Table 1: Mean motor development score corresponding with cannabis exposure during gestation and lactation [23].

Motor Development PDI

Days of infant Cannabis exposureMean

Trimester one
0105 ( )
1 to 4499 ( )
45 to 9093 ( )

Trimester two
0102 ( )
1 to 44104 ( )
45 to 9094 ( )

Trimester three
0101 ( )
1 to 44107 ( )
45 to 9094 ( )

Lactation month one
0102 ( )
1 to 44106 ( )
45 to 9090 ( )

Lactation month three
0102 ( )
1 to 44103 ( )
45 to 9097 ( )

Motor developmental scores (Psychomotor Development Index, PDI) were from Bayley Scales of Infant Development. During the first trimester, PDI decreased with increasing cannabis exposure (test for linear trend, ). During the first lactation month, mean PDI for the higher exposure group was lower than the PDI for the no or low exposure groups (one-way ANOVA ).