Study says: "... we modeled PCE by administering THC (2 mg per kg, subcutaneously (s.c.) once daily) to rat dams during pregnancy (from gestational day (GD) 5 until GD20). This low THC dose does not recapitulate behavioral responses in the can-nabinoid tetrad assay or elicits cannabinoid tolerance after repeated administration, hence it represents a mild insult without any substantial direct impact on maternal behavior. ... In terms of human consumption, this dose is equivalent to THC content in mild cannabis cigarettes (joints) (5%), since the average THC content in illicit cannabis preparations has significantly increased in the last two decades (from ~4% to ~12%)."