Prenatal marijuana exposure and neonatal outcomes: a retrospective cohort study

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

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

Neonatal outcomes associated with in utero cannabis exposure: a population-based retrospective cohort study

BACKGROUND

The full spectrum of associations between in utero cannabis exposure and adverse neonatal outcomes is still unclear.

OBJECTIVE

This study aimed to evaluate the associations between in utero cannabis exposure and neonatal outcomes.

STUDY DESIGN

This population-based retrospective cohort study of singleton births among Kaiser Permanente Northern California members (January 1, 2011-July 31, 2020) included parent-infant dyads in which the pregnant parent was screened for cannabis use as part of standard prenatal care, generally upon entrance into care. Data were ascertained from electronic health records. Generalized estimating equation models were adjusted for sociodemographic characteristics, other non-cannabis prenatal substance use, medical and mental health comorbidities, and adequacy of prenatal care. In utero cannabis exposure was defined as self-reported use since becoming pregnant and/or a positive urine toxicology test for cannabis at any time during pregnancy (yes/no; primary exposure). Frequency of use was self-reported and categorized as daily, weekly, monthly or less, never, or unknown (secondary exposure). Neonatal outcomes included low birthweight, small for gestational age, preterm birth, neonatal intensive care unit admission, and infant respiratory support.

RESULTS

Of 364,924 infants, 22,624 (6.2%) were exposed to cannabis in utero. After adjustment for potential confounders, including in utero exposure to other substances, in utero exposure to cannabis was associated with greater odds of low birthweight (adjusted odds ratio, 1.20; 95% confidence interval, 1.12-1.28), small for gestational age (adjusted odds ratio, 1.24; 95% confidence interval, 1.18-1.30), preterm birth (<37 weeks; adjusted odds ratio, 1.06; 95% confidence interval, 1.00-1.13), and neonatal intensive care unit admission (adjusted odds ratio, 1.06; 95% confidence interval, 1.01-1.11). There was a suggestive association with early preterm birth (<34 weeks; adjusted odds ratio, 1.11; 95% confidence interval, 1.00-1.23; P=.055), but no significant association with respiratory support (adjusted odds ratio, 1.07; 95% confidence interval, 0.97-1.18). Dose-response analysis found an increasing likelihood of low birthweight and small for gestational age with increasing frequency of prenatal cannabis use by the pregnant individual. Sensitivity analyses further supported an increased likelihood of low birthweight and small for gestational age, although associations with other outcomes did not reach statistical significance.

CONCLUSION

In utero cannabis exposure was associated with increased likelihood of low birthweight, small for gestational age, preterm birth, and neonatal intensive care unit admission. Clinicians should counsel individuals who are pregnant or considering pregnancy about the potential adverse neonatal health outcomes associated with prenatal cannabis use.

Maternal Cannabis Use during Lactation and Potential Effects on Human Milk Composition and Production: A Narrative Review

Cannabis use has increased sharply in the last 20 y among adults, including reproductive-aged women. Its recent widespread legalization is associated with a decrease in risk perception of cannabis use during breastfeeding. However, the effect of cannabis use (if any) on milk production and milk composition is not known. This narrative review summarizes current knowledge related to maternal cannabis use during breastfeeding and provides an overview of possible pathways whereby cannabis might affect milk composition and production. Several studies have demonstrated that cannabinoids and their metabolites are detectable in human milk produced by mothers who use cannabis. Due to their physicochemical properties, cannabinoids are stored in adipose tissue, can easily reach the mammary gland, and can be secreted in milk. Moreover, cannabinoid receptors are present in adipocytes and mammary epithelial cells. The activation of these receptors directly modulates fatty acid metabolism, potentially causing changes in milk fatty acid profiles. Additionally, the endocannabinoid system is intimately connected to the endocrine system. As such, it is probable that interactions of exogenous cannabinoids with the endocannabinoid system might modify release of critical hormones (e.g., prolactin and dopamine) that regulate milk production and secretion. Nonetheless, few studies have investigated effects of cannabis use (including on milk production and composition) in lactating women. Additional research utilizing robust methodologies are needed to elucidate whether and how cannabis use affects human milk production and composition.

Prenatal Exposure to Cannabis: Effects on Childhood Obesity and Cardiometabolic Health

PURPOSE OF REVIEW

To consolidate information on the obesogenic and cardiometabolic effects of prenatal exposure to cannabis.

RECENT FINDINGS

A PubMed search strategy updated from January 1, 2014, through 14 June 2023, produced a total of 47 epidemiologic studies and 12 animal studies. Prenatal exposure to cannabis is consistently associated with small for gestational age and low birth weight. After birth, these offspring gain weight rapidly and have increased adiposity and higher glucose (fat mass percentage) in childhood. More preclinical and prospective studies are needed to deepen our understanding of whether these associations vary by sex, dose, timing, and composition of cannabis (e.g., ratio of delta-Δ9-tetrahydrocannabinol [Δ9-THC] to cannabidiol [CBD]). Addressing these gaps may help to solidify causality and identify intervention strategies. Based on the available data, clinicians and public health officials should continue to caution against cannabis use during pregnancy to limit its potential obesogenic and adverse cardiometabolic effects on the offspring.