Table 1.
Prenantal marijuana exposure studies in humans.
| Age† | Cohort‡ | Category | Results/outcomes | Exposure details | Ref. |
|---|---|---|---|---|---|
| Fetus | |||||
| 17-22 GW | – | Growth | Reduced foot length and bodyweight | ≥0.4 J/day | [48] |
| 18-22 GW | – | Dopamine signaling | Decreased D2 mRNA in amygdala of males only | ≥0.4 J/day | [152] |
| 18-22 GW | – | Endorphin signaling | Decreased opioid peptide (PENK) and receptor (κ) in caudal putamen and thalamus, respectively; increased opioid receptor (μ) in the amygdala | – | [74] |
| Neonatal | |||||
| Neonatal | OPPS | Neurobehavior | Increased tremors, exaggerated startles and diminished responsiveness to light | – | [46] |
| Neonata | MHPCD | Growth | Decreased body length | ≥1 J/day, first | [49] |
| Neonata | – | Growth | No effect on birthweight, length or gestational age | Trim | [54] |
| Neonatal | VIPS | Neurobehavior Growth | No effectNo effect on birthweight, preterm delivery or abruptio placentae | – | [35] |
| Neonata | – | Growth | No effect on birthweight, length or gestational age | – | [52] |
| Behavior | More irritable, less responsive to calming, increased jitters and startles | – | |||
| Neonatal | NBDPS | Growth | No effect on birthweight, gestational age or preterm delivery | – | [40] |
| 1 mo | – | Behavior | Less irritable, more alert, more robust autonomic and motor systems, more autonomically stable and increased orientation | ≥2.86 J/day | [54] |
| Toddler | |||||
| 8 mo | MHPCD | Growth | No effect | – | [49] |
| 9 mo | MHPCD | Mental/motor skills | Delayed mental development | ≥1 J/day, third Trim | [26] |
| 1 y | OPPS | Mental/motor skills | No effect | – | [55] |
| 1 y | – | Mental/motor skills | Decreased motor scores, no effect on mental development | ≥0.5 J/day, first Trim | [149] |
| 19 mo | MHPCD | Mental/motor skills | No effect | – | [26] |
| 2 y | OPPS | Mental/motor skills | No effect | – | [55] |
| 3 y | MHPCD | Intelligence | No effect on overall IQ for entire cohort | – | [57] |
| Cognition | For African–Americans: decrease in short-term memory and verbal reasoning | ≥1 J/day, first/second Trim | |||
| 3 y | MHPCD | Sleep and arousal | Lowered sleep efficiency, more nocturnal arousals and more awake time after sleep onset | – | [153] |
| Childhood | |||||
| 4 y | – | Sustained attention | Increased number of omission errors | First Trim | [45] |
| 4 y | MHPCD | Motor skills | No effect on balance and coordination skills | – | [154] |
| 5-6 y | OPPS | Cognition and language | No effect | – | [155] |
| 6 y | MHPCD | Growth | No effect | – | [156] |
| 6 y | OPPS | Memory | No effect | ≥0.86 J/day | [58] |
| Attention | Increased number of omission errors | ||||
| Behavior | Described as more impulsive and hyperactive | ||||
| 6 y | MHPCD | Impulsivity | Increase in errors of ommission | Second Trim | [60] |
| Sustained attention | Decrease in errors of omission | ||||
| 6 y | MHPCD | Intelligence | Lower overall composite score | ≥1 J/day, first/second Trim | [59] |
| Cognition | Lower verbal reasoning, quantitative reasoning and short-term memory | ||||
| 9–12 y | OPPS | Reading and language | No effect in regards to reading or language | – | [68] |
| 9–12 y | OPPS | Intelligence | No effect in terms of full scale IQ | – | [63] |
| Executive function | Impulse control and visual hypothesis aspects are negatively impacted | > 0.86 J/day | |||
| Adolescence | |||||
| 10 y | MHPCD | Behavior and emotion | Increased inattention, hyperactivity, impulsivity, delinquent behavior and externalizing problems | ≥0.4 J/day, | [62] |
| Behavior and emotion | Fewer internalizing problems, although not correlated with teacher's report | first/third Trim ≥0.4 J/day, | |||
| 10 y | MHPCD | Learning and memory | Predicted lower scores in design memory and screening index | second Trim ≥0.89 J/day, | [47] |
| Sustained attention | Increase in errors of commission | first Trim ≥0.89 J/day, | |||
| 10 y | MHPCD | Depression | Increased levels of depressive symptoms | second Trim >0.89 J/day, | [64] |
| 12y | – | Psychotic symptoms | No effect | first/third Trim | [66] |
| 10–14 y | – | Volumetric MRI | No effect on cortical gray matter volume, white matter volume, cerebral spinal fluid or parenchymal volume | – | [69] |
| 10 y | MHPCD | Behavior and cognition | Negatively associated with depressive symptoms, IQ, learning and memory | ≥0.89 J/day, first/second Trim | [61] |
| 14 y | Delinquent behaviors | Increased delinquent behaviors | ≥0.89 J/day | ||
| 13–16 y | OPPS | Sustained attention | Decreased stability of attention over time | ≥0.86 J/day | [71] |
| 13–16 y | OPPS | Growth | No changes in weight, height or puberty symptoms | – | [157] |
| 13–16 y | OPPS | Visual memory | Lower scores in abstract designs and Peabody spelling | ≥0.86 J/day | [27] |
| 16y | MHPCD | Fine motor coordination | Various light deficits in processing speed and interhemispheric motor coordination | >2 J/mo | [158] |
| Visual-motor coordination | Slight increase in visual-motor coordination | ||||
| Young adult | |||||
| 18-22y | OPPS | Response inhibition | Slightly more errors of commission | – | [72] |
| Response inhibition by fMRI | Increased bilateral PFC activity, right premotor cortex activity; decreased activity in left cerebellum | – | |||
| Intelligence | No effect | – | |||
| Working memory by fMRI | Increased activity in left medial PFC, inferior frontal gyrus and left cerebellum; decreased activity in right brain regions - medial PFC, DLPFC and ventrolateral PFC | – | [73] | ||
†
Exposed offspring study age.
‡
Specified conditions of prenatal exposure.
DLPFC: Dorsolateral prefrontal cortex; GW: Gestation week(s); J: Joint; MHPCD: Maternal Health Practices and Child Development Project; mo: Month(s); NBDPS: National Birth Defects Prevention Study; OPPS: Ottawa Prenatal Prospective Study; PENK: Proenkephalin; PFC: Prefrontal cortex; Trim: Trimester; VIPS: Vaginal Infections and Prematurity Study; y: Year(s).