Prenatal tobacco and cannabis co-exposure and offspring obesity development from birth to mid-childhood

Impact of prenatal exposure to delta 9-tetrahydrocannabinol and cannabidiol on birth size and postnatal growth trajectories

BACKGROUND

Prenatal exposure to cannabis (or more specifically, delta 9-tetrahydrocannabinol [Δ9-THC]) has been consistently linked to low birthweight. Animal models further show that Δ9-THC is associated with rapid postnatal growth. Whether this association is modified by breastfeeding is unknown.

METHODS

In this exploratory study, we followed 128 mother-child pairs through 3 years. Urinary Δ9-THC and cannabidiol (CBD) were measured mid-gestation. Generalized linear models estimated the associations between Δ9-THC and neonatal body composition. A mixed-effects model estimated the association between Δ9-THC and body mass index (BMI) z-score trajectories. Interaction was assessed by a three-way product term (Δ9-THC × breastmilk months × age).

RESULTS

Fifteen children (12%) had Δ9-THC exposure; three had concomitant CBD exposure. Prenatal exposure to Δ9-THC alone was associated with lower fat mass (-95 g, 95% confidence interval [CI]: -174, -14) and neonatal adiposity (-2.1%; 95% CI: -4.2, -0.4) followed by rapid postnatal growth (0.42 increase in BMI z-score per square root year; 95% CI: 0.12, 0.72). Breastfeeding modified this association (p = 0.04), such that growth was similar for those breastfed for 5 months whereas a shorter duration of breastfeeding was associated with 1.1 higher BMI z-score at 3 years (95% CI: 0.21, 2.05).

CONCLUSIONS

Our study suggests that prenatal exposure to Δ9-THC may alter early-life growth. Breastfeeding may stabilize rapid postnatal growth, but the impact of lactational exposure requires further investigation.

Vaporized Δ9-THC in utero results in reduced birthweight, increased locomotion, and altered wake-cycle activity dependent on dose, sex, and diet in the offspring

AIMS

Preclinical studies have found that chronic ∆9-tetrahydrocannabinol (THC) treatment is directly associated with weight gain when introduced during adolescence and adulthood, but the effect of prenatal THC is unclear. Clinical studies have demonstrated prenatal exposure to THC is a prospective predictor of increased health risks associated with obesity. Our study aims to examine prenatal THC impact on obesity risks in males and females throughout adolescence using a clinically relevant inhalation model.

METHODS

Pregnant rats were exposed to one of the following from gestational day 2 through birth: 10 mg THC, 40 mg THC, or air. Daily 10-min inhalations were conducted in each animal from 0900 to 1200. Offspring from each treatment group were given either a high-fat diet (HFD) or a normal diet (ND). Food and bodyweights were collected daily, while circadian activity, locomotion, and exercise were measured periodically (PND 21-60). Pregnancy weight gain and birth weight were collected to determine early-life developmental effects.

RESULTS

Rats prenatally treated with low-dose THC (LDTHC) generally had lower dark-cycle activity compared with control counterparts, but this altered activity was not observed at the higher dose of THC (HDTHC). In terms of open-field activity, THC doses displayed a general increase in locomotion. In addition, the LDTHC male rats in the ND showed significantly greater exploratory behavior. Prenatal THC had dose-dependent effects on maternal weight gain and birth weight.

CONCLUSIONS

Overall, our findings indicate there are some activity-related and developmental effects of prenatal THC, which may be related to obesity risks later in life.

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.