TABLE 2.
Baseline and pregnancy characteristics of women with liveborn singletons and no births in the 7-y follow-up period, by prepregnancy BMI (in kg/m2)
| BMI | ||||||
| Variable | All(n = 23,701) | <18.5(n = 1035) | 18.5–24.9(n = 16,247) | 25–29.9(n = 4641) | ≥30(n = 1778) | Missing |
| Age at conception (y) | 31.8 ± 4.11 | 31.2 ± 4.3 | 32.0 ± 4.1 | 31.5 ± 4.1 | 31.1 ± 4.0 | 0 |
| Parity [n (%)] | 0 | |||||
| Primiparous | 4149 (18) | 209 (20) | 2819 (17) | 770 (17) | 351 (20) | — |
| Multiparous | 19,552 (82) | 826 (80) | 13,428 (83) | 3871 (83) | 1427 (80) | — |
| Gestational age (d) | 279.7 ± 11.6 | 277.7 ± 13.0 | 279.7 ± 11.5 | 280.2 ± 11.3 | 279.6 ± 12.8 | 0 |
| Birth weight of child (g) | 3640 ± 571 | 3386 ± 564 | 3621 ± 546 | 3731 ± 558 | 3760 ± 623 | 85 |
| Socio-occupational status [n (%)] | 76 | |||||
| High | 12,383 (53) | 493 (48) | 9114 (56) | 2136 (46) | 640 (36) | — |
| Middle | 9057 (38) | 420 (41) | 5784 (36) | 1987 (43) | 866 (49) | — |
| Low | 2185 (9) | 118 (11) | 1305 (8) | 497 (11) | 265 (15) | — |
| Smoking during pregnancy [n (%)] | 4327 | |||||
| Nonsmoking | 14,558 (75) | 556 (66) | 9985 (75) | 2856 (75) | 1161 (77) | — |
| Smoking cessation | 1991 (10) | 94 (11) | 1387 (11) | 388 (10) | 122 (8) | — |
| Smoking | 2825 (15) | 187 (22) | 1867 (14) | 551 (15) | 220 (15) | — |
| Smoking after pregnancy [n (%)] | 4327 | |||||
| Continued nonsmoking | 14,419 (74) | 550 (66) | 9894 (75) | 2828 (75) | 1147 (76) | — |
| Smoking cessation or maintained cessation | 1383 (7) | 63 (7) | 961 (7) | 276 (7) | 83 (6) | — |
| Initiated smoking | 819 (4) | 43 (5) | 564 (4) | 151 (4) | 61 (4) | — |
| Continued smoking | 2753 (14) | 181 (22) | 1820 (14) | 540 (14) | 212 (14) | — |
| Leisure-time physical activity during pregnancy [n (%)] | 18 | |||||
| No exercise | 15,875 (67) | 723 (70) | 10,752 (66) | 3156 (68) | 1244 (70) | — |
| 1–180 min/wk | 6303 (27) | 244 (24) | 4390 (27) | 1221 (26) | 448 (25) | — |
| >180 min/wk | 1505 (6) | 67 (6) | 1091 (7) | 262 (6) | 85 (5) | — |
| Dietary pattern during pregnancy [n (%)] | 5214 | |||||
| Western | 3424 (19) | 200 (25) | 2245 (18) | 673 (19) | 306 (22) | — |
| Intermediate | 12,423 (67) | 497 (62) | 8481 (67) | 2508 (69) | 937 (68) | — |
| Health conscious | 2640 (14) | 101 (13) | 1946 (15) | 457 (13) | 136 (10) | — |
1
Mean ± SD (all such values).