Maternal persistent marijuana use and cigarette smoking are independently associated with shorter gestational age

Fetal Cannabis Exposure and Neonatal Outcomes: A Systematic Review and Meta-Analysis

INTRODUCTION

Current literature addressing fetal cannabis exposure and neonatal outcomes is based on subjective measures with varying levels of significance. This systematic review and meta-analysis determined if neonates with fetal cannabis exposure have an increased odds of being born small for gestational age, low birth weight, admitted to the Neonatal Intensive Care Unit (NICU) immediately after delivery, and/or preterm.

METHODS

To identify relevant articles, we searched five databases using standard search criteria. Two authors used the Newcastle-Ottawa Scale to exclude articles with a high risk of bias. To estimate the combined effect, we calculated pooled odd ratios (OR) with 95% confidence intervals (CI) using the Mantel-Haenszel method for dichotomous data.

RESULTS

Of 3,390 original articles we identified through the search strategy, 13 met the inclusion criteria. This meta-analysis indicates that neonates with fetal cannabis exposure have higher odds of being small for gestational age (OR = 1.79; 95% CI = 1.24-2.59) and/or having a low birth weight (OR = 1.38; 95% CI = 1.05-1.89) compared to neonates without fetal cannabis exposure. The results regarding NICU admission and preterm birth were statistically inconclusive (NICU admission: OR = 1.38, 95% CI = 0.86-2.22; Preterm birth: OR = 1.29, 95% CI = 0.97-1.71). Although the odds ratios for these associations span one suggesting a null relationship, they have an upper bound that may be clinically relevant.

DISCUSSION

Based on these findings, further research, as well as an evaluation of the current public health response, is warranted. Additional research is needed to identify the association between neonatal outcomes and specific nuances of fetal cannabis exposure, such as route of ingestion, frequency of use, dose consumed, and the timing of intrauterine exposure.

Association between maternal cigarette smoking cessation and risk of preterm birth in Western New York

BACKGROUND

Although many studies suggested the benefit of smoking cessation among pregnant women in reducing the risk of preterm birth (PTB), the timing of the effect of the cessation remains inconclusive.

OBJECTIVES

To examine the association of trimester-specific smoking cessation behaviours with PTB risk.

METHODS

We included 199,453 live births in Western New York between 2004 and 2018. Based on self-reported cigarette smoking during preconception and in each trimester, we created six mutually exclusive groups: non-smokers, quitters in each trimester, those who smoked throughout pregnancy, and inconsistent smokers. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using Poisson regression to examine the association between smoking cessation and PTB. Effect modification by illegal drug use, maternal age, race and ethnicity and pre-pregnancy body mass index (BMI) was investigated multiplicatively by ratio of relative risk and additively by relative excess risk due to interaction (RERI).

RESULTS

Overall, 6.7% of women had a PTB; 14.1% smoked throughout pregnancy and 3.4%, 1.8% and 0.8% reported quitting smoking during the first, second and third trimesters, respectively. Compared to non-smokers, third-trimester cessation (RR 1.20, 95% CI 1.01, 1.43) and smoking throughout pregnancy (RR 1.27, 95% CI 1.21, 1.33) were associated with a higher PTB risk, while quitting smoking during the first or second trimester, or inconsistent smoking was not associated with PTB. A positive additive interaction was identified for maternal age and late smoking cessation or smoking throughout pregnancy on PTB risk (RERI 0.17, 95% CI 0.00, 0.36), and a negative interaction was observed for pre-pregnancy BMI ≥30 kg/m2 (ratio of relative risk 0.70, 95% CI 0.63, 0.78; RERI -0.42, 95% CI -0.56, -0.30).

CONCLUSION

Compared to non-smokers, smoking throughout pregnancy and third-trimester smoking cessation are associated with an increased risk of PTB, while quitting before the third trimester may not increase PTB risk.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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..

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.

The Liberalization of Cannabis Possession Laws and Birth Outcomes: A State-Level Fixed Effects Analysis, 2003-2019

As states liberalize their cannabis laws, cannabis use has become more widespread among adults across the United States, including pregnant women. As a result, recent research has investigated the potential effects of prenatal cannabis use on child health, with mixed results. In this study, we investigate the relationship between the liberalization of state-level cannabis possession laws and two birth outcomes indicative of child health: birthweight and gestational age. Drawing on 2003-2019 data from CDC WONDER, the American Community Survey, and multiple legal databases, we use fixed effects models to examine how changes in cannabis policies-moving from a misdemeanor to decriminalized to legalized possession-have influenced state-level averages in birthweight and gestational age and percentages of births classified as low birthweight (<2500g) and preterm (<37 weeks). We account for state-level factors including medical cannabis laws, health-related policies, spending patterns, and demographic characteristics known to influence health. Results indicate that the liberalization of state cannabis possession laws was associated with statistically significant reductions in average birthweight, and to a lesser extent gestational age, with significant effects for subgroups of women by age, race/ethnicity, and risk factors including chronic hypertension and diabetes. However, we did not find increases in the percentage of women with clinically relevant low birthweight or preterm births following cannabis policy liberalization. Although our study does not show substantial changes in adverse birth outcomes, policymakers should be attentive to opportunities to strengthen child health by considering policies that minimize consumption, particularly heavier forms of consumption, by prospective parents.

Prenatal Cannabinoid Exposure: Emerging Evidence of Physiological and Neuropsychiatric Abnormalities

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