“In a 2020 review of relevant studies published since the mid-1980s, the authors called out many of these studies for weak methodology. In particular, many researchers had failed to compare the outcomes they were measuring against any kind of a standard that would account for age and parental educational level. (That is: What if the kids of those who used cannabis during pregnancy were born to parents with lower levels of education, which could account for some differences?)
The review authors concluded that overall, “prenatal cannabis exposure is associated with few effects on the cognitive functioning of offspring.” What’s more, they noted, even when abnormalities were identified, almost all were still within the range of normal.”
…
“Despite the imperfect data, Mark suspects the risk of fetal harm with prenatal cannabis use is high enough to support recommending against purely recreational use.
But many aren’t seeking to get high.”