Table 2.
Sample Characteristics by Level of First Trimester Marijuana Use
| Maternal Marijuana Use | |||||
|---|---|---|---|---|---|
| No usea (n=347) | Light to moderate useb (n=165) | Heavy usec (n=77) | p-valued | Effect sizee | |
| Maternal Characteristics at the First Trimester Visit | |||||
| Age (mean years) | 23.3 | 22.6 | 22.8 | 0.16 | 0.006 |
| Race (% African American) | 45.5 | 52.7 | 75.3 | <0.001 | 0.196 |
| Education (mean years) | 11.8 | 11.8 | 11.7 | 0.760 | 0.001 |
| Marital status (% married) | 37.5 | 27.3 | 18.2 | 0.001 | 0.150 |
| Employment status (% in school or working outside the home) | 25.4 | 30.9 | 14.3 | 0.022 | 0.114 |
| Household income (%<US$400/month) | 57.1 | 64.6 | 73.3 | 0.020 | 0.117 |
| Depression (mean CES-D score) | 20.8 | 21.1 | 21.3 | 0.894 | <0.001 |
| Anxiety (mean STPI score) | 17.6 | 17.9 | 18.0 | 0.627 | 0.002 |
| Hostility (mean STPI score) | 18.3 | 19.1 | 19.8 | 0.063 | 0.009 |
| Any alcohol use (%) | 55.3 | 78.2 | 74.0 | <0.001 | 0.222 |
| Average daily volume of alcohol | 0.40 | 0.75 | 0.78 | <0.001 | 0.027 |
| Any cigarette use (%) | 47.3 | 60.0 | 64.9 | 0.002 | 0.144 |
| Average daily cigarettes | 7.7 | 8.6 | 9.4 | 0.410 | 0.003 |
| Any cocaine use (%) | 1.7 | 5.4 | 9.1 | 0.003 | 0.139 |
| Any other drug use (%) | 6.9 | 9.7 | 15.6 | 0.047 | 0.102 |
| Offspring Characteristics at Birth | |||||
| Gender (% male) | 47.8 | 47.3 | 44.2 | 0.842 | 0.024 |
| Gestational age (mean weeks) | 39.7 | 39.9 | 39.8 | 0.460 | 0.003 |
| Preterm birth (% <37 weeks) | 8.4 | 8.5 | 6.5 | 0.849 | 0.024 |
| Birth weight (mean kg) | 3.2 | 3.2 | 3.1 | 0.172 | 0.006 |
| Low birth weight (%<2500g) | 9.5 | 10.9 | 10.4 | 0.880 | 0.021 |
| Offspring Characteristics at 22 Years | |||||
| Age (mean years) | 22.9.8 | 22.8 | 22.7.0 | 0.020 | 0.013 |
| Race (% African American) | 51.6 | 55.1 | 79.2 | <0.001 | 0.183 |
| Education (mean years) | 12.8 | 12.9 | 12.4 | 0.056 | 0.010 |
| Personal income (mean US$/month) | 1006 | 969 | 800 | 0.308 | 0.006 |
| Work status (% working or in school) | 61.9 | 63.6 | 51.9 | 0.195 | 0.075 |
| Marital status (% married) | 5.5 | 7.9 | 3.9 | 0.403 | 0.056 |
| Lives with mother or caregiver (%) | 37.2 | 30.3 | 33.8 | 0.306 | 0.063 |
| Has at least one child (%) | 36.0 | 34.6 | 45.4 | 0.231 | 0.071 |
| Family history of alcohol or drug problems (%) | 45.4 | 46.3 | 54.6 | 0.341 | 0.061 |
| Initiated cigarettes (%) | 80.4 | 83.0 | 84.4 | 0.618 | 0.040 |
| Past-year cigarette use (%) | 41.2 | 43.6 | 53.2 | 0.156 | 0.080 |
| Average daily cigarettes | 4.0 | 4.6 | 5.5 | 0.138 | 0.005 |
| Initiated alcohol (%) | 98.8 | 100.0 | 98.7 | 0.372 | 0.058 |
| Past-year alcohol use (%) | 92.2 | 93.3 | 92.2 | 0.898 | 0.019 |
| Average daily volume of alcohol | 1.5 | 1.8 | 1.6 | 0.124 | 0.005 |
| Initiated marijuana (%) | 79.2 | 87.3 | 90.9 | 0.011 | 0.124 |
| Past-year marijuana use (%) | 44.1 | 56.9 | 62.3 | 0.002 | 0.147 |
| Average daily joints of marijuana | 0.70 | 0.67 | 1.70 | <0.001 | 0.028 |
| Past-year cocaine use (%) | 5.5 | 7.9 | 9.1 | 0.383 | 0.057 |
| Past-year other illicit drug use (%) | 12.1 | 14.6 | 19.5 | 0.222 | 0.072 |
a
Zero joints per day
b
Less than one joint per day
c
One or more joints per day
d
ANOVA for continuous variables, Kruskal-Wallis test for skewed variables, χ2 test for dichotomous variables
e
Eta2 for continuous variables, Cramer’s V for dichotomous variables; absolute value reported