Totality of the Evidence Suggests Prenatal Cannabis Exposure Does Not Lead to Cognitive Impairments: A Systematic and Critical Review

Vaporized Δ9-tetrahydrocannabinol exposure in utero has negative effects on attention in a dose- and sex-dependent manner

There has been an increasing use of cannabis during pregnancy in recent years. Studies have indicated that THC exposure in utero may increase the risk of attention deficits and memory impairments in adolescence. The goal of the present study is to investigate the effects of vaporized THC exposure during pregnancy on offspring memory and attention performance in early and late adolescence. Pregnant dams were exposed to vaporized THC (10 mg or 40 mg) daily from gestational day 2 until labor. Pups were given either a standard or a high-fat diet at weaning and tested in early and late adolescence in two memory tests, the Novel Object Recognition (NOR) test and the Morris Water Maze (MWM) test, and a test of attention, the Object-Based Attention (OBA) test. Rats exposed to low-dose THC showed significantly decreased object exploration in both the NOR and OBA tests, indicating decreased attention. Object exploration time in OBA was significantly lower in females than males. Additionally, post hoc analysis of MWM tests showed some differences in learning patterns for HD THC offspring in early adolescence, possibly due to diet interaction, but ultimate performance was not impacted. While there are existing studies examining prenatal exposure to THC in rodents, this is the first to our knowledge examining memory and attention in adolescence following vaporized THC exposure in utero, and we find indications that prenatal THC exposure may lead to attention deficits and altered memory performance.

Oral pre- and early postnatal cannabis exposure disinhibits ventral tegmental area dopamine neuron activity but does not influence cocaine preference in offspring in mice

Cannabis consumption has increased from 1.5% to 2.5% in Canada between 2012 and 2019. Clinical studies have indicated effects of prenatal cannabis exposure on birth weight, substance use, and neurodevelopmental disorders, but are confounded by several difficult to control variables. Animal models allow for examination of the mechanism of cannabis-induced changes in neurodevelopment and behavior, while controlling dose and timing. Several animal models of prenatal cannabis exposure exist which provide varying levels of construct validity, control of dose, and exposure to maternal stress. Using a voluntary oral consumption model, mouse dams received 5 mg/kg Δ9-tetrahydrocannabinol (THC) whole cannabis oil in peanut butter daily from gestational day 1 (GD1) to postnatal day 10 (PD10). At GD1, GD18, PD1, PD10, and PD15, maternal plasma was collected; pup brains were collected from GD18 onward. Pup brains had higher levels of THC and cannabidiol at each time point, each of which persisted in maternal plasma and pup brains past the end of treatment (PD15). Male and female adolescent offspring were examined for changes to ventral tegmental area (VTA) dopamine neuron activity and cocaine-seeking behavior. Prenatal and early postnatal (GD1-PD10) cannabis-exposed male, but not female mice had decreased gamma-aminobutyric acid (GABAergic) input, depolarized resting membrane potential, and increased spontaneous firing of VTA dopamine neurons. Cannabis-exposed offspring showed faster decay of N-methyl-D-aspartate (NMDA) currents in both sexes. However, no differences in cocaine-seeking behavior were noted. These data characterize a voluntary prenatal cannabis exposure model and demonstrates VTA dopamine neuronal activity is disinhibited in offspring.

Prenatal tobacco and tobacco-cannabis co-exposure: Relationship with attention and memory in middle childhood

We examined associations between prenatal tobacco exposure (with and without cannabis exposure) and children's performance on laboratory measures of sustained attention, attentional set shifting, and working memory in middle childhood (9-12 years of child age). Participants were recruited in the first trimester of pregnancy and oversampled for prenatal tobacco exposure; with a smaller sample (n = 133; n = 34 non-substance exposed, n = 37 exposed to tobacco only, n = 62 co-exposed) invited (oversampled for co-exposure) to participate in the middle-childhood assessment (M age = 10.6, SD = 0.77; 68% Black, 20% Hispanic). Results for sustained attention indicated lower attention (percent hits) at the first epoch for tobacco only exposed compared to non-exposed and co-exposed; a trend (p = .07) towards increases in impulsive responding across time (a total of 8 epochs) for tobacco exposed (with and without cannabis) compared to non-exposed children; and a significant association between higher number of cigarettes in the first trimester and greater increases in impulsive responding across epochs. However, children prenatally exposed to tobacco (with and without cannabis) demonstrated greater short-term memory compared to children not prenatally exposed, and this difference was driven by higher scores for children prenatally co-exposed to tobacco and cannabis compared to those who were non-exposed. Overall, results suggest that prenatal tobacco exposure, especially in the first trimester, may increase risk for impulsive responding on tasks requiring sustained attention, and that co-use of cannabis did not exacerbate these associations. The higher short-term memory scores among children who were co-exposed compared to non-exposed are perplexing and need replication, particularly in studies with larger sample sizes and samples exposed only to cannabis to examine this more closely.

Development and validation of the Cannabis Exposure in Pregnancy Tool (CEPT): a mixed methods study

BACKGROUND

Evidence of associations between prenatal cannabis use (PCU) and maternal and infant health outcomes remains conflicting amid broad legalization of cannabis across Canada and 40 American states. A critical limitation of existing evidence lies in the non-standardized and crude measurement of prenatal cannabis use (PCU), resulting in high risk of misclassification bias. We developed a standardized tool to comprehensively measure prenatal cannabis use in pregnant populations for research purposes.

METHODS

We conducted a mixed-methods, patient-oriented tool development and validation study, using a bias-minimizing process. Following an environmental scan and critical appraisal of existing prenatal substance use tools, we recruited pregnant participants via targeted social media advertising and obstetric clinics in Alberta, Canada. We conducted individual in-depth interviews and cognitive interviewing in separate sub-samples, to develop and refine our tool. We assessed convergent and discriminant validity internal consistency and 3-month test-retest reliability, and validated the tool externally against urine-THC bioassays.

RESULTS

Two hundred fifty four pregnant women participated. The 9-item Cannabis Exposure in Pregnancy Tool (CEPT) had excellent discriminant (Cohen's kappa = -0.27-0.15) and convergent (Cohen's kappa = 0.72-1.0) validity; as well as high internal consistency (Chronbach's alpha = 0.92), and very good test-retest reliability (weighted Kappa = 0.92, 95% C.I. [0.86-0.97]). The CEPT is valid against urine THC bioassay (sensitivity = 100%, specificity = 82%).

CONCLUSION

The CEPT is a novel, valid and reliable measure of frequency, timing, dose, and mode of PCU, in a contemporary sample of pregnant women. Using CEPT (compared to non-standardized tools) can improve measurement accuracy, and thus the quality of research examining PCU and maternal and child health outcomes.

Cannabis Use in Pregnancy and Neonatal Outcomes: A Systematic Review and Meta-Analysis

Objective: To determine whether prenatal cannabis use alone increases the likelihood of fetal and neonatal morbidity and mortality. Study Design: We searched bibliographic databases, such as PubMed, Embase, Scopus, Cochrane reviews, PsycInfo, MEDLINE, Clinicaltrials.gov, and Google Scholar from inception through February 14, 2022. Cohort or case-control studies with prespecified fetal or neonatal outcomes in pregnancies with prenatal cannabis use. Primary outcomes were preterm birth (PTB; <37 weeks of gestation), small-for-gestational-age (SGA), birthweight (grams), and perinatal mortality. Two independent reviewers screened studies. Studies were extracted by one reviewer and confirmed by a second using a predefined template. Risk of bias assessment of studies, using the Newcastle-Ottawa Quality Assessment Scale, and Grading of Recommendations Assessment, Development, and Evaluation for evaluating the certainty of evidence for select outcomes were performed by two independent reviewers with disagreements resolved by a third. Random effects meta-analyses were conducted, using adjusted and unadjusted effect estimates, to compare groups according to prenatal exposure to cannabis use status. Results: Fifty-three studies were included. Except for birthweight, unadjusted and adjusted meta-analyses had similar results. We found very-low- to low-certainty evidence that cannabis use during pregnancy was significantly associated with greater odds of PTB (adjusted odds ratio [aOR], 1.42; 95% confidence interval [CI], 1.19 to 1.69; I2, 93%; p=0.0001), SGA (aOR, 1.76; 95% CI, 1.52 to 2.05; I2, 86%; p<0.0001), and perinatal mortality (aOR, 1.5; 95% CI, 1.39 to 1.62; I2, 0%; p<0.0001), but not significantly different for birthweight (mean difference, -40.69 g; 95% CI, -124.22 to 42.83; I2, 85%; p=0.29). Because of substantial heterogeneity, we also conducted a narrative synthesis and found comparable results to meta-analyses. Conclusion: Prenatal cannabis use was associated with greater odds of PTB, SGA, and perinatal mortality even after accounting for prenatal tobacco use. However, our confidence in these findings is limited. Limitations of most existing studies was the failure to not include timing or quantity of cannabis use. This review can help guide health care providers with counseling, management, and addressing the limited existing safety data. Protocol Registration: PROSPERO CRD42020172343.

Birth, cognitive and behavioral effects of intrauterine cannabis exposure in infants and children: A systematic review and meta-analysis

BACKGROUND AND AIMS

Δ9-tetrahydrocannabinol (THC), the principal psychoactive component of cannabis, has been implicated in affecting fetal neurodevelopment by readily crossing the placenta. However, little is known regarding the long-term effects of intrauterine cannabis exposure. This systematic review and meta-analysis synthesized prospective and cross-sectional human studies to measure the effects of intrauterine cannabis exposure on birth, behavioral, psychological and cognitive outcomes in infancy until early childhood.

METHODS

Reporting according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, cross-sectional and prospective studies published from database inception until June 2023, investigating developmental outcomes of infants, toddlers and young children with intrauterine cannabis exposure were considered. All articles were obtained from PubMed or PsycINFO databases.

RESULTS

The literature search resulted in 932 studies, in which 57 articles met eligibility criteria. The meta-analysis revealed that intrauterine cannabis exposure increases the risk of preterm delivery [odds ratio (OR) = 1.68, 95% confidence interval (CI) = 1.05-2.71, P = 0.03], low birth weight (OR = 2.60, CI = 1.71-3.94, P < 0.001) and requirement for neonatal intensive care unit (NICU) admission (OR = 2.51, CI = 1.46-4.31; P < 0.001). Our qualitative synthesis suggests that intrauterine cannabis exposure may be associated with poorer attention and externalizing problems in infancy and early childhood. We found no evidence for impairments in other cognitive domains or internalizing behaviors.

CONCLUSIONS

Prenatal cannabis use appears to be associated with lower birth weight, preterm birth and neonatal intensive care unit admission in newborns, but there is little evidence that prenatal cannabis exposure adversely impacts behavioral or cognitive outcomes in early childhood, with the exception of attention and externalizing problems.

Prenatal alcohol and tetrahydrocannabinol exposure: Effects on spatial and working memory

Introduction

Alcohol and cannabis are widely used recreational drugs that can negatively impact fetal development, leading to cognitive impairments. However, these drugs may be used simultaneously and the effects of combined exposure during the prenatal period are not well understood. Thus, this study used an animal model to investigate the effects of prenatal exposure to ethanol (EtOH), Δ-9-tetrahydrocannabinol (THC), or the combination on spatial and working memory.

Methods

Pregnant Sprague-Dawley rats were exposed to vaporized ethanol (EtOH; 68 ml/h), THC (100 mg/ml), the combination, or vehicle control during gestational days 5-20. Adolescent male and female offspring were evaluated using the Morris water maze task to assess spatial and working memory.

Results

Prenatal THC exposure impaired spatial learning and memory in female offspring, whereas prenatal EtOH exposure impaired working memory. The combination of THC and EtOH did not exacerbate the effects of either EtOH or THC, although subjects exposed to the combination were less thigmotaxic, which might represent an increase in risk-taking behavior.

Discussion

Our results highlight the differential effects of prenatal exposure to THC and EtOH on cognitive and emotional development, with substance- and sex-specific patterns. These findings highlight the potential harm of THC and EtOH on fetal development and support public health policies aimed at reducing cannabis and alcohol use during pregnancy.

Impact of Prenatal Cannabis Use Disorder on Perinatal Outcomes

OBJECTIVES

With legislative changes to cannabis legalization and increasing prevalence of use, cannabis is the most commonly used federally illicit drug in pregnancy. Our study aims to assess the perinatal outcomes associated with prenatal cannabis use disorder.

METHODS

We conducted a retrospective cohort study using California linked hospital discharge-vital statistics data and included singleton, nonanomalous births occurring between 23 and 42 weeks of gestational age. χ 2 Test and multivariable logistic regression were used for statistical analyses.

RESULTS

A total of 2,380,446 patients were included, and 9144 (0.38%) were identified as using cannabis during pregnancy. There was a significantly increased risk for adverse birthing person outcomes, including gestational hypertension (adjusted odds ratio [AOR], 1.19; 95% confidence interval [CI], 1.06-1.34; P = 0.004), preeclampsia (AOR, 1.16; 95% CI, 1.0-1.28; P = 0.006), preterm delivery (AOR, 1.45; 95% CI, 1.35-1.55; P < 0.001), and severe maternal morbidity (AOR, 1.22; 95% CI, 1.02-1.47; P = 0.033). Prenatal cannabis use disorder was also associated with an increased risk of neonatal outcomes including respiratory distress syndrome (AOR, 1.16; 95% CI, 1.07-1.27; P < 0.001), small for gestational age (AOR, 1.47; 95% CI, 1.38-1.56; P < 0.001), neonatal intensive care unit admission (AOR, 1.24; 95% CI, 1.16-1.33; P < 0.001), and infant death (AOR, 1.86; 95% CI, 1.44-2.41; P < 0.001). There was no statistically significant difference in stillbirth (AOR, 0.96; 95% CI, 0.69-1.34; P = 0.80) and hypoglycemia (AOR, 1.22; 95% CI, 1.00-1.49; P = 0.045).

CONCLUSIONS

Our study suggests that prenatal cannabis use disorder is associated with increased maternal and neonatal morbidity and mortality. As cannabis use disorder in pregnancy is becoming more prevalent, our findings can help guide preconception and prenatal counseling.

Impacts of recreational cannabis legalization on use and harms: A narrative review of sex/gender differences

Legalization of cannabis use for non-medical (recreational) purposes is changing the global cannabis landscape. As attitudes toward cannabis use become more positive and prevalence of use increases in complex ways, concerns emerge about the potential for increased cannabis-attributable harms. Understanding the who, why, and when of this likely increase in cannabis-attributable harms is thus an important public health priority. Both sex and gender contribute to variability in the use, effects, and harms of cannabis and thus sex/gender considerations are important when evaluating the impacts of cannabis legalization. The goal of this narrative review is to broadly discuss sex/gender differences in attitudes toward and prevalence of cannabis use, whether there are sex/gender differences in the impacts of cannabis legalization, and why these sex/gender differences might exist. One of our strongest conclusions is that men have always been more likely to use cannabis than women, yet the sex/gender gap in prevalence of cannabis use has narrowed over time, and this might be partly due to cannabis legalization. The existing evidence suggests that there have also been sex/gender differences in the impacts of legalization on cannabis-attributable harms such as cannabis-involved motor vehicle collisions and hospitalizations, though these results are more variable. The body of literature reviewed has focused almost exclusively on samples of cisgender research participants, and thus future research should encourage inclusion of transgender and gender-diverse participants. More consideration of sex- and gender-based analysis in research evaluating long-term impacts of cannabis legalization is a clear research priority.

Associations between Prenatal and Postnatal Exposure to Cannabis with Cognition and Behavior at Age 5 Years: The Healthy Start Study

BACKGROUND

Prenatal exposure to cannabis may influence childhood cognition and behavior, but the epidemiologic evidence is mixed. Even less is known about the potential impact of secondhand exposure to cannabis during early childhood.

OBJECTIVE

This study sought to assess whether prenatal and/or postnatal exposure to cannabis was associated with childhood cognition and behavior.

STUDY DESIGN

This sub-study included a convenience sample of 81 mother-child pairs from a Colorado-based cohort. Seven common cannabinoids (including delta 9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD)) and their metabolites were measured in maternal urine collected mid-gestation and child urine collected at age 5 years. Prenatal and postnatal exposure to cannabis was dichotomized as exposed (detection of any cannabinoid) and not exposed. Generalized linear models examined the associations between prenatal or postnatal exposure to cannabis with the NIH Toolbox and Child Behavior Checklist T-scores at age 5 years.

RESULTS

In this study, 7% (n = 6) of the children had prenatal exposure to cannabis and 12% (n = 10) had postnatal exposure to cannabis, with two children experiencing this exposure at both time points. The most common cannabinoid detected in pregnancy was Δ9-THC, whereas the most common cannabinoid detected in childhood was CBD. Postnatal exposure to cannabis was associated with more aggressive behavior (β: 3.2; 95% CI: 0.5, 5.9), attention deficit/hyperactivity problems (β: 8.0; 95% CI: 2.2, 13.7), and oppositional/defiant behaviors (β: 3.2; 95% CI: 0.2, 6.3), as well as less cognitive flexibility (β: -15.6; 95% CI: -30.0, -1.2) and weaker receptive language (β: -9.7; 95% CI: -19.2, -0.3). By contrast, prenatal exposure to cannabis was associated with fewer internalizing behaviors (mean difference: -10.2; 95% CI: -20.3, -0.2) and fewer somatic complaints (mean difference: -5.2, 95% CI: -9.8, -0.6).

CONCLUSIONS

Our study suggests that postnatal exposure to cannabis is associated with more behavioral and cognitive problems among 5-year-old children, independent of prenatal and postnatal exposure to tobacco. The potential risks of cannabis use (including smoking and vaping) during pregnancy and around young children should be more widely communicated to parents.

The beneficial effect of sleep on behavioral health problems in youth is disrupted by prenatal cannabis exposure: A causal random forest analysis of Adolescent Brain Cognitive Development data

Studies suggest prenatal cannabis exposure is associated with mood/behavioral problems in children. However, it is unclear if targeting modifiable domains like sleep behaviors would improve outcomes in exposed youth. Using a causal inference framework, the effect of changing sleep-hours on changing internalizing/externalizing problems in children was examined using the Adolescent Brain Cognitive Development™ study baseline (ages 9-10; collected during 2016-2018) and year-1 follow-up data (N = 9825; 4663 female; 5196 white). Average treatment effects (ATE) indicated that more sleep predicted less internalizing (ATE = -.34, SE = .08, p < .001) and externalizing (ATE = -.29, SE = .07, p < .001) problems over time. However, prenatal cannabis exposure moderated the ATE on internalizing (conditional-ATE = .91, SE = .39, p = .019), whereby participants with exposure (n = 605) did not show any effect of changing sleep-hours on mood (B = .09, SE = .24).

Prenatal cannabis use and its impact on offspring neuro-behavioural outcomes: A systematic review

Introduction

Cannabis is a widely used substance in pregnancy, yet there is a paucity of literature addressing the neuro-behavioural consequences for prenatally exposed children. Our systematic review synthesizes currently available data for the impact of prenatal cannabis use on offspring intelligence and cognitive functioning.

Methods

MEDLINE, EMBASE, PsychINFO, CINAHL, and Clinicaltrials.gov were searched. Observational studies comparing prenatal cannabis use to controls were included. Offspring neuro-behavioural outcomes were grouped in prespecified domains of (1) intelligence and (2) cognitive functioning. Random-effect models were performed for meta-analyses when at least three studies reported the same outcome. All others were summarized qualitatively. GRADE (Grading of Recommendations, Assessment, Development and Evaluations) framework was used to assess evidence certainty.

Results

Of the 1982 reviewed studies (n = 523,107 patients), 28 were included. Significant heterogeneity and cohort redundancy limited meta-analysis. Very low-quality evidence from pooled analyses showed no significant associations between prenatal cannabis exposure and attention [standardized mean difference = -0.27 (95% CI = -0.60 to 0.07)], global intelligence quotient [-0.16 (-0.42 to 0.10)], reading [-0.05 (-0.29 to 0.20)], written comprehension [-0.09 (-0.40 to 0.22)], spelling [-0.04 (-0.26 to 0.17)], and mathematics [-0.01 (-0.15 to 0.13)]. No significant associations were found between prenatal cannabis exposure for all other outcomes. Individual studies reported significant differences between the heavy use groups and non-exposed, although this did not prove to be significant when outcomes were pooled.

Conclusions

The current review did not find a clear association between prenatal cannabis use and offspring neuro-behavioural outcomes. However, evidence was low quality and heterogenous. Further prospective investigation is needed to elucidate any potential association between prenatal cannabis use and long-term neuro-developmental outcomes.

Effects of Prenatal Cannabinoids Exposure upon Placenta and Development of Respiratory Neural Circuits

Cannabis use has risen dangerously during pregnancy in the face of incipient therapeutic use and a growing perception of safety. The main psychoactive compound of the Cannabis sativa plant is the phytocannabinoid delta-9-tetrahydrocannabinol (A-9 THC), and its status as a teratogen is controversial. THC and its endogenous analogues, anandamide (AEA) and 2-AG, exert their actions through specific receptors (eCBr) that activate intracellular signaling pathways. CB1r and CB2r, also called classic cannabinoid receptors, together with their endogenous ligands and the enzymes that synthesize and degrade them, constitute the endocannabinoid system. This system is distributed ubiquitously in various central and peripheral tissues. Although the endocannabinoid system's most studied role is controlling the release of neurotransmitters in the central nervous system, the study of long-term exposure to cannabinoids on fetal development is not well known and is vital for understanding environmental or pathological embryo-fetal or postnatal conditions. Prenatal exposure to cannabinoids in animal models has induced changes in placental and embryo-fetal organs. Particularly, cannabinoids could influence both neural and nonneural tissues and induce embryo-fetal pathological conditions in critical processes such as neural respiratory control. This review aims at the acute and chronic effects of prenatal exposure to cannabinoids on placental function and the embryo-fetal neurodevelopment of the respiratory pattern. The information provided here will serve as a theoretical framework to critically evaluate the teratogen effects of the consumption of cannabis during pregnancy.

Psychiatric medication use among pregnant and breastfeeding mothers who used cannabis for mental health concerns: A cross-sectional survey study

BACKGROUND

Use of cannabis during pregnancy and breastfeeding is increasing. Mental health concerns are reported as common reasons for maternal cannabis use, but little is known about the use of psychiatric medications in this population.

OBJECTIVES

This study aimed to describe psychiatric medication use among pregnant and breastfeeding mothers who used cannabis for mental health concerns.

DESIGN

Anonymous, online cross-sectional survey.

METHODS

Data were collected from May 2018 to August 2019 among pregnant and breastfeeding mothers who used cannabis. This study included mothers who reported cannabis use for mental health concerns (n = 1363). The survey assessed the timing of cannabis use (during pregnancy and/or lactation); use of cannabis to address depression, posttraumatic stress disorder, or anxiety; use of psychiatric medications; psychiatric distress (Patient Health Questionnaire-4); and demographic information. Differences between groups were examined using t-test and chi-square test in SPSS.

RESULTS

The mean age was 29.7 years; most were married (62%); 74% were White non-Hispanic, 9% Hispanic, and 17% Black, Indigenous or other People of Color. Mental health symptoms prompting cannabis use included anxiety (96%), depression (75%), and posttraumatic stress disorder (36%). Only 24% of respondents (n = 322) reported concomitant use of psychiatric medications, primarily selective serotonin reuptake inhibitors (72%, n = 232) and benzodiazepines (21%, n = 68). The composite Patient Health Questionnaire-4 showed most respondents had no (61%) or mild (27%) psychological distress; 14% screened positive for depression; and 17% screened positive for anxiety. Respondents who used psychiatric medications more often screened positive mental health concerns.

CONCLUSION

Most mothers who used cannabis for mental health concerns were not taking psychiatric medications. This may be due to a mismatch between perceived mental health and screening results, un- or under-treated mental illness, or preference for cannabis over psychiatric medications. Improved management of perinatal mental health and effective patient education about risks of cannabis versus medication use are needed.

A First-Tier Framework for Assessing Toxicological Risk from Vaporized Cannabis Concentrates

Vaporization is an increasingly prevalent means to consume cannabis, but there is little guidance for manufacturers or regulators to evaluate additive safety. This paper presents a first-tier framework for regulators and cannabis manufacturers without significant toxicological expertise to conduct risk assessments and prioritize additives in cannabis concentrates for acceptance, elimination, or further evaluation. Cannabinoids and contaminants (e.g., solvents, pesticides, etc.) are excluded from this framework because of the complexity involved in their assessment; theirs would not be a first-tier toxicological assessment. Further, several U.S. state regulators have provided guidance for major cannabinoids and contaminants. Toxicological risk assessment of cannabis concentrate additives, like other types of risk assessment, includes hazard assessment, dose-response, exposure assessment, and risk characterization steps. Scarce consumption data has made exposure assessment of cannabis concentrates difficult and variable. Previously unpublished consumption data collected from over 54,000 smart vaporization devices show that 50th and 95th percentile users consume 5 and 57 mg per day on average, respectively. Based on these and published data, we propose assuming 100 mg per day cannabis concentrate consumption for first-tier risk assessment purposes. Herein, we provide regulators, cannabis manufacturers, and consumers a preliminary methodology to evaluate the health risks of cannabis concentrate additives.

Impact of cannabinoids on pregnancy, reproductive health and offspring outcomes

Cannabis is the most commonly used federally illegal drug in the United States and world, especially among people of reproductive age. In addition, the potency of cannabis products has increased significantly in the past decade. This is concerning because the available evidence suggests an adverse effect from cannabis exposure on male and female reproductive health. Exposure to cannabinoids may have differential impacts on female reproductive health across a woman's lifespan, from preconception to pregnancy, throughout lactation, and during menopause. Even more, cannabis use has been associated an adverse effect on fetal outcomes, and longer-term offspring health and developmental trajectories. Despite the prevalence of cannabis use, there is limited available evidence regarding its safety, especially in regard to reproductive health, pregnancy and lactation. The biological effects of cannabis are mediated by the endocannabinoid system and studies have reported the presence of cannabinoid receptors in the male and female reproductive tract, on sperm and the placenta, suggesting the endocannabinoid system plays a role in regulating reproduction. Cannabis use can impact male and female fertility and has been associated with altered reproductive hormones, menstrual cyclicity and semen parameters. Use of cannabis in males has also been associated with erectile dysfunction, abnormal spermatogenesis, and testicular atrophy. In females, cannabis use has been associated with infertility and abnormal embryo implantation and development. The main psychoactive component of cannabis, delta-9-tetrahydrocannabinol (THC), can also cross the placenta and has been detected in breastmilk. Maternal cannabis use during pregnancy and lactation has been associated with adverse effects including small for gestational age infants, preterm birth, fetal neurodevelopmental consequences, and impaired offspring sociobehavioral and cognitive development. The prevalence of cannabis use to alleviate menopausal symptoms has also increased despite the limited information on its benefits and safety. As cannabis use is on the rise, it is critical to understand its impact on reproductive health and offspring developmental outcomes. This is an understudied, but timely subject, with much needed information to guide healthcare providers and those interested in conceiving, or that are pregnant and lactating, as well as those at the end of their reproductive time span.

Clinician responses to cannabis use during pregnancy and lactation: a systematic review and integrative mixed-methods research synthesis

BACKGROUND

Perinatal cannabis use is increasing, and clinician counselling is an important aspect of reducing the potential harm of cannabis use during pregnancy and lactation. To understand current counselling practices, we conducted a systematic review and integrative mixed-methods synthesis to determine "how do perinatal clinicians respond to pregnant and lactating patients who use cannabis?"

METHODS

We searched 6 databases up until 2021-05-31. Eligible studies described the attitudes, perceptions, or beliefs of perinatal clinician about cannabis use during pregnancy or lactation. Eligible clinicians were those whose practice particularly focusses on pregnant and postpartum patients. The search was not limited by study design, geography, or year. We used a convergent integrative analysis method to extract relevant findings for inductive analysis.

RESULTS

Thirteen studies were included; describing perspectives of 1,366 clinicians in 4 countries. We found no unified approach to screening and counselling. Clinicians often cited insufficient evidence around the effects of perinatal cannabis use and lacked confidence in counselling about use. At times, this meant clinicians did not address cannabis use with patients. Most counselled for cessation and there was little recognition of the varied reasons that patients might use cannabis, and an over-reliance on counselling focussed on the legal implications of use.

CONCLUSION

Current approaches to responding to cannabis use might result in inadequate counselling. Counselling may be improved through increased education and training, which would facilitate conversations to mitigate the potential harm of perinatal cannabis use while recognizing the benefits patients perceive.

Pregnant People's Perspectives On Cannabis Use During Pregnancy: A Systematic Review and Integrative Mixed-Methods Research Synthesis

Introduction

Rates of perinatal cannabis use are rising, despite clinical evidence about the potential for harm. Accordingly, pregnant and lactating people who perceive a benefit from cannabis use may have a difficult time making informed decisions about cannabis use.

Methods

We conducted a systematic review of mixed‐methods research to synthesize existing knowledge on the perspectives of pregnant people and their partners about cannabis use in pregnancy. Six health and social science databases were searched up until May 30, 2021. There were no methodological, time, or geographic limits applied. We employed a convergent integrative approach to the inductive analysis of findings from all studies.

Results

We identified 26 studies describing views of 17,781 pregnant and postpartum people about cannabis use in pregnancy. No studies describing the views of partners were identified, and only one study specifically addressed the perspectives of lactating people. Comparative analysis revealed that whether cannabis was studied alone or grouped with other substances resulted in significant diversity in descriptions of participant decision‐making priorities and perceptions of risks and benefits. Studies of cannabis alone demonstrated a complex decision‐making process whereby perceived benefits are balanced against the available information about risk, which is often unclear and uncertain. Clear and helpful information was difficult to identify, and health care providers were not described as a helpful and trusted resource for decision‐making.

Discussion

Decision‐making about cannabis use is difficult for pregnant and lactating people who perceive a benefit from this use, although this decisional difficulty is seldom reflected in studies that examine cannabis as one of multiple substances that pregnant or lactating people may use. Our review suggests several approaches clinicians may take to encourage open and supportive conversations to facilitate informed decisions about cannabis use during the perinatal period.

Tobacco and Cannabis Use During Pregnancy

OBJECTIVES

Nicotine (NIC) use during pregnancy can influence markers used in biochemical maternal serum screening. This study was designed to determine prevalence of disclosed tobacco smokers in our patient population and to compare disclosed tobacco smoking status with the presence of serum nicotine and a common tetrahydrocannabinol (THC) metabolite.

METHODS

A deidentified dataset of disclosed smoking status for quadruple (Quad) screens was obtained. Residual serum submitted for Quad screens was obtained from frozen storage and analyzed for NIC and THC metabolites.

RESULTS

Of specimens that had corresponding responses to the smoking history question on the patient history form, 7.2% (n = 1,783 of 24,611) specified that the patient was a tobacco smoker. Of the 271 specimens biochemically analyzed for NIC and THC metabolites, disclosed tobacco smokers had the highest prevalence of detectable NIC and THC metabolites. THC product use was most prevalent in patients categorized as probable tobacco smokers based on cotinine concentrations, as well as in younger patients.

CONCLUSIONS

Prevalence and concentration of NIC and THC metabolites vary based on disclosed tobacco smoker status. Biochemical testing may increase sensitivity for the identification of NIC and THC status over self-reporting.

Adverse childhood experiences and marijuana use during pregnancy: Findings from the North Dakota and South Dakota PRAMS, 2017-2019

BACKGROUND

Emerging research suggests that adverse childhood experiences (ACEs) may be a risk factor for prenatal marijuana use. This study is the first to use a representative sample from state surveillance systems to assess the connection between accumulating ACEs and marijuana use during pregnancy.

METHODS

Data are from the North Dakota and South Dakota Pregnancy Risk Assessment Monitoring System (PRAMS) from years 2017-2019 (N = 5399). The bivariate association between number of ACEs and marijuana use during pregnancy is assessed using a chi-square test. The multivariable association is assessed using linear probability modeling.

RESULTS

Only 0.9% of women with zero ACEs reported marijuana use during pregnancy, compared to 11.7% of women with four or more ACEs. Findings from linear probability models showed that mothers reporting two ACEs (b =0.023, 95% CI =0.003,.043), three ACEs (b =0.042, 95% CI =0.014,.069), and four or more ACEs (b =0.053, 95% CI =0.035,.071) are more likely to report marijuana use during pregnancy relative to those with zero ACEs, net of demographic and socioeconomic control variables.

CONCLUSIONS

Accumulating maternal ACEs -especially four or more- is associated with increased likelihood of using marijuana during pregnancy. These findings demonstrate the early life trauma is a key social determinant of health over the life course and highlights how ACEs can contribute to intergenerational harm via the worsening of health behaviors during pregnancy.

Lower-Risk Cannabis Use Guidelines (LRCUG) for reducing health harms from non-medical cannabis use: A comprehensive evidence and recommendations update

BACKGROUND

Cannabis use is common, especially among young people, and is associated with risks for various health harms. Some jurisdictions have recently moved to legalization/regulation pursuing public health goals. Evidence-based 'Lower Risk Cannabis Use Guidelines' (LRCUG) and recommendations were previously developed to reduce modifiable risk factors of cannabis-related adverse health outcomes; related evidence has evolved substantially since. We aimed to review new scientific evidence and to develop comprehensively up-to-date LRCUG, including their recommendations, on this evidence basis.

METHODS

Targeted searches for literature (since 2016) on main risk factors for cannabis-related adverse health outcomes modifiable by the user-individual were conducted. Topical areas were informed by previous LRCUG content and expanded upon current evidence. Searches preferentially focused on systematic reviews, supplemented by key individual studies. The review results were evidence-graded, topically organized and narratively summarized; recommendations were developed through an iterative scientific expert consensus development process.

RESULTS

A substantial body of modifiable risk factors for cannabis use-related health harms were identified with varying evidence quality. Twelve substantive recommendation clusters and three precautionary statements were developed. In general, current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the onset of cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high-frequency/-intensity of use, and refrain from smoking-routes for administration. While young people are particularly vulnerable to cannabis-related harms, other sub-groups (e.g., pregnant women, drivers, older adults, those with co-morbidities) are advised to exercise particular caution with use-related risks. Legal/regulated cannabis products should be used where possible.

CONCLUSIONS

Cannabis use can result in adverse health outcomes, mostly among sub-groups with higher-risk use. Reducing the risk factors identified can help to reduce health harms from use. The LRCUG offer one targeted intervention component within a comprehensive public health approach for cannabis use. They require effective audience-tailoring and dissemination, regular updating as new evidence become available, and should be evaluated for their impact.

Prenatal Cannabinoid Exposure: Emerging Evidence of Physiological and Neuropsychiatric Abnormalities

Clinical reports of cannabis use prevalence during pregnancy vary widely from 3% to upwards of 35% in North America; this disparity likely owing to underestimates from self-reporting in many cases. The rise in cannabis use is mirrored by increasing global legalization and the overall perceptions of safety, even during pregnancy. These trends are further compounded by a lack of evidence-based policy and guidelines for prenatal cannabis use, which has led to inconsistent messaging by healthcare providers and medically licensed cannabis dispensaries regarding prenatal cannabis use for treatment of symptoms, such as nausea. Additionally, the use of cannabis to self-medicate depression and anxiety during pregnancy is a growing medical concern. This review aims to summarize recent findings of clinical and preclinical data on neonatal outcomes, as well as long-term physiological and neurodevelopmental outcomes of prenatal cannabis exposure. Although many of the outcomes under investigation have produced mixed results, we consider these data in light of the unique challenges facing cannabis research. In particular, the limited longitudinal clinical studies available have not previously accounted for the exponential increase in (-)-Δ9- tetrahydrocannabinol (Δ9-THC; the psychoactive compound in cannabis) concentrations found in cannabis over the past two decades. Polydrug use and the long-term effects of individual cannabis constituents [Δ9-THC vs. cannabidiol (CBD)] are also understudied, along with sex-dependent outcomes. Despite these limitations, prenatal cannabis exposure has been linked to low birth weight, and emerging evidence suggests that prenatal exposure to Δ9-THC, which crosses the placenta and impacts placental development, may have wide-ranging physiological and neurodevelopmental consequences. The long-term effects of these changes require more rigorous investigation, though early reports suggest Δ9-THC increases the risk of cognitive impairment and neuropsychiatric disease, including psychosis, depression, anxiety, and sleep disorders. In light of the current trends in the perception and use of cannabis during pregnancy, we emphasize the social and medical imperative for more rigorous investigation of the long-term effects of prenatal cannabis exposure.