Opioid Use in Pregnant Women and Neonatal Abstinence Syndrome-A Review of the Literature

Evaluating the Association between Prenatal Care Visits and Adverse Perinatal Outcome in Pregnancies Complicated by Opioid Use Disorder

OBJECTIVE

 This study aimed to evaluate the association between number of prenatal care visits and adverse perinatal outcome among pregnant individuals with opioid use disorder (OUD).

STUDY DESIGN

 This is a retrospective cohort of singleton, nonanomalous pregnancies complicated by OUD that delivered from January 2015 to July 2020 at our academic medical center. Primary outcome was the presence of composite adverse perinatal outcome, defined as one or more of the following: stillbirth, placental abruption, perinatal death, neonatal respiratory distress syndrome, need for morphine treatment, and hyperbilirubinemia. Logistic and linear regression estimated the association between the number of prenatal care visits and the presence of adverse perinatal outcome. A Mann-Whitney U test evaluated the association between number of prenatal care visits and length of hospital stay for the neonate.

RESULTS

 A total of 185 patients were identified, of which 35 neonates required morphine treatment for neonatal opioid withdrawal syndrome. During pregnancy, most individuals were treated with buprenorphine 107 (57.8%), whereas 64 (34.6%) received methadone, 13 (7.0%) received no treatment, and 1 (0.5%) received naltrexone. The median number of prenatal care visits was 8 (interquartile range: 4-10). With each additional visit per 10 weeks of gestational age, the risk of adverse perinatal outcome decreased by 38% (95% confidence interval [CI]: 0.451-0.854). The need for neonatal intensive care and hyperbilirubinemia also significantly decreased with additional prenatal visits. Neonatal hospital stay decreased by a median of 2 days (95% CI: 1-4) for individuals who received more than the median of eight prenatal care visits.

CONCLUSION

 Pregnant individuals with OUD who attend fewer prenatal care visits experience more adverse perinatal outcome. Future research should focus on barriers to prenatal care and interventions to improve access in this high-risk population.

KEY POINTS

· Use of prenatal care affects newborn outcomes.. · More prenatal care shortens neonatal hospital stay.. · Prenatal care reduces certain adverse outcomes..

Maternal care behavior and physiology moderate offspring outcomes following gestational exposure to opioids

The opioid epidemic has resulted in a drastic increase in gestational exposure to opioids. Opioid-dependent pregnant women are typically prescribed medications for opioid use disorders ("MOUD"; e.g., buprenorphine [BUP]) to mitigate the harmful effects of abused opioids. However, the consequences of exposure to synthetic opioids, particularly BUP, during gestation on fetal neurodevelopment and long-term outcomes are poorly understood. Further, despite the known adverse effects of opioids on maternal care, many preclinical and clinical studies investigating the effects of gestational opioid exposure on offspring outcomes fail to report on maternal care behaviors. Considering that offspring outcomes are heavily dependent upon the quality of maternal care, it is important to evaluate the effects of gestational opioid exposure in the context of the mother-infant dyad. This review compares offspring outcomes after prenatal opioid exposure and after reduced maternal care and integrates this information to potentially identify common underlying mechanisms. We explore whether adverse outcomes after gestational BUP exposure are due to direct effects of opioids in utero, deficits in maternal care, or a combination of both factors. Finally, suggestions for improving preclinical models of prenatal opioid exposure are provided to promote more translational studies that can help to improve clinical outcomes for opioid-dependent mothers.

Embryonic exposure to fentanyl induces behavioral changes and neurotoxicity in zebrafish larvae

The use of fentanyl during pregnancy, whether by prescription or illicit use, may result in high blood levels that pose an early risk to fetal development. However, little is known regarding the neurotoxicity that might arise from excessive fentanyl exposure in growing organisms, particularly drug-related withdrawal symptoms. In this study, zebrafish embryos were exposed to fentanyl solutions (0.1, 1, and 5 mg/L) for 5 days post fertilization (dpf), followed by a 5-day recovery period, and then the larvae were evaluated for photomotor response, anxiety behavior, shoaling behavior, aggression, social preference, and sensitization behavior. Fentanyl solutions at 1 and 5 mg/L induced elevated anxiety, decreased social preference and aggressiveness, and behavioral sensitization in zebrafish larvae. The expression of genes revealed that embryonic exposure to fentanyl caused substantial alterations in neural activity (bdnf, c-fos) and neuronal development and plasticity (npas4a, egr1, btg2, ier2a, vgf). These results suggest that fentanyl exposure during embryonic development is neurotoxic, highlighting the importance of zebrafish as an aquatic species in research on the neurobehavioral effects of opioids in vertebrates.

Trajectories of Prescription Opioid Utilization During Pregnancy Among Prepregnancy Chronic Users and Risk of Neonatal Opioid Withdrawal Syndrome

Little is known about the impact of dose, duration, and timing of prenatal prescription opioid exposure on the risk of neonatal opioid withdrawal syndrome (NOWS). Using a cohort of 18,869 prepregnancy chronic opioid users nested within the 2000-2014 Medicaid Analytic eXtract, we assessed average opioid dosage within biweekly gestational age intervals, created group-based trajectory models, and evaluated the association between trajectory groups and NOWS risk. Women were grouped into 6 distinct opioid use trajectories which, based on observed patterns, were categorized as 1) continuous very low-dose use, 2) continuous low-dose use, 3) initial moderate-dose use with a gradual decrease to very low-dose/no use, 4) initial high-dose use with a gradual decrease to very low-dose use, 5) continuous moderate-dose use, and 6) continuous high-dose use. Absolute risk of NOWS per 1,000 infants was 7.7 for group 1 (reference group), 28.8 for group 2 (relative risk (RR) = 3.7, 95% confidence interval (CI): 2.8, 5.0), 16.5 for group 3 (RR = 2.1, 95% CI: 1.5, 3.1), 64.9 for group 4 (RR = 8.4, 95% CI: 5.6, 12.6), 77.3 for group 5 (RR = 10.0, 95% CI: 7.5, 13.5), and 172.4 for group 6 (RR = 22.4, 95% CI: 16.1, 31.2). Trajectory models-which capture information on dose, duration, and timing of exposure-are useful for gaining insight into clinically relevant groupings to evaluate the risk of prenatal opioid exposure.

The Aversion Function of the Limbic Dopaminergic Neurons and Their Roles in Functional Neurological Disorders

The Freudian theory of conversion suggested that the major symptoms of functional neurological disorders (FNDs) are due to internal conflicts at motivation, especially at the sex drive or libido. FND patients might behave properly at rewarding situations, but they do not know how to behave at aversive situations. Sex drive is the major source of dopamine (DA) release in the limbic area; however, the neural mechanism involved in FND is not clear. Dopaminergic (DAergic) neurons have been shown to play a key role in processing motivation-related information. Recently, DAergic neurons are found to be involved in reward-related prediction error, as well as the prediction of aversive information. Therefore, it is suggested that DA might change the rewarding reactions to aversive reactions at internal conflicts of FND. So DAergic neurons in the limbic areas might induce two major motivational functions: reward and aversion at internal conflicts. This article reviewed the recent advances on studies about DAergic neurons involved in aversive stimulus processing at internal conflicts and summarizes several neural pathways, including four limbic system brain regions, which are involved in the processing of aversion. Then the article discussed the vital function of these neural circuits in addictive behavior, depression treatment, and FNDs. In all, this review provided a prospect for future research on the aversion function of limbic system DA neurons and the therapy of FNDs.

Correlating Scores but Contrasting Outcomes for Eat Sleep Console Versus Modified Finnegan

OBJECTIVES

The Modified Finnegan Neonatal Abstinence Scoring System (M-FNASS) and the newer Eat, Sleep, and Console (ESC) model guide the clinical management of neonatal opioid withdrawal syndrome (NOWS). In this study, we evaluate how the M-FNASS and ESC model directly compare in inpatient practice. We hypothesized that ESC scores would correlate with M-FNASS scores, whereas ESC management would reduce health care use for infants with NOWS.

METHODS

In this retrospective cohort study, we compared management of infants with NOWS admitted to nursery settings. Epoch 1 was managed by using an M-FNASS algorithm. Epoch 2 was scored simultaneously with the M-FNASS and ESC model and managed by using the ESC approach. In the statistical analysis, we compared M-FNASS and ESC scores and outcomes between epochs.

RESULTS

A total of 158 infants provided 2101 scoring instances for analysis. Demographic characteristics were similar between epochs. ESC scores significantly correlated with overall M-FNASS scores and specific M-FNASS domains. Receiver operating characteristic (ROC) curve analysis revealed that an ESC score containing at least 1 "no" was best predicted by an M-FNASS cutoff value of 7.5 (sensitivity 0.84; specificity 0.70; area under the curve = 0.842). Length of stay (median 9.5 vs 5 days; P = .0002) and initiation (53% vs. 33%; P = .018) and duration of pharmacologic treatment (median 11 vs 7 days; P = .0042), as well as length of stay for infants who were pharmacologically treated (median 15 vs 10 days; P = .0002), were significantly reduced with ESC-based management after adjustment for covariates.

CONCLUSIONS

The ESC approach meaningfully correlates with the M-FNASS to detect NOWS. Management with the ESC approach continues to be associated with reduced health care use when compared with an M-FNASS approach, implying that the ESC approach may facilitate higher-value inpatient care.

Human Fetal Liver Metabolism of Oxycodone Is Mediated by CYP3A7

Oxycodone is an opioid analgesic that is commonly prescribed to pregnant women to treat moderate-to-severe pain. It has been shown to cross the placenta and distribute to the fetus. Oxycodone is mainly metabolized by CYP3A4 in the adult liver. Since CYP3A7 is abundantly expressed in the fetal liver and has overlapping substrate specificity with CYP3A4, we hypothesized that the fetal liver may significantly limit fetal exposure to oxycodone. This study showed that oxycodone is metabolized by CYP3A7 to noroxycodone in fetal liver microsomes (FLMs). The measured CYP3A7 expression was 191-409 pmol/mg protein in 14 FLMs, and an intersystem extrapolation factor (ISEF) for CYP3A7 was 0.016-0.066 in the panel of fetal livers using 6β-OH-testosterone formation as the probe reaction. Noroxycodone formation in the fetal liver was predicted from formation rate by recombinant CYP3A7, CYP3A7 expression level and the established ISEF value with average fold error of 1.25. Based on the intrinsic clearance of oxycodone measured in FLM, the fetal hepatic clearance (CLh) at term was predicted to be 495 (range: 66.4-936) μL/min, a value that is > 99% lower than the predicted adult liver CLh. The predicted fetal hepatic extraction ratio was 0.0019 (range: 0.00003-0.0036). These results suggest that fetal liver metabolism does not quantitatively contribute to the total systemic clearance of oxycodone in pregnant women nor does it provide a barrier for limiting fetal exposure to oxycodone. Additionally, since CYP3A7 forms noroxycodone, an inactive metabolite, the metabolism in the fetal liver is unlikely to affect fetal opioid activity.

Development and validation of the Neonatal Abstinence Syndrome Minimum Data Set (NAS-MDS): a systematic review, focus group discussion, and Delphi technique

OBJECTIVES

Neonatal abstinence syndrome (NAS) is a combination of symptoms in infants exposed to any variety of substances in utero. Information systems and registries help to collect information about these patients; however, there is always a deep gap between complete and accurate information to be collected, understood, and applied in the health care system; thus, defining a minimum data sets (MDS) as one of the primarily steps of designing a registry system is essential. The aim of this study was to develop an MDS of the registry for infants with NAS in Iran.

METHODS

This research is a descriptive cross-sectional study. In this study, three steps were carried out to develop the MDS including systematic review, Delphi technique, and focus group discussion. A systematic review was conducted in relevant databases to identify appropriate related data. In the second phase, a focus group discussion was used to classify the extracted data elements by contributing neonatologists. Finally, data elements were chosen through the decision Delphi technique in two distinct rounds. Collected data were analyzed using SPSS 22 (SPSS Inc., Chicago, IL).

RESULTS

By reviewing related papers and available NAS registries in other countries, 145 essential data elements were identified. They were classified into two main categories based on the eight experts' opinions including maternal with two sections and infant with two sections. After applying two rounds of Delphi technique, the final data elements for maternal and infant categories were 42 and 31, respectively. Thus, on completion of the survey, 73 data elements were approved.

CONCLUSION

The proposed MDS for NAS can help to store an accurate and comprehensive data, document medical records, integrate them with other information systems and registries, and communicate with other healthcare providers and healthcare centers. This MDS can contribute to the provision of high-quality care and better clinical decisions.

Marijuana and Opioid Use during Pregnancy: Using Zebrafish to Gain Understanding of Congenital Anomalies Caused by Drug Exposure during Development

Marijuana and opioid addictions have increased alarmingly in recent decades, especially in the United States, posing threats to society. When the drug user is a pregnant mother, there is a serious risk to the developing baby. Congenital anomalies are associated with prenatal exposure to marijuana and opioids. Here, we summarize the current data on the prevalence of marijuana and opioid use among the people of the United States, particularly pregnant mothers. We also summarize the current zebrafish studies used to model and understand the effects of these drug exposures during development and to understand the behavioral changes after exposure. Zebrafish experiments recapitulate the drug effects seen in human addicts and the birth defects seen in human babies prenatally exposed to marijuana and opioids. Zebrafish show great potential as an easy and inexpensive model for screening compounds for their ability to mitigate the drug effects, which could lead to new therapeutics.