and 6/30/2018. Individuals who had at least three visits in our co-located clinic were included in analysis. Patients were divided into 2 groups, those delivered <37 weeks gestation were included in preterm group, while patient delivered ≥ 37 weeks were included in term group. We defined "supplements to buprenorphine" to include any illicit drugs found on antepartum urine toxicology. Variables evaluated as potential risk factors for PTB included medical and infectious comorbidities as well as illicit polysubstance use.

RESULTS

The overall PTB rate in this cohort was 22.7% (115/507). There was a non-significant trend towards decrease in overall PTB and provider-initiated PTB rate over study period. No differences found in spontaneous PTB or PTB< 34 weeks. There were no differences in use of tobacco, alcohol, number of prenatal visits or gestational age when prenatal care started between those who delivered preterm compared to term. Individuals with PTB in the index pregnancy were more likely to have history of PTB compared to those with term delivery (73% vs 16%; P<.01). No medical or infectious comorbidity nor any specific supplement increased risk of PTB. Among individuals using 0, 1, 2, or 3 or more illicit supplements in addition to confirmed buprenorphine for OUD, the PTB rate was 27.4% (reference), 18.0% (P=0.09), 18.1% (P=0.44), and 15.8% (P=0.77), respectively.

CONCLUSION

The PTB rate among individuals using buprenorphine for OUD (22.7%) is higher than national average but lower than the reported PTB rate in individuals using methadone for MOUD.. No medical or infectious comorbidity or use of additional illicit substances increased the risk of PTB.

Outcomes of Neonates Exposed to Buprenorphine versus Methadone in Utero: A Systematic Review and Meta-Analysis of Safety in the Fetus and Neonate

We assessed the prevalence of neonatal abstinence syndrome (NAS) and fetal growth outcomes in neonates exposed to methadone compared to buprenorphine in utero. Three authors assessed the titles and abstracts of all potentially eligible studies. The selection criteria were randomized controlled trials and observational cohort studies from January 2000 to January 2020 which indexed and reported original data for occurrence of NAS and fetal growth outcomes in pregnant people who received methadone vs. buprenorphine treatment. The quality and possible bias of each study was assessed using the Cochrane-risk-of-bias tool. Data were pooled to compare the occurrence of NAS and fetal growth restriction among women who received methadone vs. buprenorphine treatment. Of the 106 articles screened, 1 randomized controlled trial and 5 observational cohort studies including 2041 pregnancies fulfilled the inclusion criteria. Buprenorphine is associated with less NAS and improved growth outcomes compared to methadone. (OR = 0.515; p-value < 0.001). Compared to methadone, buprenorphine is associated with less adverse neonatal outcomes in terms of gestational age at birth, birthweight, and head circumference. With the prevalence of NAS continuing to rise, this study adds to the expanding academic research aimed at creating safer treatment protocols.

Opioid Use Disorder and Perinatal Outcomes

OBJECTIVES

Evidence on the perinatal health of mother-infant dyads affected by opioids is limited. Elevated risks of opioid-related harms for people with opioid use disorder (OUD) increase the urgency to identify protective factors for mothers and infants. Our objectives were to determine perinatal outcomes after an OUD diagnosis and associations between opioid agonist treatment and birth outcomes.

METHODS

We conducted a population-based retrospective study among all women with diagnosed OUD before delivery and within the puerperium period in British Columbia, Canada, between 2000 and 2019 from provincial health administrative data. Controlling for demographic and clinical characteristics, we determined associations of opioid agonist treatment on birth weight, gestational age, infant disorders related to gestational age and birth weight, and neonatal abstinence syndrome via logistic regression.

RESULTS

The population included 4574 women and 6720 live births. Incidence of perinatal OUD increased from 166 in 2000 to 513 in 2019. Compared with discontinuing opioid agonist treatment during pregnancy, continuous opioid agonist treatment reduced odds of preterm birth (adjusted odds ratio: 0.6; 95% confidence interval: 0.4-0.8) and low birth weight (adjusted odds ratio: 0.4; 95% confidence interval: 0.2-0.7). Treatment with buprenorphine-naloxone (compared with methadone) reduced odds of each outcome including neonatal abstinence syndrome (adjusted odds ratio: 0.6; 95% confidence interval: 0.4-0.9).

CONCLUSIONS

Perinatal OUD in British Columbia tripled in incidence over a 20-year period. Sustained opioid agonist treatment during pregnancy reduced the risk of adverse birth outcomes, highlighting the need for expanded services, including opioid agonist treatment to support mothers and infants.

Marijuana use in opioid exposed pregnancy increases risk of preterm birth

BACKGROUND

The prevalence of opioid use disorder has increased across the United States, but the rural population of Appalachia has been disproportionately impacted. Concurrently, the slow, but steady progress in the legalization of marijuana may be affecting perception of marijuana use in pregnancy. However, marijuana use in pregnancy has been associated with adverse perinatal outcomes. Concomitant use of opioids and marijuana in pregnancy has not been evaluated.

OBJECTIVE

The primary aim of the study was to evaluate the association between confirmed marijuana use in late pregnancy and preterm birth in opioid-exposed pregnancies.

METHODOLOGY

A retrospective chart review was conducted that included all births from July 2011 to June 2016 from 6 delivery hospitals in South-Central Appalachia. Out of 18,732 births, 2368 singleton pregnancies indicated opioid use and met remaining inclusion criteria, with 108 of these mothers testing positive for marijuana at delivery. Independent sample t-test and Chi-Square analyses compared marijuana and non-marijuana exposed groups on maternal and neonatal outcomes. Regression analyses controlled for confounding variables in predicting neonatal abstinence syndrome (NAS), NICU admission, preterm birth, small for gestational age, and low birth weight outcomes as shown in Table 1.

RESULTS

Neonates born to marijuana-positive women in opioid-exposed pregnancy were more likely to be born preterm, small for gestational age, have low birth weight, and be admitted to NICU. After statistically controlling for parity, marital status, tobacco and benzodiazepine use, preterm birth and low birth weight remained statistically significant with aOR of 2.35 (1.30-4.24) and 2.01 (1.18-3.44), respectively.

CONCLUSIONS

Maternal use of marijuana in any opioid-exposed pregnancy may increase risk of preterm birth and low-birth weight infants. Prospective studies need to examine the dose and timing of marijuana and opioid use in pregnancy to better delineate perinatal effects. Nonetheless, pregnant women using opioids, including recommended medication assisted treatment for opioid use disorder, should be educated about the risks of concurrent marijuana use during pregnancy and may need to be counseled to abstain from marijuana use during pregnancy for an optimal outcome.

Explaining differential effects of medication for opioid use disorder using a novel approach incorporating mediating variables

BACKGROUND AND AIMS

A recent study found that homeless individuals with opioid use disorder (OUD) had a lower risk of relapse on extended-release naltrexone (XR-NTX) versus buprenorphine-naloxone (BUP-NX), whereas non-homeless individuals had a lower risk of relapse on BUP-NX. This secondary study examined differences in mediation pathways to medication effect between homeless and non-homeless participants.

DESIGN

Secondary analysis of an open-label randomized controlled, 24-week comparative effectiveness trial, 2014-17.

SETTING

Eight community addiction treatment programs in the United States.

PARTICIPANTS

English-speaking adults with DSM-5 OUD, recruited during inpatient admission (n = 570).

INTERVENTION(S)

Randomization to monthly injection of XR-NTX or daily sublingual BUP-NX.

MEASUREMENTS(S)

Mediation analysis estimated the direct effect of XR-NTX versus BUP-NX on relapse and indirect effect through mediators of medication adherence, use of illicit opioids, depressive symptoms and pain, separately by homeless status.

FINDINGS

For the homeless subgroup, the protective indirect path contributed a 3.4 percentage point reduced risk of relapse [95% confidence interval (CI) = -12.0, 5.3] comparing XR-NTX to BUP-NX (explaining 21% of the total effect). For the non-homeless subgroup, the indirect path contributed a 9.4 percentage point increased risk of relapse (95% CI = 3.1, 15.7) comparing XR-NTX to BUP-NX (explaining 57% of the total effect).

CONCLUSIONS

A novel approach to mediation analysis shows that much of the difference in medication effectiveness (extended-release naltrexone versus buprenorphine-naloxone) on opioid relapse among non-homeless adults with opioid use disorder appears to be explained by mediators of adherence, illicit opioid use, depressive symptoms and pain.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Integrated Review of the Assessment of Newborns With Neonatal Abstinence Syndrome

OBJECTIVE

To critically review and summarize current knowledge regarding the assessment of newborns with neonatal abstinence syndrome (NAS).

DATA SOURCES

We searched the following databases for articles on the assessment of newborns with NAS that were published in English between January 2014 and June 2020: PubMed, CINAHL, and PsycINFO. Keywords and Medical Subject Heading terms used to identify relevant research articles included neonatal abstinence syndrome; Finnegan Scale; eat, sleep, console; epigenetics; genetics; pharmacokinetics; and measurement. We independently reviewed articles for inclusion.

STUDY SELECTION

We retrieved 435 articles through database searches and 17 through manual reference searches; 31 articles are included in the final review. Excluded articles were duplicates, not relevant to NAS, qualitative studies, and/or of low quality.

DATA EXTRACTION

We used the methodology of Whittemore and Knafl to guide this integrative review. We extracted and organized data under the following headings: author, year and country, purpose, study design, participants, measurement, biomarker (if applicable), results, limitations, recommendations, and intervention.

DATA SYNTHESIS

The Finnegan Neonatal Abstinence Scale is the most widely used instrument to measure symptoms of NAS in newborns, although it is very subjective. Recently, there has been a transition from the Finnegan Neonatal Abstinence Scale to the eat, sleep, console method, which consists of structured assessment and intervention and has been shown to decrease length of hospital stay and total opioid treatment dose. Researchers examined biomarkers of NAS, including genetic markers and autonomic nervous system responses, on the variation in incidence and differential severity of NAS. In the included articles, women with opioid use disorder who were treated with naltrexone during pregnancy gave birth to newborns without NAS diagnoses. However, most women who were treated with buprenorphine gave birth to newborns with NAS diagnoses.

CONCLUSION

NAS negatively affects newborns in a multitude of ways, and the objective assessment and measurement of the newborn's response to withdrawal remains understudied and needs further investigation.

Non-pharmacological care for opioid withdrawal in newborns

BACKGROUND

The prevalence of substance use, both prescribed and non-prescribed, is increasing in many areas of the world. Substance use by women of childbearing age contributes to increasing rates of neonatal abstinence syndrome (NAS). Neonatal opioid withdrawal syndrome (NOWS) is a newer term describing the subset of NAS related to opioid exposure. Non-pharmacological care is the first-line treatment for substance withdrawal in newborns. Despite the widespread use of non-pharmacological care to mitigate symptoms of NAS, there is not an established definition of, and standard for, non-pharmacological care practices in this population. Evaluation of safety and efficacy of non-pharmacological practices could provide clear guidance for clinical practice.

OBJECTIVES

To evaluate the safety and efficacy of non-pharmacological treatment of infants at risk for, or having symptoms consistent with, opioid withdrawal on the length of hospitalization and use of pharmacological treatment for symptom management. Comparison 1: in infants at risk for, or having early symptoms consistent with, opioid withdrawal, does non-pharmacological treatment reduce the length of hospitalization and use of pharmacological treatment? Comparison 2: in infants receiving pharmacological treatment for symptoms consistent with opioid withdrawal, does concurrent non-pharmacological treatment reduce duration of pharmacological treatment, maximum and cumulative doses of opioid medication, and length of hospitalization?

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search CENTRAL (2019, Issue 10); Ovid MEDLINE; and CINAHL on 11 October 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomized controlled trials (RCTs), quasi-RCTs, and cluster trials.

SELECTION CRITERIA

We included trials comparing single or bundled non-pharmacological interventions to no non-pharmacological treatment or different single or bundled non-pharmacological interventions. We assessed non-pharmacological interventions independently and in combination based on sufficient similarity in population, intervention, and comparison groups studied. We categorized non-pharmacological interventions as: modifying environmental stimulation, feeding practices, and support of the mother-infant dyad. We presented non-randomized studies identified in the search process narratively.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence. Primary outcomes in infants at risk for, or having early symptoms consistent with, opioid withdrawal included length of hospitalization and pharmacological treatment with one or more doses of opioid or sedative medication. Primary outcomes in infants receiving opioid treatment for symptoms consistent with opioid withdrawal included length of hospitalization, length of pharmacological treatment with opioid or sedative medication, and maximum and cumulative doses of opioid medication.

MAIN RESULTS

We identified six RCTs (353 infants) in which infants at risk for, or having symptoms consistent with, opioid withdrawal participated between 1975 and 2018. We identified no RCTs in which infants receiving opioid treatment for symptoms consistent with opioid withdrawal participated. The certainty of evidence for all outcomes was very low to low. We also identified and excluded 34 non-randomized studies published between 2005 and 2018, including 29 in which infants at risk for, or having symptoms consistent with, opioid withdrawal participated and five in which infants receiving opioid treatment for symptoms consistent with opioid withdrawal participated. We identified seven preregistered interventional clinical trials that may qualify for inclusion at review update when complete. Of the six RCTs, four studies assessed modifying environmental stimulation in the form of a mechanical rocking bed, prone positioning, non-oscillating waterbed, or a low-stimulation nursery; one study assessed feeding practices (comparing 24 kcal/oz to 20 kcal/oz formula); and one study assessed support of the maternal-infant dyad (tailored breastfeeding support). There was no evidence of a difference in length of hospitalization in the one study that assessed modifying environmental stimulation (mean difference [MD) -1 day, 95% confidence interval [CI) -2.82 to 0.82; 30 infants; very low-certainty evidence) and the one study of support of the maternal-infant dyad (MD -8.9 days, 95% CI -19.84 to 2.04; 14 infants; very low-certainty evidence). No studies of feeding practices evaluated the length of hospitalization. There was no evidence of a difference in use of pharmacological treatment in three studies of modifying environmental stimulation (typical risk ratio [RR) 1.00, 95% CI 0.86 to 1.16; 92 infants; low-certainty evidence), one study of feeding practices (RR 0.92, 95% CI 0.63 to 1.33; 49 infants; very low-certainty evidence), and one study of support of the maternal-infant dyad (RR 0.50, 95% CI 0.13 to 1.90; 14 infants; very low-certainty evidence). Reported secondary outcomes included neonatal intensive care unit (NICU) admission, days to regain birth weight, and weight nadir. One study of support of the maternal-infant dyad reported NICU admission (RR 0.50, 95% CI 0.13 to 1.90; 14 infants; very low-certainty evidence). One study of feeding practices reported days to regain birth weight (MD 1.10 days, 95% CI 2.76 to 0.56; 46 infants; very low-certainty evidence). One study that assessed modifying environmental stimulation reported weight nadir (MD -0.28, 95% CI -1.15 to 0.59; 194 infants; very low-certainty evidence) and one study of feeding practices reported weight nadir (MD -0.8, 95% CI -2.24 to 0.64; 46 infants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

We are uncertain whether non-pharmacological care for opioid withdrawal in newborns affects important clinical outcomes including length of hospitalization and use of pharmacological treatment based on the six included studies. The outcomes identified for this review were of very low- to low-certainty evidence. Combined analysis was limited by heterogeneity in study design and intervention definitions as well as the number of studies. Many prespecified outcomes were not reported. Although caregivers are encouraged by experts to optimize non-pharmacological care for opioid withdrawal in newborns prior to initiating pharmacological care, we do not have sufficient evidence to inform specific clinical practices. Larger well-designed studies are needed to determine the effect of non-pharmacological care for opioid withdrawal in newborns.

Prenatal exposure to methadone or buprenorphine impairs cognitive performance in young adult rats

BACKGROUND

Concerns have been raised about the use of opioid maintenance treatment (OMT) during pregnancy and negative effects for the offspring. While neonatal outcomes and short-term effects are relatively well described, studies examining long-term effects in adolescents and adults are absent. The aim of the present study was to examine effects on learning and memory in young adult rats prenatally exposed to methadone or buprenorphine.

METHODS

Female rats were implanted with a 28-day osmotic minipump delivering methadone (10 mg/kg/day), buprenorphine (1 mg/kg/day) or vehicle 5 days prior to mating. To examine possible effects on cognitive functioning, young adult offspring were included in three different behavioral tests that examine recognition memory, nonspatial, and spatial learning and memory. In addition, offspring growth and maternal behavior after birh were investigated.

RESULTS

Prenatal exposure to methadone or buprenorphine caused impaired recognition memory and nonspatial reference learning and memory in young adult rats compared with the vehicle-treated group. Methadone-exposed offspring, but not the buprenorphine-exposed, also showed reduced long-term spatial memory. We did not observe any changes in maternal behavior or offspring growth after prenatal exposure to methadone or buprenorphine, suggesting that the impaired cognitive functioning is due to the opioid exposure rather than reduced maternal caregiving.

CONCLUSION

The present findings of long-term cognitive impairments in methadone- and buprenorphine-exposed offspring points to a negative impact of OMT on neurobiological development.

Mediation analysis for estimating cardioprotection of longitudinal RAS inhibition beyond lowering blood pressure and albuminuria in type 1 diabetes

PURPOSE

We assessed the extent of cardiovascular benefit of renin-angiotensin system (RAS) inhibition beyond lowering blood pressure (BP) and albuminuria in type 1 diabetes (T1D).

METHODS

This cohort study included 605 T1D participants from the Pittsburgh Epidemiology of Diabetes Complications study without baseline coronary artery disease (CAD). Participant follow-up extended through 25 years. We implemented marginal structural models to estimate total effect of and controlled direct effect by isolating the role of BP or albuminuria in mediating the relation between RAS inhibitors and CAD.

RESULTS

Total effect of longitudinal RAS inhibition treatment was associated with 38% decreased CAD risk (HR [95% CI]: 0.62 [0.23, 1.77]). The controlled direct effect of RAS inhibition was a 27% risk reduction (HR: 0.73 [0.20, 2.59]) when isolating the role of BP and 26% risk reduction (HR: 0.74 [0.16, 3.35]) when isolating the role of albuminuria. The mediation proportion for each 10 mm Hg systolic BP and each 1 log unit of albumin excretion rate were 34% and 37%, respectively.

CONCLUSION

Our findings suggest that BP regulation and albuminuria reduction can only partially explain cardiovascular benefit of RAS inhibition on CAD in T1D, supporting the assertion that RAS inhibitors provide additional cardioprotection beyond lowering BP and albuminuria.

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

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

High Accumulation of Methadone Compared with Buprenorphine in Fetal Rat Brain after Maternal Exposure

Experimental animal studies are valuable in revealing a causal relationship between prenatal exposure to opioid maintenance treatment (OMT) and subsequent effects; however, previous animal studies of OMT during pregnancy have been criticized for their lack of clinical relevance because of their use of high drug doses and the absence of pharmacokinetic data. Hence, the aim of this study was to determine blood and brain concentrations in rat dams, fetuses, and offspring after continuous maternal exposure to methadone or buprenorphine during gestation and to examine the offspring for neonatal outcomes and withdrawal symptoms. Female rats were implanted with a 28-day osmotic minipump delivering methadone (10 mg/kg per day), buprenorphine (1 mg/kg per day) or vehicle 5 days before mating. Continuous exposure to methadone or buprenorphine induced stable blood concentrations in the dams of 0.25 ± 0.02 µM and 5.65 ± 0.16 nM, respectively. The fetal brain concentration of methadone (1.89 ± 0.35 nmol/g) was twice as high as that in the maternal brain, whereas the fetal brain concentration of buprenorphine (20.02 ± 4.97 pmol/g) was one-third the maternal brain concentration. The opioids remained in the offspring brain several days after the exposure ceased. Offspring prenatally exposed to methadone, but not buprenorphine, displayed reduced body weight and length and increased corticosterone levels. No significant changes in ultrasonic vocalizations were revealed. Our data in rat fetuses and neonates indicate that OMT with buprenorphine may be a better choice than methadone during pregnancy. SIGNIFICANCE STATEMENT: Concern has been raised about the use of opioid maintenance treatment during pregnancy because of the important role of the endogenous opioid system in brain development. Here, we show that the methadone concentration in the fetal rat brain was twice as high as that in the maternal brain, whereas the buprenorphine concentration was one-third the maternal concentration. Furthermore, buprenorphine allowed more favorable birth outcomes, suggesting that buprenorphine may be a better choice during pregnancy.

Neonatal abstinence syndrome

Neonates exposed prenatally to opioids will often develop a collection of withdrawal signs known as neonatal abstinence syndrome (NAS). The incidence of NAS has substantially increased in recent years placing an increasing burden on the healthcare system. Traditional approaches to assessment and management have relied on symptom-based scoring tools and utilization of slowly decreasing doses of medication, though newer models of care focused on non-pharmacologic interventions and rooming-in have demonstrated promise in reducing length of hospital stay and medication usage. Data on long-term outcomes for both traditional and newer approaches to care of infants with NAS is limited and an important area of future research. This review will examine the history, incidence and pathophysiology of NAS. We will also review diagnostic screening approaches, scoring tools, differing management approaches and conclude with recommendations for continued work to improve the care of infants with NAS.