Table 2. Frequency and Risk Ratios of Maternal Outcomes by Any Prenatal Cannabis Use.
| Maternal outcomes | Pregnancies, No. (%) | Risk ratios of maternal outcomes for any prenatal cannabis use vs none (95% CI)a | |||
|---|---|---|---|---|---|
| Overall (N = 316 722) | Prenatal cannabis use | Model 1 | Model 2 | ||
| Yes (n = 20 053) | No (n = 296 669) | ||||
| Metabolic outcomes | |||||
| Hypertensive disordersb | |||||
| Gestational hypertension | 44 363 (14.7) | 3822 (20.3) | 40 541 (14.3) | 1.42 (1.38-1.46) | 1.17 (1.13-1.21) |
| Preeclampsia | 14 378 (4.8) | 1212 (6.4) | 13 166 (4.6) | 1.39 (1.31-1.47) | 1.08 (1.01-1.15) |
| Eclampsia | 384 (0.1) | 34 (0.2) | 350 (0.1) | 1.46 (1.03-2.08) | 1.17 (0.80-1.71) |
| Gestational diabetesc | 36 374 (11.7) | 1521 (7.7) | 34 853 (11.9) | 0.64 (0.61-0.68) | 0.89 (0.85-0.94) |
| Gestational weight gaind | |||||
| Within guidelines | 75 844 (25.2) | 3284 (17.1) | 72 560 (25.8) | NA | NA |
| Less than guidelines | 48 117 (16.0) | 2727 (14.2) | 45 390 (16.1) | 1.18 (1.15-1.21) | 1.05 (1.01-1.08) |
| Greater than guidelines | 176 898 (58.8) | 13 145 (68.6) | 176 898 (58.8) | 1.15 (1.15-1.16) | 1.09 (1.08-1.10) |
| Placental outcomes | |||||
| Placenta previa | 3499 (1.1) | 169 (0.8) | 3330 (1.1) | 0.75 (0.64-0.88) | 1.02 (0.87-1.20) |
| Placental abruption | 4002 (1.3) | 281 (1.4) | 3721 (1.3) | 1.12 (0.99-1.26) | 1.19 (1.05-1.36) |
| Placenta accretae | 499 (0.2) | 37 (0.2) | 462 (0.2) | 1.20 (0.86-1.67) | 1.34 (0.92-1.95) |
| Severe maternal morbidity | 10 338 (3.3) | 718 (3.6) | 9620 (3.2) | 1.10 (1.02-1.19) | 0.97 (0.89-1.05) |
Abbreviation: NA, not applicable.
Model 1: modified Poisson model with robust standard errors (no covariates). Model 2: adjusted for maternal sociodemographic characteristics (age category, race and ethnicity, neighborhood deprivation index), parity, birth year, prenatal care initiation, prepregnancy body mass index category, noncannabis prenatal substance use (alcohol, nicotine, opioids, stimulants, and anxiety/sleep medications), and maternal medical and mental health comorbidities (pregestational diabetes, nausea/vomiting during pregnancy, mood/anxiety disorders, other psychiatric disorders, substance use disorders [other than cannabis], and antidepressant use).
Pregnancies of individuals with chronic hypertension were excluded (n = 14 187).
Pregnancies of individuals with pregestational diabetes were excluded. In addition, gestational diabetes could not be ascertained for pregnancies ending in therapeutic abortion. A total of 4737 pregnancies were excluded. In model 2, pregestational diabetes was not included as a covariate for the gestational diabetes outcome.
Categories determined by the 2009 Institute of Medicine guidelines. Pregnancies with missing weight values were excluded (n = 15 863). Less than guidelines models were fit among pregnancies less than or within guidelines; greater than guidelines models were fit among pregnancies greater than or within guidelines.
Placenta accreta could only be ascertained for pregnancies that were delivered in a Kaiser Permanente Northern California facility and ended in live birth or stillbirth (alive at admission); 10 979 were excluded.