Table. Baseline Characteristics of Pregnancies Screened for Prenatal Cannabis Use Between January 1, 2012, and December 31, 2019.
| Baseline characteristics | No. (%)a | Standardized differencec | |||
|---|---|---|---|---|---|
| Overall (N = 300 993) | Pre-RCL passage (n = 173 906)b | Post-RCL passage, pre-RCL implementation (n = 47 450)b | Post-RCL implementation (n = 79 637)b | ||
| Age at pregnancy onset, y | |||||
| <25 | 44 437 (14.7) | 28 176 (16.2) | 6397 (13.5) | 9864 (12.4) | 0.10 |
| 25 to <35 | 189 259 (62.9) | 109 021 (62.7) | 30 071 (63.4) | 50 167 (63.0) | |
| ≥35 | 67 297 (22.4) | 36 709 (21.1) | 10 982 (23.1) | 19 606 (24.6) | |
| Race and ethnicityd | |||||
| Hispanic | 78 304 (26.0) | 44 536 (25.6) | 12 365 (26.1) | 21 403 (26.9) | 0.03 |
| Non-Hispanic | |||||
| Asian | 77 799 (25.9) | 44 130 (25.4) | 12 418 (26.2) | 21 251 (26.7) | |
| Black | 19 330 (6.4) | 11 261 (6.5) | 3008 (6.3) | 5061 (6.4) | |
| White | 113 324 (37.6) | 67 227 (38.7) | 17 672 (37.2) | 28 425 (35.7) | |
| Other/multiracial/unknown | 12 236 (4.1) | 6752 (3.9) | 1987 (4.2) | 3497 (4.4) | |
| Gestational age at urine toxicology, mean (SD), wk | 8.9 (4.8) | 9.3 (4.8) | 8.8 (5.0) | 8.1 (4.6) | 0.10 |
| Neighborhood deprivation index | |||||
| Quartile 1 (least deprived) | 71 667 (23.8) | 39 020 (22.4) | 11 181 (23.6) | 21 466 (27.0) | 0.06 |
| Quartile 2 | 71 050 (23.6) | 42 383 (24.4) | 11 232 (23.7) | 17 435 (21.9) | |
| Quartile 3 | 70 793 (23.5) | 41 121 (23.6) | 10 915 (23.0) | 18 757 (23.6) | |
| Quartile 4 (most deprived) | 71 598 (23.8) | 41 351 (23.8) | 11 422 (24.1) | 18 825 (23.6) | |
| Missing | 15 885 (5.3) | 10 031 (5.8) | 2700 (5.7) | 3154 (4.0) | |
Abbreviation: RCL, recreational cannabis legalization.
Percentages may not add to 100 due to rounding.
A 1-month lag was used to reflect the timing of data collection because self-report asks about use since the start of pregnancy and toxicology tests reflect use up to 30 days prior. Thus, the period pre-RCL passage included pregnancies screened January 1, 2012, to November 30, 2016; the period post-RCL passage and pre-RCL implementation included pregnancies screened December 1, 2016, to January 31, 2018; and the period post-RCL implementation included pregnancies screened February 1, 2018, to December 31, 2019.
Standardized difference is the difference in means or proportions divided by standard error; imbalance is defined as an absolute value greater than 0.20 (small effect size).33
Race and ethnicity were self-reported by individuals. Other race includes Alaska Native, American Indian, Hawaiian Islander, and Pacific Islander. These categories were grouped together owing to small sample sizes.