Table 1.
Characteristics of 558 postdelivery women and 365 currently pregnant women
| Characteristics | N (%) or mean (SD) | |||
| Postdelivery women | Currently pregnant women | |||
| Never HTP smokers | Ever HTP smokers | Never HTP smokers | Ever HTP smokers | |
| Overall | n=493 | n=65 | n=319 | n=46 |
| Maternal and neonatal risk | ||||
| Hypertensive disorders of pregnancy | 32 (6.5) | 9 (13.8)* | NA | NA |
| Low birth weight <2500 g | 44 (8.9) | 12 (18.5)* | NA | NA |
| Preterm birth <37 weeks | 19 (3.9) | 4 (6.2) | NA | NA |
| Imminent preterm birth | 82 (16.6) | 18 (27.7)* | NA | NA |
| Age | 32.4 (4.1) | 30.9 (4.2)** | 31.9 (4.3) | 31.3 (4.7) |
| Ever combustible cigarette smoking | 82 (16.6) | 55 (84.6)*** | 54 (16.9) | 41 (89.1)*** |
| Educational attainment ≥13 years | 410 (83.2) | 37 (56.9)*** | 278 (87.1) | 31 (67.4)** |
| Managerial workers | 19 (3.9) | 5 (7.7) | 16 (5.0) | 2 (4.3) |
| Comorbidity of hypertension or diabetes | 35 (7.1) | 4 (6.2) | 4 (1.3) | 4 (8.7)** |
| Household income | n=436 | n=58 | n=263 | n=41 |
| <¥200 million | 13 (3.0) | 3 (5.2) | 6 (2.3) | 1 (2.4) |
| ¥200 to <¥600 million | 200 (45.9) | 30 (51.7) | 115 (43.7) | 19 (46.3) |
| ≥¥600 million | 223 (51.1) | 25 (43.1) | 142 (54.0) | 21 (51.2) |
| Never combustible cigarette smokers | n=411 | n=10 | n=265 | n=5 |
| Maternal and neonatal risk | ||||
| Hypertensive disorders of pregnancy | 26 (6.3) | 1 (10.0) | NA | NA |
| Low birth weight <2500 g | 34 (8.3) | 3 (30.0)* | NA | NA |
| Preterm birth <37 weeks | 17 (4.1) | 0 (0) | NA | NA |
| Imminent preterm birth | 69 (16.8) | 3 (30.0) | NA | NA |
| Age | 32.2 (4.0) | 33.3 (2.3) | 31.7 (4.3) | 30.2 (1.8) |
| Educational attainment ≥13 years | 348 (84.7) | 7 (70) | 235 (88.7) | 4 (80.0) |
| Managerial workers | 16 (3.9) | 1 (10) | 14 (5.3) | 0 (0) |
| Comorbidity of hypertension or diabetes | 24 (5.8) | 0 (0) | 4 (1.5) | 0 (0) |
| Household income | n=361 | n=9 | n=219 | n=5 |
| <¥200 million | 10 (2.8) | 0 (0) | 5 (2.3) | 0 (0) |
| ¥200 to <¥600 million | 160 (44.3) | 4 (44.4) | 97 (44.3) | 3 (60.0) |
| ≥¥600 million | 191 (52.9) | 5 (55.6) | 117 (53.4) | 2 (40.0) |
| Ever combustible cigarette smokers | n=82 | n=55 | n=54 | n=41 |
| Maternal and neonatal risk | ||||
| Hypertensive disorders of pregnancy | 6 (7.3) | 8 (14.5) | NA | NA |
| Low birth weight <2500 g | 10 (12.2) | 9 (16.4) | NA | NA |
| Preterm birth <37 weeks | 2 (2.4) | 4 (7.3) | NA | NA |
| Imminent preterm birth | 13 (15.9) | 15 (27.3) | NA | NA |
| Age | 33.5 (4.3) | 30.5 (4.3)*** | 32.9 (4.2) | 31.4 (5.0) |
| Educational attainment ≥13 years | 62 (75.6) | 30 (54.5)** | 43 (79.6) | 27 (65.9) |
| Managerial workers | 3 (3.7) | 4 (7.3) | 2 (3.7) | 2 (4.9) |
| Comorbidity of hypertension or diabetes | 11 (13.4) | 4 (7.3) | 0 (0) | 4 (9.8)* |
| Household income | n=75 | n=49 | n=44 | n=36 |
| <¥200 million | 3 (4.0) | 3 (6.1) | 1 (2.3) | 1 (2.8) |
| ¥200 to <¥600 million | 40 (53.3) | 26 (53.1) | 18 (40.9) | 16 (44.4) |
| ≥¥600 million | 32 (42.7) | 20 (40.8) | 25 (56.8) | 19 (52.8) |
*P<0.05, **p<0.01, ***p<0.001 for χ2 test or t-test.
HTP, heated tobacco product; NA, not applicable.