Table 2 Characteristics of the studied population per BMI trajectory clusters. With continuous variables, mean (standard deviation, SD) and with categorical variables, n (%) reported.
Female BMI trajectory types | Male BMI trajectory types | |||||
|---|---|---|---|---|---|---|
Variable /levels | Type 1 | Type 2 | Type 3 | Type 1 | Type 2 | Type 3 |
Cohort | ||||||
NFBC1966 | 663 (42.3) | 597 (58.1) | 193 (47.7) | 678 (40.6) | 645 (66.3) | 288 (55.3) |
NFBC1986 | 903 (57.7) | 431 (41.9) | 212 (52.3) | 991 (59.4) | 328 (33.7) | 233 (44.7) |
Average number of height measurements | 22.8 (4.4) | 22.7 (4.8) | 22.7 (5.0) | 22.7 (4.3) | 22.5 (4.8) | 21.9 (4.5) |
Average number of weight measurements | 24.3 (4.9) | 24.0 (5.4) | 24.4 (5.8) | 24.2 (4.8) | 23.5 (5.1) | 23.2 (5.0) |
Maternal age at birth, years | 27.7 (5.8) | 27.5 (5.8) | 28.0 (6.3) | 28.0 (5.7) | 27.7 (5.9) | 27.9 (5.8) |
Maternal smoking during pregnancy | ||||||
No | 1210 (78.0) | 841 (82.7) | 300 (75.0) | 1303 (79.0) | 759 (79.6) | 397 (76.9) |
Yes, quitted | 79 (5.1) | 41 (4.0) | 21 (5.2) | 73 (4.4) | 62 (6.5) | 26 (5.0) |
Yes | 262 (16.9) | 135 (13.3) | 79 (19.8) | 274 (16.6) | 133 (13.9) | 93 (18.0) |
Maternal education | ||||||
High | 250 (17.0) | 149 (15.2) | 54 (14.0) | 232 (15.0) | 131 (14.0) | 60 (12.0) |
Medium | 411 (27.9) | 262 (26.8) | 96 (24.8) | 473 (30.5) | 230 (24.7) | 131 (27.5) |
Low | 811 (55.1) | 568 (58.0) | 237 (61.2) | 845 (54.5) | 572 (61.3) | 286 (60.0) |
Maternal pre-pregnancy BMI, kg/m2 | 22.7 (3.3) | 22.3 (2.9) | 23.2 (3.7) | 22.7 (3.4) | 22.4 (3.0) | 22.6 (3.0) |
Mode of delivery | ||||||
Non-instrumental vaginal delivery | 889 (77.3) | 526 (80.2) | 237 (82.0) | 970 (76.4) | 445 (78.3) | 274 (79.0) |
C-section | 170 (14.8) | 87 (13.3) | 37 (12.8) | 170 (13.4) | 68 (12.0) | 45 (13.0) |
Other (vacuum extraction, forceps) | 90 (7.9) | 43 (6.6) | 15 (5.2) | 130 (10.2) | 55 (9.7) | 28 (8.1) |
Multiple birth | ||||||
Singleton | 1535 (98.0) | 1016 (98.8) | 395 (97.5) | 1618 (96.9) | 956 (98.3) | 510 (97.9) |
Twin | 31 (2.0) | 12 (1.2) | 10 (2.5) | 50 (3.0) | 16 (1.6) | 11 (2.1) |
Triplet | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.1) | 1 (0.1) | 0 (0.0) |
Parity | ||||||
No | 542 (34.7) | 360 (35.2) | 151 (37.4) | 580 (34.8) | 353 (36.4) | 203 (39.2) |
Yes | 1022 (65.3) | 664 (64.8) | 253 (62.6) | 1087 (65.2) | 618 (63.6) | 315 (60.8) |
Gestational age, weeks | 39.9 (1.7) | 40.0 (1.7) | 40.0 (1.7) | 39.8 (1.8) | 40.0 (1.6) | 39.9 (1.8) |
Birth status | ||||||
Term ( ≥ 37 weeks) | 1474 (95.6) | 979 (96.5) | 384 (95.8) | 1544 (93.7) | 925 (97.2) | 493 (96.7) |
Preterm ( < 37 weeks) | 68 (4.4) | 36 (3.5) | 17 (4.2) | 104 (6.3) | 27 (2.8) | 17 (3.3) |
Birth weight, grams | 3455 (500) | 3457 (482) | 3522 (537) | 3573 (547) | 3562 (522) | 3594 (522) |
Place of residence at birth | ||||||
Town | 685 (43.8) | 445 (43.3) | 185 (45.9) | 684 (41.1) | 462 (47.5) | 209 (40.4) |
Village centre | 502 (32.1) | 331 (32.2) | 119 (29.5) | 588 (35.3) | 297 (30.6) | 184 (35.6) |
Remote village | 378 (24.2) | 251 (24.4) | 99 (24.6) | 392 (23.6) | 213 (21.9) | 124 (24.0) |
