Table 1. Summary of Included Studies.

Source	Study design	Country	Study groups and sample
Bailey et al,24 2020	Cohort study	United States	Newborns exposed to marijuana: n = 531; control group: n = 531
Conner et al,25 2015	Cohort study	United States	Marijuana use: n = 680; no marijuana use: n = 7458
Conner et al,26 2016	Cohort study	United States	Marijuana use: n = 76; no marijuana use: n = 115
Fried et al,27 1984	Cohort study	Canada	Irregular marijuana use: n = 48; moderate use: n = 18; heavy use: n = 18; no marijuana use: n = 499
Hayes et al,28 1988	Cohort study	Jamaica	Irregular marijuana users: n = 11; moderate use: n = 11; heavy use: n = 8; no marijuana use: n = 25
Hoffman et al,20 2019	Cohort study	United States	Marijuana only at conception: n = 26; marijuana at <10 wk gestation: n = 13; marijuana at ≥10 wk gestation: n = 25; no marijuana use: n = 98
Linn et al,29 1983	Cohort study	United States	No marijuana use: n = 11 178; occasional use: n = 880; weekly use: n = 228; daily use: n = 137
Mark et al,30 2015	Cohort study	United States	Marijuana negative: n = 280; marijuana positive: n = 116
Metz et al,31 2017	Cohort study	United States	Marijuana use: n = 48; no marijuana use: n = 1562
Rodriguez et al,21 2019	Cohort study	United States	Marijuana use: n = 211; no marijuana use: n = 995
Shiono et al,32 1995	Cohort study	United States	Marijuana use: n = 822; no marijuana use: n = 6648
Stein et al,33 2019	Cohort study	United States	Marijuana use: n = 430; no marijuana use: n = 4154
Straub et al,34 2019	Cohort study	United States	Marijuana negative: n = 4075; marijuana positive: n = 1268
Warshak et al,35 2015	Cohort study	United States	Marijuana use: n = 361; no marijuana use: n = 6107
Witter et al,36 1990	Cohort study	United States	Marijuana use: n = 417; no marijuana use: n = 7933
Zuckerman et al,37 1989	Cohort study	United States	Marijuana use: n = 202; no marijuana use: n = 895