Cannabis Abuse or Dependence During Pregnancy: A Population-Based Cohort Study on 12 Million Births

Reduced fetal cerebral blood flow predicts perinatal mortality in a mouse model of prenatal alcohol and cannabinoid exposure

BACKGROUND

Children exposed prenatally to alcohol or cannabinoids individually can exhibit growth deficits and increased risk for adverse birth outcomes. However, these drugs are often co-consumed and their combined effects on early brain development are virtually unknown. The blood vessels of the fetal brain emerge and mature during the neurogenic period to support nutritional needs of the rapidly growing brain, and teratogenic exposure during this gestational window may therefore impair fetal cerebrovascular development.

STUDY DESIGN

To determine whether prenatal polysubstance exposure confers additional risk for impaired fetal-directed blood flow, we performed high resolution in vivo ultrasound imaging in C57Bl/6J pregnant mice. After pregnancy confirmation, dams were randomly assigned to one of four groups: drug-free control, alcohol-exposed, cannabinoid-exposed or alcohol-and-cannabinoid-exposed. Drug exposure occurred daily between Gestational Days 12-15, equivalent to the transition between the first and second trimesters in humans. Dams first received an intraperitoneal injection of either cannabinoid agonist CP-55,940 (750 µg/kg) or volume-equivalent vehicle. Then, dams were placed in vapor chambers for 30 min of inhalation of either ethanol or room air. Dams underwent ultrasound imaging on three days of pregnancy: Gestational Day 11 (pre-exposure), Gestational Day 13.5 (peri-exposure) and Gestational Day 16 (post-exposure).

RESULTS

All drug exposures decreased fetal cranial blood flow 24-hours after the final exposure episode, though combined alcohol and cannabinoid co-exposure reduced internal carotid artery blood flow relative to all other exposures. Umbilical artery metrics were not affected by drug exposure, indicating a specific vulnerability of fetal cranial circulation. Cannabinoid exposure significantly reduced cerebroplacental ratios, mirroring prior findings in cannabis-exposed human fetuses. Post-exposure cerebroplacental ratios significantly predicted subsequent perinatal mortality (p = 0.019, area under the curve, 0.772; sensitivity, 81%; specificity, 85.70%) and retroactively diagnosed prior drug exposure (p = 0.005; AUC, 0.861; sensitivity, 86.40%; specificity, 66.7%).

CONCLUSIONS

Fetal cerebrovasculature is significantly impaired by exposure to alcohol or cannabinoids, and co-exposure confers additional risk for adverse birth outcomes. Considering the rising potency and global availability of cannabis products, there is an imperative for research to explore translational models of prenatal drug exposure, including polysubstance models, to inform appropriate strategies for treatment and care in pregnancies affected by drug exposure.

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.

The association between prenatal cannabis use and congenital birth defects in offspring: A cumulative meta-analysis

OBJECTIVE

To examine the association between prenatal cannabis use and structural birth defects in exposed offspring.

METHODS

In line with the preregistered protocol (PROSPERO: CRD42022368623), we systematically searched PubMed/Medline, CINHAL, EMBASE, Web of Science, ProQuest, Psych-Info, and Google Scholar for published articles until 25 January 2024. The methodological quality of the included studies was appraised by the Newcastle-Ottawa Quality Assessment Scale (NOS). A meta-analysis was carried out to report the pooled effect estimates from the included studies. We further performed subgroup, leave-one-out sensitivity, and meta-regression analyses, which increased the robustness of our findings.

RESULTS

In this cumulative meta-analysis, thirty-six observational studies, consisting of 18 case-control and 18 cohort studies, with 230, 816 cases of birth defects and 18,049,013 controls (healthy babies) were included in the final analysis. We found that offspring exposed to maternal prenatal cannabis are at greater risks of a wide range of structural birth defects: cardiovascular/heart [OR = 2.35: 95 % CI 1.63 - 3.39], gastrointestinal [OR = 2.42: 95 % CI 1.61 - 3.64], central nervous system [OR = 2.87: 95 % CI 1.51 - 5.46], genitourinary [OR = 2.39: 95 % CI 1.11 - 5.17], and any (unclassified) birth defects [OR = 1.25: 95 % CI 1.12 - 1.41].

CONCLUSION

The findings from the current study suggest that maternal prenatal cannabis exposure is associated with a higher risk of different forms of structural birth defects in offspring. The findings underscore the significance of implementing preventive strategies, including enhanced preconception counselling, to address cannabis use during pregnancy and mitigate the risk of birth defects in offspring.

Substance use and treatment characteristics among pregnant and non-pregnant females, 2015-2019

INTRODUCTION

In the United States (US), pregnant females who use substances face increased morbidity and mortality risks compared to non-pregnant females. This study provides a national snapshot of substance use and treatment characteristics among US reproductive-aged females, including those who are pregnant.

METHODS

Our sample included females aged 15-44 years (n=97,830) from the 2015-2019 National Survey on Drug Use and Health (NSDUH) data. We calculated weighted percentages of past-month alcohol or drug use and past-year substance use disorder (SUD), stratified by pregnancy status. We also calculated weighted percentages of past-year treatment setting and payer. Pearson chi-square tests were conducted to determine if percentages were statistically significantly different.

RESULTS

Compared to non-pregnant females, pregnant females had lower prevalence of past-month illicit drug use excluding cannabis (1.6% vs. 4.3%, p<0.01), cannabis use (5.3% vs. 12.5%, p<0.01), binge drinking (4.5% vs. 29.3%, p<0.01) and past-year SUD (7.1 vs. 8.8%, p<0.01). Less than 13% of females with SUD received treatment regardless of pregnancy status, but treatment use was higher among pregnant females compared to non-pregnant females (12.8% vs. 10.5%). However, there were no statistically significant differences in past-year treatment use, setting, or treatment payer.

DISCUSSION

The prevalence of substance use and SUD was lower among pregnant females compared to non-pregnant females in 2015-2019. Low uptake of substance use treatment suggests that barriers exist to treatment-seeking among reproductive-aged women. Further exploration of stigma, payment, and access to treatment, and how they differ by pregnancy status, is needed.

The Effects of Cannabis Use during Pregnancy on Low Birth Weight and Preterm Birth: A Systematic Review and Meta-analysis

OBJECTIVE

 Our objective was to summarize the literature regarding the effects of cannabis use during pregnancy on low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA).

STUDY DESIGN

 This is a systematic review and meta-analysis. A literature search was conducted in PubMed, Scopus, EBSCO, and Web of Science in May 2021 and updated in November 2021. Only studies that assessed the isolated use of cannabis during pregnancy, controlling for cigarette smoking, and other illicit drug use were included. Data were synthesized using a narrative summary and pooled adjusted estimates, and 95% confidence intervals (CIs) were calculated for each outcome. Data were analyzed using Stata 13.0 with METAN software package, using random effects. Statistical heterogeneity was assessed using Cochran's Q and Higgins I2 tests.

RESULTS

 In total, 32 studies were included with data from approximately 5.5 million women with the LBW outcome and 23 million with the PTB and SGA outcomes. Pregnant women using cannabis are at increased risk for LBW (adjusted odds ratio [aOR] = 1.52; 95% CI = [1.18; 1.96]), PTB (aOR = 1.39; 95% CI = [1.28; 1.51]), and SGA (aOR = 1.47; 95% CI = [1.38; 1.58]). Studies that assessed the type of PTB and gestational age at birth indicate higher risks of spontaneous PTB and of early or very-early PTBs associated with cannabis use during pregnancy. The few studies that assessed the timing and frequency of consumption suggest a dose-response effect, with higher odds of negative outcomes among women who reported heavy use and with continued use during the second and third trimesters of gestation.

CONCLUSION

 There is an effect of cannabis irrespective of other illicit drugs and tobacco despite high heterogeneity and low quality of evidence. There is a need to discuss public policies regarding cannabis' regulation and how it influences its consumption. Future studies should focus on the effects of cannabis's type (medicinal or recreational), timing, and dosage during pregnancy on perinatal outcomes.

KEY POINTS

· Cannabis use during pregnancy is increasing.. · Cannabis has an independent effect on PTB, LBW, and SGA.. · Future studies should focus on the timing of exposure during pregnancy, mode of use, and dosage..

Exploring the associations between serious psychological distress and the quantity or frequency of tobacco, alcohol, and cannabis use among pregnant women in the United States

Serious Psychological Distress (SPD) and prenatal exposure to substances are associated with adverse outcomes for pregnant individuals and their developing offspring. This study aims to examine the relationship between SPD and quantity, or frequency of substance use among pregnant women in the United States (US). Descriptive and negative binomial regression analyses of the 2015-2019 National Survey on Drug Use and Health (NSDUH) were conducted among 3373 pregnant women (18 to 44 years old) to examine the association between SPD and (1) average number of cigarettes smoked in the past 30 days, (2) number of days of binge drinking in the past 30 days, and (3) number of days of cannabis use in the past 30 days. About 6% of the study population experienced SPD in the past 30 days. Compared to pregnant women who did not report SPD, pregnant women experiencing SPD showed greater rates in the number of cigarettes smoked during the past 30 days (IRR = 2.1, 95%CI = 1.1, 4.5), the number of days of binge drinking in the past 30 days (IRR = 5.1, 95%CI = 1.7, 15.4), and the number of days of cannabis use in the past 30 days (IRR = 2.9, 95%CI = 1.3, 6.5). Our results extend findings from prior research by documenting an association between SPD and the quantity and frequency of substance use among pregnant women in the US. Individual and structural interventions addressing SPD and/or substance might help reduce the impact of these comorbid conditions on expectant parents and their offspring.

Prenatal Exposure to Cannabis and Risk of Major Structural Birth Defects: A Systematic Review and Meta-analysis

OBJECTIVE

To review and perform a meta-analysis of observational studies that examined associations between prenatal cannabis exposure and major structural birth defects.

DATA SOURCES

Information sources included Google Scholar, BIOSIS, PubMed/MEDLINE, EMBASE CINAHL, and ClinicalTrials.gov.

METHODS OF STUDY SELECTION

Study titles and abstracts were reviewed with Abstrackr software. We included observational studies that examined the risk of major structural birth defects in people who used cannabis during pregnancy compared with those who had not used cannabis. We excluded case reports, ecologic studies, conference abstracts, manuscript preprints, studies designed to examine effects of cannabis used concurrently with other drugs, and studies that included synthetic cannabinoids. This process yielded 23 studies that analyzed data from birth years 1968-2021.

TABULATION, INTEGRATION, AND RESULTS

We clustered and meta-analyzed measures of association for birth defects by anatomic group. Eleven articles reported an association between cannabis use and the risk of a nonspecific outcome (eg, congenital anomaly). We estimated a pooled odds ratio of 1.33 (95% CI 1.14-1.56) and a pooled adjusted odds ratio (aOR) of 1.22 (95% CI 1.00-1.50). Anatomic groups examined were cardiac (nine studies), oral cleft (three studies), digestive (four studies), genitourinary (three studies), musculoskeletal (seven studies), and nervous system (five studies). Across most outcomes, we reported positive pooled unadjusted associations that were usually attenuated after the inclusion of only adjusted estimates. Two specific anomalies, with limited data, had pooled effect estimates that did not attenuate to the null after adjustment: Ebstein anomaly (two studies, aOR 2.19, 95% CI 1.25-3.82) and gastroschisis (five studies, aOR 2.50, 95% CI 1.09-5.740).

CONCLUSION

Studies examining associations between prenatal exposure to cannabis and major structural birth defects were heterogeneous. Most published effect estimates were unadjusted and scored low on our risk-of-bias assessment. Overall, we found inconsistent evidence to suggest that prenatal cannabis exposure is associated with birth defects. However, findings related to specific anomalies should be considered in further research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022319041.

Cannabis and Pregnancy: A Review

Importance

Prenatal cannabis use is rising and is a major public health issue. Cannabis use in pregnancy and during lactation has been associated with increased maternal and offspring morbidity and mortality.

Objective

This review aims to summarize the existing literature and current recommendations for cannabis use during pregnancy or lactation.

Evidence Acquisition

A PubMed, Cochrane Library, and Google Scholar literature search using the following terms was performed to gather relevant data: "cannabis," "cannabinoid," "delta-9-tetrahydrocannabinol," "THC," "cannabidiol," "fetal outcomes," "perinatal outcomes," "pregnancy," and "lactation."

Results

Available studies on cannabis use in pregnancy and during lactation were reviewed and support an association with increased risk of preterm birth, neonatal intensive care unit admission, low birth weight, and small-for-gestational-age infants.

Conclusion and Relevance

There is a critical need for research on the effects of cannabis use in pregnancy and during lactation. This is a necessary first step before furthering patient education, developing interventions, and targeting antenatal surveillance to ameliorate the adverse impacts on maternal and fetal health.

The effect of prenatal cannabis exposure on offspring preterm birth: a cumulative meta-analysis

BACKGROUND AND AIMS

Mixed results have been reported on the association between prenatal cannabis exposure and preterm birth. This study aimed to examine the magnitude and consistency of associations reported between prenatal cannabis exposure and preterm birth.

METHODS

This review was guided by the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. We performed a comprehensive search of the literature on the following electronic databases: PubMed, EMBASE, SCOPUS, Psych-INFO and Web of Science. The revised version of the Newcastle-Ottawa Scale (NOS) was used to appraise the methodological quality of the studies included in this review. Inverse variance weighted random-effects cumulative meta-analysis was undertaken to pool adjusted odds ratios (aOR) after sequential inclusion of each newly published study over time. The OR and 95% confidence interval (CI) limits required (stability threshold) for a new study to move the cumulative odds ratio to the null were also computed.

RESULTS

A total of 27 observational studies published between 1986 and 2022 were included in the final cumulative meta-analysis. The sample size of the studies ranged from 304 to 4.83 million births. Prenatal cannabis exposure was associated with an increased risk of preterm birth (pooled aOR = 1.35, 95% CI = 1.24-1.48). The stability threshold was 0.74 (95% CI limit = 0.81) by the end of 2022.

CONCLUSIONS

Offspring exposed to maternal prenatal cannabis use was associated with higher risk of preterm birth, which warrants public health messages to avoid such exposure, particularly during pregnancy.

Implementation of State Laws Giving Pregnant People Priority Access to Drug Treatment Programs in the Context of Coexisting Punitive Laws

BACKGROUND

In response to increased prenatal drug use since the 2000s, states have adopted treatment-oriented laws giving pregnant and postpartum people priority access to public drug treatment programs as well as multiple punitive policy responses. No prior studies have systematically characterized these state statutes or examined implementation of state priority access laws in the context of co-existing punitive laws.

METHODS

We conducted legal mapping to examine state priority access laws and their overlap with state laws deeming prenatal drug use to be child maltreatment, mandating reporting of prenatal drug use to child protective services, or criminalizing prenatal drug use. We also conducted interviews with 51 state leaders with expertise on their states' prenatal drug use laws to understand how priority access laws were implemented.

RESULTS

Thirty-three states and the District of Columbia have a priority access law, and more than 80% of these jurisdictions also have one of the punitive prenatal drug use laws described. Leaders reported major barriers to implementing state priority access laws, including the lack of drug treatment programs, stigma, and conflicts with punitive prenatal drug use laws.

CONCLUSIONS

Our results suggest that state laws granting pregnant and postpartum people priority access to drug treatment programs are likely insufficient to significantly increase access to evidence-based drug treatment. Punitive state prenatal drug use laws may counteract priority access laws by impeding treatment seeking. Findings highlight the need to allocate additional resources to drug treatment for pregnant and postpartum people.

Influence of prenatal cannabinoid exposure on early development and beyond

Public perception surrounding whether cannabis use is harmful during pregnancy often diverges greatly from the recommendations of doctors and healthcare providers. In contrast to the medical guidance of abstinence before, during, and after pregnancy, many women of reproductive age believe cannabis use during pregnancy is associated with little potential harm. Legalization and social cues support public perceptions that cannabis use during pregnancy is safe. Moreover, pregnant women may consider cannabis to be a safe alternative for treating pregnancy related ailments, including morning sickness. Compounding the problem is a lack of medical and federal guidance on safe, low, or high-risk levels of cannabis use. These issues mirror the continuing debate surrounding alcohol use and health, in particular, whether there are safe or lower risk levels of alcohol consumption during pregnancy. Clinical studies to date suffer from several limitations. First, most human studies are correlative in nature, meaning that causal associations cannot be made between in utero cannabis exposure and health and behavioral outcomes later in life. Due to obvious ethical constraints, it is not possible to randomly assign pregnant mothers to cannabis or other drug exposure conditions-a requirement needed to establish causality. In addition, clinical studies often lack quantitative information on maternal exposure (i.e., dose, frequency, and duration), include a small number of individuals, lack replication of outcome measures across cohorts, rely on self-report to establish maternal drug use, and suffer from unmeasured or residual confounding factors. Causal associations between maternal cannabis exposure and offspring outcomes are possible in preclinical cohorts but there is a large amount of heterogeneity across study designs and developmental differences between rodents and humans may limit translatability. In this review, we summarize research from human and preclinical models to provide insight into potential risks associated with prenatal cannabinoid exposure (PCE). Finally, we highlight gaps in knowledge likely to contribute to the growing divide between medical guidance and public attitudes regarding cannabis use during pregnancy.

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.

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.

Beliefs about marijuana use during pregnancy and breastfeeding held by residents of a Latino-majority, rural region of California

Marijuana use among pregnant and breastfeeding women is on the rise and carries risks for infant health and well-being. Decisions to use marijuana while pregnant and breastfeeding are motivated by beliefs that use poses minimal risk to infants and offers benefits to maternal users. Misperceptions and usage trend higher among disadvantaged populations. This study surveyed 401 community residents on beliefs about risks and benefits of marijuana use by pregnant and breastfeeding women. The study utilized techniques to enhance recruitment of Latino and disadvantaged residents of rural communities in California, a state where recreational marijuana use is legal. Analyses revealed substantial endorsement of beliefs about benefits and low risks of marijuana use while pregnant and breastfeeding, many of which run counter to current evidence. Misperceptions were particularly prevalent for cannabis users and male respondents. Trends in valid beliefs, while modest, were higher for Latinos and parents.

Maternal cannabis use during pregnancy and maternal and neonatal outcomes: A retrospective cohort study

OBJECTIVE

To examine the relationship between reported prenatal cannabis use and neonatal and maternal outcomes and whether the legalisation of cannabis in Canada affected the rates of reported use or the association with maternal and neonatal outcomes.

DESIGN

Population-based retrospective cohort study.

SETTING

Routinely collected data in a real-world setting.

POPULATION

All women in the Canadian province of Nova Scotia with singleton births between 1 January 2004 and 30 June 2021.

METHODS

The association between cannabis use and maternal and neonatal outcomes was examined using generalised linear models with inverse probability weighting.

MAIN OUTCOME MEASURES

Maternal and neonatal outcomes in the peripartum and postpartum period.

RESULTS

Rates of reported cannabis use in pregnancy increased from 1.3% to 7.5% over the study period with no appreciable change in slope after legalisation in 2018. Infants of mothers reporting cannabis use in pregnancy were more likely to have major anomalies and a 5-minute Apgar score ≤7, require neonatal intensive care unit admission, and had lower birthweight, head circumference and birth length than infants of mothers not reporting cannabis use. These associations did not differ before and after legalisation.

CONCLUSIONS

Reported cannabis use during pregnancy is associated with early postnatal complications and reduced fetal growth, even after taking into account a range of confounding factors. Rates of reported cannabis use during pregnancy increased over the past 5 years in Nova Scotia with no apparent additional effect of legalisation.

Congenital anomaly epidemiological correlates of Δ8THC across USA 2003-16: panel regression and causal inferential study

Δ8-Tetrahydrocannabinol (Δ8THC) is marketed in many US states as 'legal weed'. Concerns exist relating to class-wide genotoxic cannabinoid effects. We conducted an epidemiological investigation of Δ8THC-related genotoxicity expressed as 57 congenital anomaly (CA) rates (CARs) in the USA. CARs were taken from the Centers for Disease Control, Atlanta, Georgia. Drug exposure data were taken from the National Survey of Drug Use and Health, with a response rate of 74.1%. Ethnicity and income data were taken from the US Census Bureau. National cannabinoid exposure was taken from Drug Enforcement Agency publications and multiplied by state cannabis use data to derive state-based estimates of Δ8THC exposure. At bivariate continuous analysis, Δ8THC was associated with 23 CAs on raw CA rates, 33 CARs after correction for early termination for anomaly estimates and 41 on a categorical analysis comparing the highest and lowest exposure quintiles. At inverse probability weighted multivariable additive and interactive models lagged to 0, 2 and 4 years, Δ8THC was linked with 39, 8, 4 and 9 CAs. Chromosomal, cardiovascular, gastrointestinal, genitourinary, limb, central nervous system (CNS) and face systems were particularly affected. The minimum E-values ranged to infinity. Both the number of anomalies implicated and the effect sizes demonstrated were much greater for Δ8THC than for tobacco and alcohol combined. Δ8THC appears epidemiologically to be more strongly associated with many CAs than for tobacco and alcohol and is consistent with a cannabinoid class genotoxic/epigenotoxic effect. Quantitative causality criteria were fulfilled, and causal relationships either for Δ8THC or for cannabinoid/s, for which it is a surrogate marker, may be in operation.

Reasons for cannabis use during pregnancy and lactation: a qualitative study

BACKGROUND

Cannabis use among pregnant and lactating people is increasing, despite clinical evidence showing that cannabis use may be associated with low birth weight and childhood developmental deficits. Our objective was to understand why pregnant and lactating people use cannabis and how these motivations change across perinatal stages.

METHODS

Using qualitative, constructivist grounded theory methodology, we conducted telephone and virtual interviews with 52 individuals from across Canada. We selected participants using maximum variation and theoretical sampling. They were eligible if they had been pregnant or lactating within the past year and had decided to continue, cease or decrease their cannabis use during the perinatal period.

RESULTS

We identified 3 categories of reasons that people use cannabis during pregnancy and lactation: sensation-seeking for fun and enjoyment; symptom management of chronic conditions and conditions related to pregnancy; and coping with the unpleasant, but nonpathologized, experiences of life. Before pregnancy, participants endorsed reasons for using cannabis in these 3 categories in similar proportions, with many offering multiple reasons for use. During pregnancy, reasons for use shifted primarily to symptom management. During lactation, reasons returned to resemble those expressed before pregnancy.

INTERPRETATION

In this study, we showed that pregnant and lactating people use cannabis for many reasons, particularly for symptom management. Reasons for cannabis use changed across reproductive stages. The dynamic nature of the reasons for use across stages speaks to participant perception of benefits and risks, and perhaps a desire to cast cannabis use during pregnancy as therapeutic because of perceived stigma.

Cannabis Use in Pregnancy: A State of the Science Review

With a growing number of states legalizing recreational use, cannabis consumption during pregnancy is increasing. Population-based data and rigorous studies examining the association of cannabis use in pregnancy with perinatal outcomes are limited, but trends include preterm prelabor rupture of membranes, placenta previa, and an increased length of hospital stay. Neonates of pregnant persons who used cannabis during their pregnancy can be at increased risk of low birth weight, preterm birth, neonatal intensive care unit admission, neurocognitive deficits, and infectious and neurologic morbidity and mortality. This state of the science review examines the prevalence of cannabis use in pregnancy, its pharmacodynamics and how that is influenced by pregnancy, and associated adverse perinatal and neonatal outcomes. Implications for health care providers caring for pregnant persons using cannabis, especially in legalized states, are discussed.

Cannabis-related diagnosis in pregnancy and adverse maternal and infant outcomes

BACKGROUND

Cannabis use and cannabis use disorders are increasing in prevalence, including among pregnant women. The objective was to evaluate the association of a cannabis-related diagnosis (CRD) in pregnancy and adverse maternal and infant outcomes.

METHODS

We queried an administrative birth cohort of singleton deliveries in California between 2011-2017 linked to maternal and infant hospital discharge records. We classified pregnancies with CRD from International Classification of Disease codes. We identified nicotine and other substance-related diagnoses (SRD) in the same manner. Outcomes of interest included maternal (hypertensive disorders) and infant (prematurity, small for gestational age, NICU admission, major structural malformations) adverse outcomes.

RESULTS

From 3,067,069 pregnancies resulting in live births, 29,112 (1.0 %) had a CRD. CRD was associated with an increased risk of all outcomes studied; the strongest risks observed were for very preterm birth (aRR 1.4, 95 % CI 1.3, 1.6) and small for gestational age (aRR 1.4, 95 % CI 1.3, 1.4). When analyzed with or without co-exposure diagnoses, CRD alone conferred increased risk for all outcomes compared to no use. The strongest effects were seen for CRD with other SRD (preterm birth aRR 2.3, 95 % CI 2.2, 2.5; very preterm birth aRR 2.6, 95 % CI 2.3, 3.0; gastrointestinal malformations aRR 2.0, 95 % CI 1.6, 2.6). The findings were generally robust to unmeasured confounding and misclassification analyses.

CONCLUSIONS

CRD in pregnancy was associated with increased risk of adverse maternal and infant outcomes. Providing education and effective treatment for women with a CRD during prenatal care may improve maternal and infant health.

Assessing the prevalence and correlates of prenatal cannabis consumption in an urban Canadian population: a cross-sectional survey

BACKGROUND

Recreational cannabis use was legalized in Canada in October 2018. We aimed to determine the prevalence and correlates of cannabis consumption among pregnant individuals in a single Canadian city following national legalization.

METHODS

Over the period May to October 2019, we distributed an anonymous cross-sectional survey to pregnant patients attending family practice, midwifery, and low-risk and high-risk obstetrics clinics in Hamilton, Ontario. Eligibility was based on English literacy and current pregnancy. The survey included questions regarding lifetime and in-pregnancy cannabis use, intent for postpartum use and patterns of use. We also collected demographic information. We calculated descriptive statistics and performed logistic regression analyses to explore the relations between cannabis consumption and demographic characteristics.

RESULTS

Of 531 pregnant individuals approached, 478 agreed and were able to participate, for a 90% participation rate. Among these 478 respondents, 54 (11%) reported consuming cannabis at some point during the pregnancy and 20 (4%) reported currently consuming cannabis. Among the 460 respondents who intended to breastfeed, 23 (5%) planned to consume cannabis during the postpartum period. Of 20 current users, 13 (65%) reported consuming cannabis at least weekly and 19 (95%) reported nausea, sleep problems or anxiety as reasons for use. Respondents without postsecondary education had 10.0-fold (95% confidence interval [CI] 4.6-23.5) greater odds of prenatal cannabis consumption than university-educated respondents. In addition, respondents who reported that their partners used cannabis had 3.9-fold (95% CI 2.2-7.3) greater odds of prenatal cannabis consumption than those who reported that their partners did not use cannabis.

INTERPRETATION

Lower educational attainment and partners' cannabis consumption were associated with greater odds of inpregnancy cannabis use. These results may help to inform early intervention strategies to decrease cannabis consumption during this vulnerable period of fetal and neonatal development.

Perceived Risk of Weekly Cannabis Use, Past 30-Day Cannabis Use, and Frequency of Cannabis Use Among Pregnant Women in the United States

BACKGROUND

While accumulated evidence has shown that the prevalence of cannabis use among pregnant women in the US has increased in recent years, little is known about the specific subpopulations affected. The aim of this study was to estimate the prevalence and correlates of the perceived risk of weekly cannabis use, past 30-day cannabis use, and frequency of past 30-day cannabis use among US pregnant women.

METHODS

We analyzed data from 2,247 pregnant women 14 to 44 years of age surveyed in the 2015 to 2017 cross-sectional National Survey on Drug Use and Health. Analyses account for the sampling design. Primary outcomes included perceived risk of weekly cannabis use, past 30-day cannabis use, and frequency of cannabis use. We conducted multivariable logistic and negative binomial regression models to assess the associations between the primary outcomes and multiple correlates.

RESULTS

Among US pregnant women, 21.6% (95% CI=19.4, 23.8) did not perceive any risk associated with weekly cannabis use, 5.3% (95% CI=4.2, 6.5) used cannabis in the past 30 days, and among past-month users, the average number of days of use was 15.6 (95% CI=13.5, 17.7). Pregnant women living below the poverty line were both more likely to perceive no risk of weekly cannabis use (aOR=1.8; 95% CI=1.3, 2.5) and use cannabis more often in the past 30 days (aOR=2.9; 95% CI=1.5, 5.7) than pregnant women within an income bracket of more than two times the federal poverty threshold. Age, race, trimester of pregnancy, co-use of tobacco and/or alcohol were also associated with these outcomes.

CONCLUSION

Younger age, living in poverty, early trimester of pregnancy, and co-use of tobacco and/or alcohol increased the odds of cannabis use among pregnant women. As cannabis legalization spreads and cannabis use is increasingly perceived as safe, there is a growing need for research to determine the reasons why women in the identified at-risk subgroups are using cannabis during pregnancy.

Update on the developmental consequences of cannabis use during pregnancy and lactation

There is a strong increase in prevalence trends for cannabis use during pregnancy and lactation as more states legalize use of this drug. Information on the teratogenic risk of cannabis is limited but some important themes can be gleaned. Studies have not found a unique phenotypic signature of prenatal exposure but an increased risk of congenital anomalies, particularly gastroschisis, has been reported. Changes in fetal growth have been described in some epidemiological studies but long-term patterns of physical growth appear unaffected. Prenatal exposure to cannabis is not generally associated with reductions in global IQ but specific cognitive skills, especially attention and memory, can be negatively impacted. Long-term impacts on psychological health include increased rates of depressive symptoms and anxiety as well as delinquency. Relatively little is known about the risk of maternal cannabis use during lactation but data suggest that infant exposure is relatively low compared to maternal exposure. As delta-9-tetrahydrocannabinol (THC) levels increase to meet consumer demand and routes of exposure diversify, there is a strong need for prospective birth-cohort studies that collect biological samples to quantify exposure. Data from such studies will be critical to overcoming the weaknesses of past cannabis research and are essential to establishing reliable information on the risks of maternal use. Until that time, health care providers should be encouraged to talk about the risks and benefits associated with cannabis use during pregnancy and lactation with their patients, emphasizing that fetal and neonatal risks cannot be excluded at this time.

The association of cannabis use late in pregnancy with engagement and retention in perinatal substance use disorder care for opioid use disorder: A cohort comparison

BACKGROUND

Prenatal use of cannabis and opioids are increasing and very concerning. Engagement and retention in comprehensive, perinatal substance use disorder (PSUD) care are associated with better outcomes for mothers and babies. We compared the characteristics and engagement in care among women with opioid use disorder who used cannabis late in pregnancy versus those who didn't.

METHODS

The primary outcome, "overall engagement and retention in PSUD care" included: utilization of substance use treatment prenatally, negative screening/toxicology at delivery (excluding cannabis), and attendance at expected prenatal and postpartum visits. Cannabis use late in pregnancy was objectively assessed at delivery via maternal urine drug screen and/or neonatal meconium/cord toxicology. Between-group comparisons utilized chi square, t-test or Mann-Whitney. Associations were assessed using Spearman Rho and two multivariate, binary logistic regressions for cannabis use and the primary outcome.

RESULTS

18.0% (85/472) consumed cannabis late in pregnancy. Women of color, younger women, and those diagnosed with concurrent cannabis use disorder were more likely to consume cannabis. Engagement and retention in PSUD care was not associated with cannabis use, but rather, with prescribed pharmacotherapy for psychiatric disorders. The use of prescribed buprenorphine+naloxone was associated with cannabis avoidance late in pregnancy.

CONCLUSIONS

Cannabis use late in pregnancy, compared to none, did not impact engagement and retention in our PSUD program. Adjunctive psychotropic medication and/or buprenorphine+naloxone prescription were associated with cannabis avoidance suggesting the use and interactions of pharmacotherapies in an opioid dependent population is complex. A shared decision-making process during PSUD care is warranted.

Pregnant Canadians' Perceptions About the Transmission of Cannabis in Pregnancy and While Breastfeeding and the Impact of Information From Health Care Providers on Discontinuation of Use

OBJECTIVE

Rates of cannabis use during pregnancy and while breastfeeding are increasing in Canada. Some observational studies have found associations between cannabis use in pregnancy and low birthweight, preterm labour, and admission to the intensive care unit. This study aimed to evaluate women's perceptions about transmission of cannabis to the fetus, and whether receiving information from a health care provider influenced their decision to stop using cannabis during pregnancy.

METHODS

Pregnant women presenting to obstetrical, midwifery, and family practice clinics in the greater Hamilton, Ontario area were asked to complete an anonymous survey. Chi-square tests were used to investigate whether patient knowledge was influenced by health care providers or by self-directed learning and if this information influenced their decision to discontinue cannabis use.

RESULTS

Of the 478 women surveyed, the vast majority perceived that cannabis is transmitted to the fetus during pregnancy and to the infant while breastfeeding (94.3% and 91.2%, respectively). The majority of women (99%) indicated that the advent of cannabis legalization did not influence their choice to use cannabis in pregnancy. Women who continued to use cannabis during pregnancy were more likely to report receiving information on cannabis from a health care provider (52%) than those who chose to discontinue use in pregnancy (35%) (P = 0.035).

CONCLUSIONS

In our study, the proportion of pregnant women who understood that cannabis could be transmitted to the fetus in utero and to the infant via breastmilk was high. Despite this, 4.2% of women reported that they continued to use cannabis in pregnancy. More work is needed to understand why some women continue to use cannabis in pregnancy despite being informed of its risks.

Monitoring Perinatal Exposure to Cannabis and Synthetic Cannabinoids

PURPOSE

Drug use during pregnancy is a critical global challenge, capable of severe impacts on neonatal development. However, the consumption of cannabis and synthetic cannabinoids is on the rise in pregnant women. Obstetric complications with increased risks of miscarriage, fetal growth restriction, and brain development impairment have been associated with perinatal cannabis exposure, but data on synthetic cannabinoid use during pregnancy are limited.

METHODS

We reviewed studies that investigated the risks associated with cannabis and synthetic cannabinoid use and those that reported the concentrations of cannabinoids and synthetic cannabinoids in maternal (breast milk) and neonatal (placenta, umbilical cord, meconium, and hair) matrices during human pregnancy. A MEDLINE and EMBASE literature search to identify all relevant articles published in English from January 1998 to April 2019 was performed.

RESULTS

Cannabis use during pregnancy is associated with increased risks of adverse obstetrical outcomes, although neurobehavioral effects are still unclear. Analyses of cannabinoids in meconium are well documented, but further research on other unconventional matrices is needed. Adverse effects due to perinatal synthetic cannabinoid exposure are still unknown, and analytical data are scarce.

CONCLUSIONS

Awareness of the hazards of drug use during pregnancy should be improved to encourage health care providers to urge pregnant women to abstain from cannabis and, if cannabis-dependent, seek treatment. Moreover, substances used throughout pregnancy should be monitored as a deterrent to cannabis use, and potential cannabis-dependent women should be identified, so as to limit cannabis-fetal exposure during gestation, and provided appropriate treatment.

Prevalence of cannabis use has significantly increased in patients with cyclic vomiting syndrome

INTRODUCTION

Cyclic vomiting syndrome (CVS) is a functional gastrointestinal disorder which leads to multiple hospitalizations and causes significant impairment of quality of life. Cannabis use is common in patients with CVS, and there are limited data on the national trends in the prevalence of its use in the United States.

METHODS

We used the National Inpatient Sample (NIS) database from 2005 to 2014 and identified hospitalizations with a primary diagnosis of CVS by utilizing the International Classification of Diseases, 9th revision Clinical Modification (ICD-9 CM) coding system. The primary objective of the study was to analyze the prevalence and trends in cannabis use in CVS patients. We also assessed healthcare resource utilization associated with cannabis use.

RESULTS

A total of 129 090 hospitalizations with a primary diagnosis of CVS were identified and included in the study. In the United States, the overall rate of cannabis use among these patients was 104 per 1000 hospitalizations (N = 13 460). Over the last decade, the prevalence of cannabis use increased by 10-fold, from 2.2% in 2005 to 21.2% in 2014.

CONCLUSION

Our analysis of the national database suggests that nearly 1 in 5 CVS hospitalizations have concurrent cannabis use. This prevalence is significantly rising over the last decade, perhaps due to changing legislation and increased utilization of cannabis. Age younger than 35, male gender, African American and Native American race, personal history of alcohol abuse and tobacco use were some of the strongest predictors of cannabis use.

Recreational Cannabis Legalization in the US and Maternal Use during the Preconception, Prenatal, and Postpartum Periods

In the United States (US), recreational cannabis use is on the rise. Since 2011, 11 states and the District of Columbia have legalized cannabis for adult recreational use. As additional states consider legalizing, there is an urgent need to assess associations between recreational cannabis legalization and maternal use in the preconception, prenatal, and postpartum periods—all critical windows for maternal and child health. Using cross-sectional data from the 2016 Pregnancy Risk Assessment Monitoring System, we assessed associations between state cannabis legalization and self-reported maternal cannabis use. Using logistic regression, we estimated the adjusted prevalence ratio (PR) of cannabis use during the preconception, prenatal, and postpartum period for women delivering a live-born infant in three states that had legalized recreational cannabis (Alaska, Colorado, and Washington) and three states that had not legalized (Maine, Michigan, and New Hampshire) by 2016. Our final sample size was 7258 women. We utilized 95% confidence intervals (CI) and a significance level of alpha = 0.05. After adjustment for potential confounders, women who resided in states with legalized recreational cannabis were significantly more likely to use cannabis during the preconception (PR 1.52; 95%CI ranging from 1.28–1.80; p < 0.001), prenatal (PR 2.21; 95% CI ranging from 1.67–2.94; p < 0.001), and postpartum (PR 1.73; 95%CI ranging from 1.30–2.30; p < 0.001) periods, compared to women who resided in states without legalized recreational cannabis. Although evidence about the effect of marijuana use during these periods is nascent, these findings show potential for increased incidence of child exposure to cannabis. Longitudinal research is needed to assess immediate and sustained impacts of maternal use before and after state legalization of recreational cannabis.

Position Statement on the Use of Medical Cannabis for the Treatment of Epilepsy in Canada

In Canada, recreational use of cannabis was legalized in October 2018. This policy change along with recent publications evaluating the efficacy of cannabis for the medical treatment of epilepsy and media awareness about its use have increased the public interest about this agent. The Canadian League Against Epilepsy Medical Therapeutics Committee, along with a multidisciplinary group of experts and Canadian Epilepsy Alliance representatives, has developed a position statement about the use of medical cannabis for epilepsy. This article addresses the current Canadian legal framework, recent publications about its efficacy and safety profile, and our understanding of the clinical issues that should be considered when contemplating cannabis use for medical purposes.

Association Between Self-reported Prenatal Cannabis Use and Maternal, Perinatal, and Neonatal Outcomes

IMPORTANCE

Recent evidence suggests that cannabis use during pregnancy is increasing, although population-based data about perinatal outcomes following in utero exposure remain limited.

OBJECTIVE

To assess whether there are associations between self-reported prenatal cannabis use and adverse maternal and perinatal outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Population-based retrospective cohort study covering live births and stillbirths among women aged 15 years and older in Ontario, Canada, between April 2012 and December 2017.

EXPOSURES

Self-reported cannabis exposure in pregnancy was ascertained through routine perinatal care.

MAIN OUTCOMES AND MEASURES

The primary outcome was preterm birth before 37 weeks' gestation. Indicators were defined for birth occurring at 34 to 36 6/7 weeks' gestation (late preterm), 32 to 33 6/7 weeks' gestation, 28 to 31 6/7 weeks' gestation, and less than 28 weeks' gestation (very preterm birth). Ten secondary outcomes were examined including small for gestational age, placental abruption, transfer to neonatal intensive care, and 5-minute Apgar score. Coarsened exact matching techniques and Poisson regression models were used to estimate the risk difference (RD) and relative risk (RR) of outcomes associated with cannabis exposure and control for confounding.

RESULTS

In a cohort of 661 617 women, the mean gestational age was 39.3 weeks and 51% of infants were male. Mothers had a mean age of 30.4 years and 9427 (1.4%) reported cannabis use during pregnancy. Imbalance in measured maternal obstetrical and sociodemographic characteristics between reported cannabis users and nonusers was attenuated using matching, yielding a sample of 5639 reported users and 92 873 nonusers. The crude rate of preterm birth less than 37 weeks' gestation was 6.1% among women who did not report cannabis use and 12.0% among those reporting use in the unmatched cohort (RD, 5.88% [95% CI, 5.22%-6.54%]). In the matched cohort, reported cannabis exposure was significantly associated with an RD of 2.98% (95% CI, 2.63%-3.34%) and an RR of 1.41 (95% CI, 1.36-1.47) for preterm birth. Compared with no reported use, cannabis exposure was significantly associated with greater frequency of small for gestational age (third percentile, 6.1% vs 4.0%; RR, 1.53 [95% CI, 1.45-1.61]), placental abruption (1.6% vs 0.9%; RR, 1.72 [95% CI, 1.54-1.92]), transfer to neonatal intensive care (19.3% vs 13.8%; RR, 1.40 [95% CI, 1.36-1.44]), and 5-minute Apgar score less than 4 (1.1% vs 0.9%; RR, 1.28 [95% CI, 1.13-1.45]).

CONCLUSIONS AND RELEVANCE

Among pregnant women in Ontario, Canada, reported cannabis use was significantly associated with an increased risk of preterm birth. Findings may be limited by residual confounding.