Table 2.
Characteristics of the cohorts [mean (SD) or n (%)]
| INUENDO |
INMA |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Greenland (n = 518) | Ukraine (n = 490) | FLEHSI (n = 256) | PELAGIE (n = 188) | PCB cohort (n = 455) | Menorca (n = 304) | Valencia (n = 347) | Sabadell (n = 442) | Gipuzkoa (n = 310) | HUMIS (n = 1015) | DUISBURG (n = 112) | |
| Low birth weight (<2500 g) | 22 (4.2) | 12 (2.5) | 6 (2.3) | 3 (1.6) | 18 (3.9) | 11 (3.6) | 22 (6.3) | 18 (4.1) | 11 (3.6) | 75 (7.4) | 6 (5.4) |
| Gestational age (weeks) | 39.6 (1.7) | 39.1 (1.2) | 39.2 (1.3) | 39.5 (1.2) | 39.7 (1.0) | 39.3 (1.5) | 39.5 (1.9) | 39.7 (1.3) | 39.8 (1.4) | 39.6 (2.5) | 39.7 (1.25) |
| Missings (%) | 0 | 2 (0.4) | 0 | 0 | 5 (1) | 0 | 0 | 0 | 0 | 3 (0.3) | 0 |
| Determination of GA | |||||||||||
| 1st day last menstruation | 518 (100) | 490 (100) | – | – | – | – | 347 | 442 | 310 | – | 112 (100) |
| Ultrasound | – | – | – | – | 456 (100) | – | – | – | – | – | – |
| Combination 1&2 | – | – | – | – | – | – | – | – | – | – | – |
| Other | – | – | 256 (100) | 188 (100) | – | 304 (100) | – | – | – | 1015 | – |
| Missings (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Term | |||||||||||
| Preterm (<37 weeks) | 23 (4.4) | 9 (1.8) | 12 (4.7) | 2 (1.1) | 5 (1.1) | 13 (4.3) | 23 (6.6) | 13 (2.9) | 11 (3.6) | 114 (11.2) | 5 (4.5) |
| Term (37–42 weeks) | 487 (94.0) | 479 (97.8) | 244 (95.3) | 186 (98.9) | 446 (97.8) | 291 (95.7) | 317 (91.4) | 426 (96.4) | 293 (94.5) | 806 (79.4) | 107 (95.5) |
| Over term (>42 weeks) | 8 (1.6) | – | – | – | – | – | 7 (2.0) | 3 (0.7) | 6 (1.9) | 92 (9.1) | – |
| Missings (%) | 0 | 2 (0.4) | 0 | 0 | 5 (1.1) | 0 | 0 | 0 | 0 | 3 (0.3) | 0 |
| Child’s sex | |||||||||||
| Boy | 277 (53.5) | 259 (52.9) | 122 (47.7) | 89 (47.3) | 226 (49.6) | 146 (48.7) | 180 (51.9) | 227 (51.4) | 155 (50.0) | 555 (54.7) | 63 (56.3) |
| Girl | 241 (46.5) | 229 (46.7) | 134 (52.3) | 99 (52.7) | 229 (50.2) | 156 (51.3) | 167 (48.1) | 215 (48.6) | 155 (50.0) | 458 (45.1) | 49 (43.7) |
| Missings (%) | 0 | 2 (0.4) | 0 | 0 | 1 (0.2) | 0 | 0 | 0 | 0 | 2 (0.2) | 0 |
| Maternal age at delivery | |||||||||||
| <25 years | 119 (23.0) | 258 (52.6) | 17 (6.6) | 13 (6.9) | 189 (41.5) | 37 (12.2) | 11 (3.2) | 18 (4.1) | 4 (1.3) | 155 (15.3) | 4 (3.6) |
| 25–29 years | 56 (10.8) | 135 (27.6) | 113 (44.1) | 72 (38.3) | 159 (34.9) | 120 (39.5) | 93 (26.8) | 128 (29.0) | 51 (16.5) | 350 (34.5) | 20 (17.9) |
| 30–34 years | 40 (7.7) | 55 (11.2) | 101 (39.5) | 74 (39.4) | 72 (15.8) | 107 (35.2) | 172 (49.6) | 191 (43.2) | 171 (55.2) | 343 (33.8) | 51 (45.5) |
| ≥35 years | 43 (8.3) | 18 (3.7) | 24 (9.4) | 29 (15.4) | 26 (5.7) | 40 (13.1) | 68 (19.6) | 104 (23.5) | 84 (27.1) | 167 (16.4) | 37 (33.0) |
| Missings (%) | 260 (50.2) | 24 (4.9) | 1 (0.4) | 0 | 9 (2.0) | 0 | 3 (0.86) | 1 (0.2) | 0 | 0 | 0 |
| Maternal pre-pregnancy BMI | |||||||||||
| <18.5 kg/m2 | 16 (3.1) | 72 (14.7) | 12 (4.7) | 10 (5.3) | 67 (14.7) | 0 | 11 (3.2) | 25 (5.7) | 10 (3.2) | 39 (3.8) | 0 |
| 18.5–24.9 kg/m2 | 316 (61.0) | 347 (70.8) | 183 (71.5) | 143 (76.1) | 264 (57.9) | 145 (47.7) | 234 (67.4) | 292 (66.1) | 242 (78.1) | 609 (60.0) | 47 (42.0) |
| 25–29.9 kg/m2 | 129 (24.9) | 52 (10.6) | 39 (15.2) | 26 (13.8) | 65 (14.3) | 119 (39.1) | 67 (19.3) | 84 (19.0) | 44 (14.2) | 234 (23.1) | 49 (43.8) |
| ≥30 kg/m2 | 53 (10.2) | 11 (2.2) | 16 (6.3) | 8 (4.3) | 20 (4.4) | 28 (9.2) | 35 (10.1) | 41 (9.3) | 14 (4.5) | 105 (10.3) | 16 (14.2) |
| Missings (%) | 4 (0.8) | 8 (1.6) | 6 (2.3) | 1 (0.5) | 39 (8.6) | 12 (3.95) | 0 | 0 | 0 | 28 (2.8) | 0 |
| Maternal height (cm) | 162 (6) | 165 (5) | 166 (6) | 164 (5) | 164 (6) | 160 (5.8) | 162 (6.3) | 162 (5.9) | 163 (5.9) | 167 (6.3) | 168 (6) |
| Missings (%) | 3 (0.6) | 5 (1.0) | 3 (1.2) | 1 (0.5) | 15 (3.2) | 12 (4.0) | 0 | 0 | 0 | 15 (1.5) | 0 |
| Parity | |||||||||||
| 0 | 165 (31.8) | 392 (80.0) | 145 (56.6) | 79 (42.0) | 178 (39.0) | 127 (41.8) | 198 (57.1) | 253 (57.2) | 166 (53.6) | 421 (41.5) | 60 (53.6) |
| ≥1 | 353 (68.2) | 98 (20.0) | 111 (43.4) | 109 (58.0) | 277 (60.8) | 177 (58.2) | 149 (42.9) | 187 (42.3) | 144 (46.4) | 593 (58.4) | 52 (46.4) |
| Missings (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 (0.5) | 0 | 1 (0.1) | 0 |
| Maternal education | |||||||||||
| Low | 260 (50.2) | 262 (53.5) | 13 (5.1) | 28 (14.9) | 207 (45.4) | 175 (57.6) | 91 (26.2) | 105 (23.8) | 34 (11.0) | 86 (8.5) | 13 (11.6) |
| Medium | 191 (36.9) | 168 (34.3) | 188 (73.4) | 33 (17.6) | 219 (48.0) | 73 (24.0) | 152 (43.8) | 189 (42.8) | 115 (37.1) | 136 (13.4) | 39 (34.8) |
| High | 7 (1.3) | 0 | 53 (20.7) | 126 (67.0) | 27 (5.9) | 45 (14.8) | 104 (30.0) | 145 (32.8) | 160 (51.6) | 779 (76.8) | 60 (53.6) |
| Missings (%) | 60 (11.6) | 60 (12.2) | 2 (0.8) | 1 (0.5) | 2 (0.4) | 11 (3.6) | 0 | 3 (0.7) | 1 (0.3) | 14 (1.4) | 0 |
| Duration of total breastfeeding (exclusive and partial) (months) | 9.27 (9.3) | 7.7 (3.9) | 4.44 (5.6) | 3.1 (3.8) | 8.7 (8.8) | 4.81 (4.2) | 5.31 (4.3) | 6.40 (4.6) | 6.71 (4.6) | 12.2 (5.3) | 9.2 (5.3) |
| Missings (%) | 69 (13.3) | 44 (8.9) | 14 (5.1) | 2 (1.1) | 5 (1.1) | 0 | 0 | 1 (0.2) | 13 (4.2) | 7 (0.7) | 13 (11.0) |
| Duration of exclusive breastfeeding (months) | 4.02 (1.6) | 4.51 (1.7) | 2.13 (2.1) | – | 3.07 (1.8) | 2.40 (2.1) | 2.83 (2.2) | 2.32 (2.0) | 3.0 (2.2) | 4.6 (2.0) | 5.12 (2.4) |
| Missings (%) | 146 (28.2) | 46 (9.4) | 7 (2.5) | – | 3 (0.7) | 0 | 0 | 4 (0.9) | 23 (7.4) | 7 (0.7) | 14 (11.8) |
| Maternal smoking during pregnancy | |||||||||||
| Non-smoking | 54 (10.4) | 248 (50.6) | 234 (91.4) | 166 (88.3) | 368 (80.7) | 197 (64.8) | 213 (61.4) | 317 (71.7) | 238 (76.8) | 750 (73.9) | 94 (83.9) |
| Yes | 376 (72.6) | 112 (22.9) | 21 (8.2) | 20 (10.6) | 71 (15.6) | 107 (35.2) | 134 (38.6) | 119 (26.9) | 62 (20.0) | 67 (6.6) | 18 (16.1) |
| Missings (%) | 88 (17.0) | 130 (26.5) | 1 (0.4) | 2 (1.1) | 16 (3.5) | 0 | 0 | 6 (1.4) | 10 (3.2) | 198 (19.5) | 0 |
| Type of sample | |||||||||||
| Blood mother | 518 (100) | 490 (100) | – | – | – | – | 347 | 442 | 310 | – | 112 (100) |
| Cord blood | – | – | 256 (100) | 188 (100) | 455 (100) | 304 (100) | – | – | – | – | – |
| Milk | – | – | – | – | – | – | – | – | – | 1015 | – |
| Missings (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
BMI, body mass index; GA, gestational age.