Table 1. Pregnancy Characteristics Overall and by Prenatal Cannabis Use.
| Pregnancy characteristics | No. (%) | Standardized differencea | ||
|---|---|---|---|---|
| Overall (N = 316 722) | Prenatal cannabis use | |||
| Yes (n = 20 053 [6.3%]) | No (n = 296 669 [93.7%]) | |||
| Age at pregnancy onset, y | ||||
| <18 | 2994 (0.9) | 617 (3.1) | 2377 (0.8) | 0.68 |
| 18-24 | 46 021 (14.5) | 7541 (37.6) | 38 480 (13.0) | |
| 25-30 | 87 882 (27.7) | 5469 (27.3) | 82 413 (27.8) | |
| 31-35 | 113 020 (35.7) | 4250 (21.2) | 108 770 (36.7) | |
| ≥36 | 66 805 (21.1) | 2176 (10.9) | 64 629 (21.8) | |
| Self-reported race and ethnicity | ||||
| Hispanic | 83 145 (26.3) | 5583 (27.8) | 77 562 (26.1) | 0.80 |
| Non-Hispanic | ||||
| American Indian/Alaska Nativeb | 1078 (0.3) | 144 (0.1) | 934 (0.3) | |
| Asian/Pacific Islander | 84 039 (26.5) | 1191 (5.9) | 82 848 (27.9) | |
| Black | 20 053 (6.3) | 4480 (22.3) | 15 573 (5.2) | |
| White | 118 333 (37.4) | 7750 (38.6) | 110 583 (37.3) | |
| Multiracialb | 4540 (1.3) | 622 (0.2) | 3918 (1.2) | |
| Unknownb | 5534 (1.8) | 283 (0.1) | 5251 (1.7) | |
| Parity | ||||
| 0 | 129 585 (40.9) | 9906 (49.4) | 119 679 (40.3) | 0.25 |
| 1 | 110 434 (34.9) | 5471 (27.3) | 104 963 (35.4) | |
| ≥2 | 65 908 (20.8) | 3408 (17.0) | 62 500 (21.1) | |
| Unknown | 10 795 (3.4) | 1268 (6.3) | 9527 (3.2) | |
| Prenatal care initiation | ||||
| Adequate plus (months 1-2) | 198 083 (62.5) | 11 932 (59.5) | 186 151 (62.7) | 0.13 |
| Adequate (months 3-5) | 99 481 (31.4) | 6619 (33.0) | 92 862 (31.3) | |
| Intermediate (months 5-6) | 11 297 (3.6) | 962 (4.8) | 10 335 (3.5) | |
| Inadequate (months 7+) | 7861 (2.5) | 540 (2.7) | 7321 (2.5) | |
| Insured by Medicaid | 28 803 (9.1) | 5049 (25.2) | 23 754 (8.0) | 0.47 |
| Neighborhood deprivation index, quartile | ||||
| 1 (Least deprivation) | 74 902 (23.6) | 2641 (13.2) | 72 261 (24.4) | 0.41 |
| 2 | 74 934 (23.7) | 3987 (19.9) | 70 947 (23.9) | |
| 3 | 74 907 (23.7) | 5315 (26.5) | 69 592 (23.5) | |
| 4 (Most deprivation) | 74 916 (23.7) | 7510 (37.5) | 67 406 (22.7) | |
| Unknown | 17 063 (5.4) | 600 (3.0) | 16 463 (5.5) | |
| Noncannabis substance use during pregnancy | ||||
| Alcohol | 29 565 (9.3) | 3987 (19.9) | 25 578 (8.6) | 0.33 |
| Nicotine | 14 281 (4.5) | 4499 (22.4) | 9782 (3.3) | 0.60 |
| Opioids | 22 054 (7.0) | 2561 (12.8) | 19 493 (6.6) | 0.21 |
| Stimulants | 1712 (0.5) | 598 (3.0) | 1114 (0.4) | 0.20 |
| Anxiety or sleep medications | 9163 (2.9) | 1370 (6.8) | 7793 (2.6) | 0.20 |
| Prepregnancy BMI categories | ||||
| Underweight (<18.5) | 7164 (2.3) | 537 (2.7) | 6627 (2.2) | 0.24 |
| Normal (18.5-24.9) | 137 375 (43.4) | 6945 (34.6) | 130 430 (44.0) | |
| Overweight (25-29.9) | 83 426 (26.3) | 5275 (26.3) | 78 151 (26.3) | |
| Obesity (≥30) | 73 367 (23.2) | 6433 (32.1) | 66 934 (22.6) | |
| Unknown | 15 390 (4.9) | 863 (4.3) | 14 527 (4.9) | |
| Diagnoses and medications | ||||
| 2 y Before pregnancy | ||||
| Diabetes | 4026 (1.3) | 222 (1.1) | 3804 (1.3) | −0.02 |
| 1 y Before pregnancy through first prenatal visit | ||||
| Mood/anxiety disorder | 34 984 (11.0) | 4514 (22.5) | 30 470 (10.3) | 0.34 |
| Other psychiatric disorder | 7498 (2.4) | 1269 (6.3) | 6229 (2.1) | 0.21 |
| Substance use disorder diagnosis (other than cannabis) | 11 220 (3.5) | 3251 (16.2) | 7969 (2.7) | 0.48 |
| Pregnancy onset through first prenatal visit | ||||
| Nausea and vomiting | 35 639 (11.3) | 4642 (23.1) | 30 997 (10.4) | 0.34 |
| Antidepressant medication use | 6441 (2.0) | 865 (4.3) | 5576 (1.9) | 0.14 |
| Frequency of cannabis use | ||||
| Daily | 1930 (0.6) | 1930 (9.6) | 0 | 1.31 |
| Weekly | 2345 (0.7) | 2345 (11.7) | 0 | |
| Monthly or less | 4892 (1.5) | 4892 (24.4) | 0 | |
| Never | 296 669 (93.7) | 0 | 296 669 (100) | |
| Unknown frequency, positive toxicology results | 10 886 (3.4) | 10 886 (54.3) | 0 | |
| Fetal outcome | ||||
| Live birth | 314 480 (99.3) | 19 880 (99.1) | 294 600 (99.3) | 0.20 |
| Stillbirth | 1510 (0.5) | 114 (0.6) | 1396 (0.5) | |
| Therapeutic abortion | 732 (0.2) | 59 (0.3) | 673 (0.2) | |
Abbreviation: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared).
a
Standardized difference is the difference in proportions divided by the standard error; imbalance defined as absolute value greater than 0.20 (small effect size).
b
These categories were collapsed in the models.