A prospective study on intrauterine cannabis exposure and fetal blood flow

Exposure to maternal cannabis use disorder and risk of autism spectrum disorder in offspring: A data linkage cohort study

This study aimed to investigate the association between pre-pregnancy, prenatal and perinatal exposures to cannabis use disorder (CUD) and the risk of autism spectrum disoder (ASD) in offspring. Data were drawn from the New South Wales (NSW) Perinatal Data Collection (PDC), population-based, linked administrative health data encompassing all-live birth cohort from January 2003 to December 2005. This study involved 222 534 mother-offspring pairs. . The exposure variable (CUD) and the outcome of interest (ASD) were identified using the 10th international disease classification criteria, Australian Modified (ICD-10-AM). We found a three-fold increased risk of ASD in the offspring of mothers with maternal CUD compared to non-exposed offspring. In our sensitivity analyses, male offspring have a higher risk of ASD associated with maternal CUD than their female counterparts. In conclusion, exposure to maternal CUD is linked to a higher risk of ASD in offspring, with a stronger risk in male offspring. Further research is needed to understand these gender-specific effects and the relationship between maternal CUD and ASD risk in children.

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.

Combined exposure to alcohol and cannabis during development: Mechanisms and outcomes

Exposure to substances of abuse during pregnancy can have long-lasting effects on offspring. Alcohol is one of the most widely used substances of abuse that leads to the most severe consequences. Recent studies in the United States, Canada, and the United Kingdom showed that between 1% and 7% of all children exhibit signs and symptoms of fetal alcohol spectrum disorder (FASD). Despite preventive campaigns, the rate of children with FASD has not decreased during recent decades. Alcohol consumption often accompanies exposure to such drugs as tobacco, cocaine, opioids, and cannabis. These interactions can be synergistic and exacerbate the deleterious consequences of developmental alcohol exposure. The present review focuses on interactions between alcohol and cannabis exposure and the potential consequences of these interactions.

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.

Up in Smoke: The Impacts of Marijuana During Pregnancy

Numerous drugs ingested during pregnancy can impact the developing fetus. Although some effects are apparent at birth as overt teratogenicity or profound neonatal withdrawal, others become apparent only after a careful long-term follow-up into childhood. Shifting legal and cultural attitudes toward marijuana have led to increased use during pregnancy. This shift should prompt health care providers to carefully consider the drug's mechanism of action, its interaction with the placenta, and the potential consequences of fetal exposure. The primary psychoactive compound in marijuana is Δ9-tetrahydrocannabinol (THC), which agonizes endogenous cannabinoid receptors. Cannabinoid receptors are present in the fetal brain early in gestation and appear to have an important role in the developing central nervous system. THC crosses the placenta in sufficient quantities to raise concerns about exogenous exposure during fetal development. Robust follow-up studies suggest that marijuana use during pregnancy contributes to suboptimal fetal growth. At school age, heavy prenatal marijuana exposure predicts challenges in executive function (specifically, memory and reasoning) and externalizing behavior (e.g., hyperactivity and inattention). Memory and behavioral problems persist into early adulthood. These challenges coincide with a higher risk of heavy marijuana use in offspring. In concert with a suboptimal environment, young adults may experience a higher risk of global cognitive impairment and/or delinquency. Importantly, these adverse outcomes appear to be mitigated by postnatal factors including home environment. Ongoing studies in the modern era will be vital to enhance our understanding of the mechanisms by which THC impacts the fetus and confirm or refute knowledge regarding long-term impact. This knowledge will inform both health care providers and parents in collaborative decision-making to optimize the outcome of children.

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.

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.

Impact of maternal substance use on offspring's cardiovascular health

Substance use (SU) during pregnancy is on the rise, posing significant risks to the developing fetus. The adverse impact of maternal alcohol and nicotine use during the perinatal period on offspring health has been well established, including their associations with adverse cardiovascular health in offspring. However, limited studies examine the impact of other well-known SU utilized during pregnancy on offspring's cardiovascular health. This review summarizes the proposed mechanism of action of four commonly utilized substances: cocaine, marijuana, methamphetamine, and opioids, and their cardiovascular impact. Furthermore, we will review the current understanding of the adverse impact of substance use during pregnancy on offspring's cardiovascular system based on existing studies. This review will also highlight possible molecular mechanisms underlying the in-utero adverse programming of offspring's cardiovascular system secondary to SU in pregnancy and address the gaps in current understanding of how SU adversely impacts the developing cardiovascular system of offspring in utero.

Intrauterine cannabis exposure and fetal and maternal blood flow: a case-control study

INTRODUCTION

Cannabis consumption during pregnancy increases the risk of pregnancy and neonatal complications. Since the underlying mechanism is unknown, the purpose of this study is to evaluate the changes in maternal and fetal blood flow in pregnancies exposed to cannabis, Δ9-tetrahydrocannabinol (THC).

MATERIAL AND METHODS

A case-control study between 2013 and 2020, included women with continued cannabis exposure during the pregnancies, defined by qualitative detection of THC in urine (Cannabis Group), and low-risk pregnancy women divided into tobacco smokers (Tobacco Group), and non-tobacco smokers (Control Group). We evaluated the association between cannabis consumption and maternal and fetal blood flow parameters measured by Doppler ultrasound: uterine artery at 11-14, 20-22 and 33-35 weeks, umbilical artery and middle cerebral artery at 33-35 weeks. Cerebral-placental ratio was calculated.

RESULTS

Overall, 275 participants were included, 60 in the Cannabis Group, 17 in the Tobacco Group and 198 in the Control Group. At 33-35 weeks, differences were found in the umbilical artery pulsatility index (PI) (1.05 ± 0.23, 1.06 ± 0.19, 0.93 ± 0.15, P < 0.01), middle cerebral artery PI (1.75 ± 0.35, 1.90 ± 0.45, 1.88 ± 0.34, P < 0.05), cerebral-placental ratio (1.69 ± 0.40, 1.85 ± 0.53, 2.07 ± 0.47, P < 0.05) and mean uterine artery PI (0.89 ± 0.26, 0.73 ± 0.19, 0.74 ± 0.20, P < 0.01), respectively. On logistic regression analysis, adjusted for maternal age, maternal body mass index, maternal weight and white ethnicity, both cannabis and tobacco were predictors for increased umbilical artery PI, but only cannabis was a predictor for a decreased cerebral-placental ratio and an increased uterine artery PI at 33-35 weeks.

CONCLUSIONS

Data from a large cohort of continuous cannabis exposure pregnancies show that cannabis is associated with maternal and fetal blood flow changes. However, it is not possible to disentangle the association of the tobacco and cannabis.

Maternal preconception and pregnancy tobacco and cannabis use in relation to placental developmental markers: A population-based study

Maternal tobacco and cannabis use during pregnancy are associated with adverse perinatal outcomes. We hypothesized that maternal tobacco and cannabis use are associated with placental adaptations, which subsequently lead to adverse perinatal outcomes. In a population-based prospective cohort study of 8008 pregnant women, we assessed maternal tobacco and cannabis use by questionnaires. Placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were measured in the first and second trimester and at delivery from blood samples. Placental weight and pregnancy complications were obtained from medical records. We observed that tobacco use before and during first-trimester only was not associated with any angiogenic factors. As compared to no tobacco use, continued use during pregnancy was associated with higher PlGF, lower sFlt-1 concentrations, and lower sFlt-1/PlGF ratio in second trimester (all p-values <0.05). Also, compared to no cannabis use, use before and during pregnancy was associated with higher PlGF concentrations and lower sFlt-1/PlGF ratio in first and second trimester (all p-values <0.05). First trimester only cannabis use was associated with higher sFlt-1 concentrations and higher sFlt-1/PlGF ratio at delivery (all p-values <0.05). Compared to non-use, tobacco use before pregnancy was associated with a higher placental weight, whereas continued tobacco use during pregnancy was associated with a lower placental weight. Continued tobacco or cannabis use was related to higher placental weight to birth weight ratio and higher risk of pregnancy complications (all p-values <0.05). These results suggest that maternal tobacco and cannabis use lead to placental vascular maladaptation predisposing to adverse pregnancy outcomes.

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.

Association between gestational cannabis exposure and maternal, perinatal, placental, and childhood outcomes

Globally, the availability and formulations for the administration of cannabis are changing with decriminalization or legalization of recreational use in some jurisdictions, and the prescription of cannabis also occurring. These changes are likely to affect the prevalence of use, including by women of childbearing age. The effects of in utero and infant alcohol and tobacco exposure are well-documented, but the outcomes of cannabis exposure are less certain. The content of delta-9-tetrahydrocannabinol (THC), the psychoactive component of cannabis has progressively increased over several decades. This review explores the limited knowledge surrounding the epidemiology of gestational and postnatal cannabis exposure and implications for the mother-placenta-fetus/neonate triad. We examine cannabis' effects from antenatal and lactation exposure on (a) pregnancy and perinatal outcomes, (b) placental health, and (c) longer term cardiometabolic and neurodevelopmental risks and outcomes. Though definitive outcomes are lacking, gestational cannabis has been associated with increased risk of other substance use during pregnancy; impaired placental blood flow; increased risk of small for gestational age births; and associated complications. Childhood and adolescent outcomes are sparsely assessed, with suggested outcomes including increased risk of depression and attention-deficit hyperactivity disorder. Cardiometabolic implications of gestational cannabis use may include maternal fatty liver, obesity, insulin resistance, and increased risk of gestational diabetes mellitus (GDM), with potential consequences for the fetus. Clinical implications for pediatric practice were explored in a bid to understand any potential risk or impact on child health and development.

Interaction of maternal choline levels and prenatal Marijuana's effects on the offspring

BACKGROUND

This study investigated whether higher maternal choline levels mitigate effects of marijuana on fetal brain development. Choline transported into the amniotic fluid from the mother activates α7-nicotinic acetylcholine receptors on fetal cerebro-cortical inhibitory neurons, whose development is impeded by cannabis blockade of their cannabinoid-1(CB1) receptors.

METHODS

Marijuana use was assessed during pregnancy from women who later brought their newborns for study. Mothers were informed about choline and other nutrients, but not specifically for marijuana use. Maternal serum choline was measured at 16 weeks gestation.

RESULTS

Marijuana use for the first 10 weeks gestation or more by 15% of mothers decreased newborns' inhibition of evoked potentials to repeated sounds (d' = 0.55, p < 0.05). This effect was ameliorated if women had higher gestational choline (rs = -0.50, p = 0.011). At 3 months of age, children whose mothers continued marijuana use through their 10th gestational week or more had poorer self-regulation (d' = -0.79, p < 0.05). This effect was also ameliorated if mothers had higher gestational choline (rs = 0.54, p = 0.013). Maternal choline levels correlated with the children's improved duration of attention, cuddliness, and bonding with parents.

CONCLUSIONS

Prenatal marijuana use adversely affects fetal brain development and subsequent behavioral self-regulation, a precursor to later, more serious problems in childhood. Stopping marijuana use before 10 weeks gestational age prevented these effects. Many mothers refuse to cease use because of familiarity with marijuana and belief in its safety. Higher maternal choline mitigates some of marijuana's adverse effects on the fetus.

Phytochemical analysis of ionic liquid-Graviola (Annona muricata) fruit extract and its acute toxicity on zebrafish early-life stages

Annona muricata, commonly known as soursop and Graviola, is a member of the Annonaceae family. Some of its phytochemicals were reported to have a neurotoxicity effect causing neurodegenerative diseases. However, different parts of this tree have been used for ages in traditional medicine due to their biological activities, such as anti-inflammatory, antimicrobial, antioxidant and anticancer effects. This study aimed to qualitatively screen the crude ionic liquid-Graviola fruit extract (IL-GFE) phytochemical composition, assess its acute toxicity and determine the lethal concentrations using zebrafish (Danio rerio) embryos. IL-GFE contains acetogenins, alkaloids, phenols, terpenoids, tannins and flavonoids. Acute toxicity effects of IL-GFE on zebrafish embryos were observed from 24 to 120 hours of post fertilisation (hpf). The survival rate, LC50, sublethal endpoints and effect of IL-GFE on the heart rate of zebrafish larvae were assessed. Results showed that the lethal concentration (LC50) of the crude IL-GFE was 173.45 μg/mL. Interestingly, no significant changes on the morphology of the treated zebrafish were observed at a concentration of 125 μg/mL. However, the heart rate of zebrafish larvae at 96 hpf was significantly decreased by 33.76% after treated with crude IL-GFE at 125 µg/mL (119.00 ± 4.72 beats/min) as compared to the untreated group (179.67 ± 4.66 beats/min). This preliminary finding showed that crude ionic liquid-Graviola fruit extract and its phytoconstituents might have the potential to be developed as a food supplement or herbal product. However, further tests need to be conducted to evaluate its medicinal properties and adverse effects on organisms of higher orders.

Pregnancy outcome among women with drug dependence: A population-based cohort study of 14 million births

OBJECTIVE

Drug dependence is on the rise worldwide. The purpose of this study is to examine the association between drug dependency in pregnancy (DDP) and maternal and newborn outcomes.

METHODS

We carried out a population-based retrospective cohort study evaluating DDP using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from 1999 to 2014. DDP was identified using ICD-9 coding. The associations between DDP and maternal and newborn outcomes were estimated using multivariate logistic regression analyses to estimate adjusted odds ratios and 95 % confidence intervals.

RESULTS

Among 14,513,587 deliveries, 50,570 were to mothers with DDP for an overall prevalence of 35 cases/10,000 deliveries. The rate of pregnancies to drug-dependent women increased during the 15-year study period, from approximately 25/10,000 in 1999 to 69/10,000 in 2014. Women with DDP were younger in age, users of tobacco, and in lower income quartiles with more pre-existing health conditions, such as diabetes and hypertension. DDP was associated with greater risk of venous thromboembolism (OR 1.60; 95 % CI, 1.45-1.76), sepsis (OR 2.94; 95 % CI, 2.48-3.49), and maternal death (OR 2.77; 95 % CI, 1.88-4.08). Neonates born to mothers with drug dependence were at higher risk of prematurity (OR 1.37; 95 % CI, 1.33-1.41), intrauterine growth restriction (OR 1.60; 95 % CI, 1.54-1.67), and intrauterine fetal death (OR 1.27; 95 % CI, 1.16-1.40).

CONCLUSION

DDP is increasing in frequency and it is associated with maternal and newborn deaths and adverse events. Further research and public health initiatives should be undertaken to address prevention, screening, and treatment.

Marijuana Use in Pregnancy: A Review

Importance

Marijuana is the most commonly used dependent substance in pregnancy. The main active chemical of marijuana (delta-9-tetrahydrocannabinol [THC]) readily crosses the placenta, and cannabinoid receptors have been identified in fetal brain and placenta. As a result, prenatal marijuana use could potentially have detrimental impact on fetal development.

Objective

This review aims to summarize the existing literature and current recommendations for marijuana use while pregnant or lactating.

Evidence Acquisition

A PubMed literature search using the following terms was performed to gather relevant data: "cannabis," "cannabinoids," "marijuana," "fetal outcomes," "perinatal outcomes," "pregnancy," "lactation."

Results

Available studies on marijuana exposure in pregnancy were reviewed and support some degree of developmental disruption, including an increased risk of fetal growth restriction and adverse neurodevelopmental consequences. However, much of the existing prenatal marijuana research was performed in the 1980s, when quantities of THC were lower and the frequency of use was less. Additionally, most human studies are also limited and conflicting as most studies have been observational or retrospective, relying primarily on patient self-report and confounded by polysubstance abuse and small sample sizes, precluding determination of a causal effect specific for marijuana. Given the paucity of evidence, it is currently recommended to avoid using marijuana while pregnant or when breastfeeding.

Conclusion and Relevance

There is a critical need for research on effects in pregnancy using present-day THC doses. Once the adverse perinatal effects of marijuana exposure are identified and well characterized, patient education and antenatal surveillance can be developed to predict and mitigate its impact on maternal and fetal health.

Preconception and prenatal cannabis use and the risk of behavioural and emotional problems in the offspring; a multi-informant prospective longitudinal study

BACKGROUND

Studies of the long-term consequences of maternal cannabis use on child development beyond the neonatal period are sparse. In the current study, we use a multi-information approach to assess the association of prenatal cannabis exposure and child behavioural and emotional functioning. To explore the possible causal nature of the association, we investigated whether maternal tobacco and paternal cannabis use during pregnancy were also associated with child problems.

METHODS

The study population included children of a population-based birth cohort in The Netherlands (n = 5903). Information on parental cannabis use was collected using questionnaires; urine of mothers was analysed for the presence of cannabis metabolites. Child behavioural and emotional problems at approximately 7-10 years were measured using validated teacher-, child- and mother-reports.

RESULTS

Our findings show associations of maternal cannabis use during pregnancy with offspring externalising problems (B = 0.53; 95% CI: 0.29-0.77), but not with internalising problems (B = -0.10; 95% CI: -0.31-0.11). However, maternal cannabis use before pregnancy was also associated with offspring externalising problems (B = 0.27; 95% CI: 0.02-0.52). Further, cannabis use by the father was associated with child externalising problems (B = 0.36; 95% CI: 0.22-0.49) but not internalising problems.

CONCLUSIONS

Prenatal exposure to maternal cannabis use is specifically associated with offspring behavioural problems, but not emotional problems. This association is probably not due to an effect of intrauterine cannabis exposure on fetal development, because both maternal and paternal cannabis exposure during pregnancy were related to offspring externalising problems. Our findings suggest that the association can be explained through residual confounding, most likely through shared genetic vulnerabilities for parental cannabis use and offspring behavioural problems.

Marijuana Use in Pregnancy and While Breastfeeding

The prevalence and perceived safety of marijuana use in pregnancy are increasing with expanding legalization. Marijuana crosses the placenta and passes into breast milk, resulting in fetal and neonatal exposure. Many women cite medical reasons for prenatal marijuana use such as nausea and vomiting of pregnancy, anxiety, and chronic pain. The scientific literature regarding marijuana in pregnancy is mixed, resulting in confusion among practitioners as to how to counsel women about risks of use. In addition, there is a paucity of literature related to marijuana use and breastfeeding. Existing pregnancy studies are predominantly retrospective cohorts with a reliance on self-report for ascertainment of exposure, which underestimates use. Many studies fail to adjust for important confounding factors such as tobacco use and sociodemographic differences. Despite the limitations of the existing evidence, there are animal and human data suggesting potential harm of cannabis use. The harms are biologically plausible given the role of the endocannabinoid system in pregnancy implantation, placentation, and fetal neurologic development. Two recent systematic reviews and meta-analyses found an association between marijuana use and adverse perinatal outcomes, especially with heavy marijuana use. In addition, three longitudinal cohort studies demonstrate a possible effect of prenatal marijuana exposure on long-term neurobehavioral outcomes. Marijuana use may be associated with growth restriction, stillbirth, spontaneous preterm birth, and neonatal intensive care unit admission. Therefore, women should be advised to refrain from using marijuana during pregnancy and lactation.

Zebrafish as an alternative method for determining the embryo toxicity of plant products: a systematic review

The toxicological assessment of plant products and pharmaceutical chemicals is a necessary requirement to ensure that all compounds are safe to be exposed to humans. Many countries are trying to reduce the use of animals; thus, alternative techniques, such as ex vivo tests, in vitro assays, and ex uteri embryos, are used. Toxicological assays using zebrafish embryos are an advantageous technique because they are transparent, have rapid embryonic development, and do not require invasive techniques. This paper comprehensively reviews how toxicity testing with plant products is conducted in zebrafish embryos. The search terms zebra fish, Danio rerio, zebrafish, zebra danio, Brachydanio rerio, zebrafish, and embryos were used to search for English-language articles in PUBMED, SCOPUS, and WEB OF SCIENCE. Twelve articles on plant product toxicity studies using zebrafish were selected for reading and analysis. After analyzing the articles and comparing with results in mammals, it was possible to prove the similarity among the results and thus corroborate the further development of zebrafish as a valid tool in toxicity tests.

Marijuana Use During Pregnancy and Breastfeeding: Implications for Neonatal and Childhood Outcomes

Marijuana is one of the most widely used substances during pregnancy in the United States. Emerging data on the ability of cannabinoids to cross the placenta and affect the development of the fetus raise concerns about both pregnancy outcomes and long-term consequences for the infant or child. Social media is used to tout the use of marijuana for severe nausea associated with pregnancy. Concerns have also been raised about marijuana use by breastfeeding mothers. With this clinical report, we provide data on the current rates of marijuana use among pregnant and lactating women, discuss what is known about the effects of marijuana on fetal development and later neurodevelopmental and behavioral outcomes, and address implications for education and policy.

Therapeutic potential of medicinal marijuana: an educational primer for health care professionals

With the proposed Canadian July 2018 legalization of marijuana through the Cannabis Act, a thorough critical analysis of the current trials on the efficacy of medicinal marijuana (MM) as a treatment option is necessary. This review is particularly important for primary care physicians whose patients may be interested in using MM as an alternative therapy. In response to increased interest in MM, Health Canada released a document in 2013 for general practitioners (GPs) as an educational tool on the efficacy of MM in treating some chronic and acute conditions. Although additional studies have filled in some of the gaps since the release of the Health Canada document, conflicting and inconclusive results continue to pose a challenge for physicians. This review aims to supplement the Health Canada document by providing physicians with a critical yet concise update on the recent advancements made regarding the efficacy of MM as a potential therapeutic option. An update to the literature of 2013 is important given the upcoming changes in legislation on the use of marijuana. Also, we briefly highlight the current recommendations provided by Canadian medical colleges on the parameters that need to be considered prior to authorizing MM use, routes of administration as well as a general overview of the endocannabinoid system as it pertains to cannabis. Lastly, we outline the appropriate medical conditions for which the authorization of MM may present as a practical alternative option in improving patient outcomes as well as individual considerations of which GPs should be mindful. The purpose of this paper is to offer physicians an educational tool that provides a necessary, evidence-based analysis of the therapeutic potential of MM and to ensure physicians are making decisions on the therapeutic use of MM in good faith.

Prenatal Cannabis and Tobacco Exposure in Relation to Brain Morphology: A Prospective Neuroimaging Study in Young Children

BACKGROUND

Cannabis use during pregnancy has been associated with negative behavioral outcomes and psychopathology in offspring. However, there has been little research evaluating alterations in brain structure as a result of maternal cannabis use. In this prospective study, we investigated the association between prenatal cannabis exposure and brain morphology in young children.

METHODS

We matched 96 children prenatally exposed to tobacco only (without cannabis) with 113 unexposed control subjects on the basis of age and gender and subsequently selected 54 children exposed to prenatal cannabis (mostly combined with tobacco exposure). These children (aged 6 to 8 years) were part of a population-based study in the Netherlands, the Generation R Study, and were followed from pregnancy onward. We assessed brain volumetric measures and cortical thickness in magnetic resonance imaging scans using FreeSurfer. We performed vertexwise analyses in FreeSurfer and linear regression analyses adjusting for relevant covariates using Statistical Package for the Social Sciences.

RESULTS

Prenatal cannabis exposure was not associated with global brain volumes, such as total brain volume, gray matter volume, or white matter volume. However, prenatal cannabis exposure was associated with differences in cortical thickness: compared with nonexposed control subjects, cannabis-exposed children had thicker frontal cortices. Prenatal tobacco exposure compared with nonexposed control subjects was associated with cortical thinning, primarily in the superior frontal and superior parietal cortices.

CONCLUSIONS

Our findings suggest an association between prenatal cannabis exposure and cortical thickness in children. Further research is needed to explore the causal nature of this association.

Prenatal exposure to cannabis and maternal and child health outcomes: a systematic review and meta-analysis

OBJECTIVE

To assess the effects of use of cannabis during pregnancy on maternal and fetal outcomes.

DATA SOURCES

7 electronic databases were searched from inception to 1 April 2014. Studies that investigated the effects of use of cannabis during pregnancy on maternal and fetal outcomes were included.

STUDY SELECTION

Case-control studies, cross-sectional and cohort studies were included.

DATA EXTRACTION AND SYNTHESIS

Data synthesis was undertaken via systematic review and meta-analysis of available evidence. All review stages were conducted independently by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Maternal, fetal and neonatal outcomes up to 6 weeks postpartum after exposure to cannabis. Meta-analyses were conducted on variables that had 3 or more studies that measured an outcome in a consistent manner. Outcomes for which meta-analyses were conducted included: anaemia, birth weight, low birth weight, neonatal length, placement in the neonatal intensive care unit, gestational age, head circumference and preterm birth.

RESULTS

24 studies were included in the review. Results of the meta-analysis demonstrated that women who used cannabis during pregnancy had an increase in the odds of anaemia (pooled OR (pOR)=1.36: 95% CI 1.10 to 1.69) compared with women who did not use cannabis during pregnancy. Infants exposed to cannabis in utero had a decrease in birth weight (low birth weight pOR=1.77: 95% CI 1.04 to 3.01; pooled mean difference (pMD) for birth weight=109.42 g: 38.72 to 180.12) compared with infants whose mothers did not use cannabis during pregnancy. Infants exposed to cannabis in utero were also more likely to need placement in the neonatal intensive care unit compared with infants whose mothers did not use cannabis during pregnancy (pOR=2.02: 1.27 to 3.21).

CONCLUSIONS AND RELEVANCE

Use of cannabis during pregnancy may increase adverse outcomes for women and their neonates. As use of cannabis gains social acceptance, pregnant women and their medical providers could benefit from health education on potential adverse effects of use of cannabis during pregnancy.

Marijuana use in pregnancy and lactation: a review of the evidence

With the legalization of recreational marijuana in many states, we anticipate more women will be using and self-reporting marijuana use in pregnancy. Marijuana is the most common illicit drug used in pregnancy, with a prevalence of use ranging from 3% to 30% in various populations. Marijuana freely crosses the placenta and is found in breast milk. It may have adverse effects on both perinatal outcomes and fetal neurodevelopment. Specifically, marijuana may be associated with fetal growth restriction, stillbirth, and preterm birth. However, data are far from uniform regarding adverse perinatal outcomes. Existing studies are plagued by confounding by tobacco and other drug exposures as well as sociodemographic factors. In addition, there is a lack of quantification of marijuana exposure by the trimester of use and a lack of corroboration of maternal self-report with biological sampling, which contributes to the heterogeneity of study results. There is an emerging body of evidence indicating that marijuana may cause problems with neurological development, resulting in hyperactivity, poor cognitive function, and changes in dopaminergic receptors. In addition, contemporary marijuana products have higher quantities of delta-9-tetrahydrocannabinol than in the 1980s when much of the marijuana research was completed. The effects on the pregnancy and fetus may therefore be different than those previously seen. Further research is needed to provide evidence-based counseling of women regarding the anticipated outcomes of marijuana use in pregnancy. In the meantime, women should be advised not to use marijuana in pregnancy or while lactating.

Long-term consequences of perinatal and adolescent cannabinoid exposure on neural and psychological processes

Marihuana is the most widely consumed illicit drug, even among adolescents and pregnant women. Given the critical developmental processes that occur in the adolescent and fetal nervous system, marihuana consumption during these stages may have permanent consequences on several brain functions in later adult life. Here, we review what is currently known about the long-term consequences of perinatal and adolescent cannabinoid exposure. The most consistent findings point to long-term impairments in cognitive function that are associated with structural alterations and disturbed synaptic plasticity. In addition, several neurochemical modifications are also evident after prenatal or adolescent cannabinoid exposure, especially in the endocannabinoid, glutamatergic, dopaminergic and opioidergic systems. Important sexual dimorphisms are also evident in terms of the long-lasting effects of cannabinoid consumption during pregnancy and adolescence, and cannabinoids possibly have a protective effect in adolescents who have suffered traumatic life challenges, such as maternal separation or intense stress. Finally, we suggest some future research directions that may encourage further advances in this exciting field.

The effects of prenatal cannabis exposure on fetal development and pregnancy outcomes: a protocol

INTRODUCTION

The effects of exposure to marijuana in utero on fetal development are not clear. Given that the recent legislation on cannabis in the US is likely to result in increased use, there is a need to assess the effects of prenatal cannabis exposure on fetal development and pregnancy outcomes. The objective of this review is to assess the effects of prenatal exposure to cannabis on pregnancy outcomes (including maternal and child outcomes).

METHODS AND ANALYSES

Major databases will be searched from inception to the latest issue, with the aim of identifying studies that reported the effects of prenatal exposure to cannabis on fetal development and pregnancy outcomes. Two investigators will independently review all titles and abstracts to identify potential articles. Discrepancies will be resolved by repeated review, discussion and consensus. Study quality assessment will be undertaken, using standard protocols. To qualify for inclusion, studies must report at least one maternal or neonatal outcome post partum. Cross-sectional, case-control, cohort and randomised controlled trials published in English will be included. In order to rule out the effects of other drugs that may affect fetal development and pregnancy outcomes, studies will only be included if they report outcomes of prenatal exposure to cannabis while excluding other illicit substances. Data from eligible studies will be extracted, and data analysis will include a systematic review and critical appraisal of evidence, and meta-analysis if data permit. Meta-analysis will be conducted if three or more studies report comparable statistics on the same outcome.

ETHICS AND DISSEMINATION

The review which will result from this protocol has not already been conducted. Preparation of the review will follow the procedures stated in this protocol, and will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Ethical approval of data will not be required since the review will use data that are already available in the public domain through published articles and other reports.

It's not your mother's marijuana: effects on maternal-fetal health and the developing child

Pro-marijuana advocacy efforts exemplified by the "medical" marijuana movement, coupled with the absence of conspicuous public health messages about the potential dangers of marijuana use during pregnancy, could lead to greater use of today's more potent marijuana, which could have significant short- and long-term consequences. This article reviews the current literature regarding the effects of prenatal marijuana use on the pregnant woman and her offspring.

Neuronal substrates and functional consequences of prenatal cannabis exposure

Cannabis remains one of the world's most widely used substance of abuse amongst pregnant women. Trends of the last 50 years show an increase in popularity in child-bearing women together with a constant increase in cannabis potency. In addition, potent herbal "legal" highs containing synthetic cannabinoids that mimic the effects of cannabis with unknown pharmacological and toxicological effects have gained rapid popularity amongst young adults. Despite the surge in cannabis use during pregnancy, little is known about the neurobiological and psychological consequences in the exposed offspring. In this review, we emphasize the importance of maternal programming, defined as the intrauterine presentation of maternal stimuli to the foetus, in neurodevelopment. In particular, we focus on cannabis-mediated maternal adverse effects, resulting in direct central nervous system alteration or sensitization to late-onset chronic and neuropsychiatric disorders. We compare clinical and preclinical experimental studies on the effects of foetal cannabis exposure until early adulthood, to stress the importance of animal models that permit the fine control of environmental variables and allow the dissection of cannabis-mediated molecular cascades in the developing central nervous system. In sum, we conclude that preclinical experimental models confirm clinical studies and that cannabis exposure evokes significant molecular modifications to neurodevelopmental programs leading to neurophysiological and behavioural abnormalities.

Prenatal cannabis exposure and infant outcomes: overview of studies

Accumulating evidence from both human and preclinical studies indicates maternal substance use during pregnancy can affect fetal development, birth weight and infant outcomes. Thus, the prenatal period can be regarded as an important and potentially sensitive period of development. In this manuscript, an updated overview of studies on prenatal cannabis exposure in humans is presented, including recent studies conducted within the Generation R study. Findings on fetal growth, birth outcomes, early neonatal behavior and infant behavior and cognitive development are discussed in detail. Preclinical evidence and potential mechanisms are described as well, and recommendations for future studies are provided. It is concluded that evidence seems to suggest that fetal development is affected by prenatal maternal cannabis use, while findings on effects on infant behavior or cognition are inconsistent. Beyond infancy, subtle differences may be found in specific cognitive or behavioral outcomes, although replication studies in which pregnant women and their fetuses are exposed to current and probably higher levels of Δ9-tetrahydrocannabinol and novel designs are needed to come to firm conclusions.

Cannabis use during pregnancy in France in 2010

OBJECTIVE

The aim was to estimate the proportion of women who reported cannabis use during pregnancy, to analyse the demographic and social characteristics of users, and the link between cannabis use and either preterm or small-for-gestational-age birth.

DESIGN

Data were obtained from interviews of a representative sample of women giving birth in France in 2010 in the days after delivery, and from their medical records.

SETTING

All maternity units in France.

SAMPLE

The analysis includes women with live singleton births in metropolitan France who responded to the question about cannabis use during pregnancy: in total, 13 545 women.

METHODS

The percentage of cannabis users during pregnancy was estimated, and variations according to social characteristics were described. Logistic regression analyses were used to investigate any associations between cannabis use and preterm birth or small-for-gestational-age status.

MAIN OUTCOME MEASURES

Percentage of cannabis use, preterm birth rate, and small-for-gestational-age rate.

RESULTS

In all, 1.2% of women reported having used cannabis during pregnancy. This percentage was higher among younger women, women living alone, or women who had a low level of education or low income. It was also associated with tobacco use and drinking alcohol. Cannabis users had higher rates of spontaneous preterm births: 6.4 versus 2.8%, for an adjusted odds ratio (aOR) of 2.15 (95% CI 1.10-4.18). The corresponding aOR was 2.64 (95% CI 1.12-6.22) among tobacco smokers and 1.22 (95% CI 0.29-5.06) among non-tobacco smokers.

CONCLUSIONS

Although the reported rate of cannabis use during pregnancy in France is low, efforts should be continued to inform women and healthcare providers about the potential consequences of its use.

Cannabis and psychosis: Neurobiology

Cannabis is a known risk factor for schizophrenia, although the exact neurobiological process through which the effects on psychosis occur is not well-understood. In this review, we attempt to develop and discuss a possible pathway for the development of psychosis. We examine the neurobiological changes due to cannabis to see if these changes are similar to those seen in schizophrenic patients the findings show similarities; however, these mere similarities cannot establish a 'cause-effect' relationship as a number of people with similar changes do not develop schizophrenia. Therefore, the 'transition-to-psychosis' due to cannabis, despite being a strong risk factor, remains uncertain based upon neurobiological changes. It appears that other multiple factors might be involved in these processes which are beyond neurobiological factors. Major advances have been made in understanding the underpinning of marijuana dependence, and the role of the cannabinoid system, which is a major area for targeting medications to treat marijuana withdrawal and dependence, as well as other addictions is of now, it is clear that some of the similarities in the neurobiology of cannabis and schizophrenia may indicate a mechanism for the development of psychosis, but its trajectories are undetermined.

Cardiovascular and metabolic influences of fetal smoke exposure

Many epidemiological studies showed associations of low birth weight with cardiovascular disease, type 2 diabetes and obesity. The associations seem to be consistent and stronger among subjects with a postnatal catch up growth. It has been suggested that developmental changes in response to adverse fetal exposures might lead to changes in the fetal anatomy and physiology. These adaptations may be beneficial for short term, but may lead to common diseases in adulthood. Maternal smoking during pregnancy is one of the most important adverse fetal exposures in Western countries, and is known to be associated with a 150-200 g lower birth weight. An accumulating body of evidence suggests that maternal smoking during pregnancy might be involved in pathways leading to both low birth weight and common diseases, including cardiovascular disease, type 2 diabetes and obesity, in adulthood. In this review, we discuss epidemiological studies focused on the associations of maternal smoking with fetal growth and development and cardiovascular and metabolic disease in later life. We also discuss potential biological mechanisms, and challenges for future epidemiological studies.

Cardiovascular and metabolic influences of fetal smoke exposure

Many epidemiological studies showed associations of low birth weight with cardiovascular disease, type 2 diabetes and obesity. The associations seem to be consistent and stronger among subjects with a postnatal catch up growth. It has been suggested that developmental changes in response to adverse fetal exposures might lead to changes in the fetal anatomy and physiology. These adaptations may be beneficial for short term, but may lead to common diseases in adulthood. Maternal smoking during pregnancy is one of the most important adverse fetal exposures in Western countries, and is known to be associated with a 150–200 g lower birth weight. An accumulating body of evidence suggests that maternal smoking during pregnancy might be involved in pathways leading to both low birth weight and common diseases, including cardiovascular disease, type 2 diabetes and obesity, in adulthood. In this review, we discuss epidemiological studies focused on the associations of maternal smoking with fetal growth and development and cardiovascular and metabolic disease in later life. We also discuss potential biological mechanisms, and challenges for future epidemiological studies.

The Generation R Study: design and cohort update 2010

The Generation R Study is a population-based prospective cohort study from fetal life until young adulthood. The study is designed to identify early environmental and genetic causes of normal and abnormal growth, development and health during fetal life, childhood and adulthood. The study focuses on four primary areas of research: (1) growth and physical development; (2) behavioural and cognitive development; (3) diseases in childhood; and (4) health and healthcare for pregnant women and children. In total, 9,778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. General follow-up rates until the age of 4 years exceed 75%. Data collection in mothers, fathers and preschool children included questionnaires, detailed physical and ultrasound examinations, behavioural observations, and biological samples. A genome wide association screen is available in the participating children. Regular detailed hands on assessment are performed from the age of 5 years onwards. Eventually, results forthcoming from the Generation R Study have to contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.