Table 1.
Characteristics of INMA and ENVIRONAGE participants.
| Characteristics | INMA (n = 376) | ENVIRONAGE (n = 550) |
|---|---|---|
| Maternal | ||
| Age (years) | 32.2 ± 3.9* | 29.0 ± 4.6* |
| Smoking | ||
| Never | 170 (45.2)* | 354 (64.4)* |
| Quit smoking before week 12 | 143 (38.0)* | 119 (21.6)* |
| During entire pregnancy | 63 (16.8)* | 77 (14.0)* |
| Education | ||
| Primary school or none | 75 (20.0)* | 67 (12.2)* |
| Secondary school | 167 (44.4)* | 203 (36.9)* |
| University | 134 (35.6)* | 280 (50.9)* |
| Parity | ||
| 1 | 212 (56.4) | 299 (52.4) |
| 2 | 138 (36.7) | 195 (35.5) |
| ≥ 3 | 26 (6.9) | 56 (10.2) |
| Prepregnancy BMI (kg/m2) | 23.5 ± 4.4 | 24.1 ± 4.5 |
| Ethnicity | ||
| European | 343 (91.2) | 485 (88.2) |
| Non-European | 33 (8.8) | 65 (11.8) |
| Cohort | ||
| Valencia | 63 (16.8) | NA |
| Asturias | 37 (9.8) | NA |
| Sabadell | 120 (31.9) | NA |
| Gipuzkoa | 156 (41.5) | NA |
| ENVIRONAGE | NA | 550 (100.0) |
| Time spent at home | ||
| > 15 hr/day | 214 (56.9) | NA |
| ≤ 15 hr/day | 162 (43.1) | NA |
| Newborn | ||
| Gestational age (weeks) | 39.9 ± 1.3 | 39.3 ± 1.2 |
| Sex | ||
| Male | 194 (51.6) | 277 (50.4) |
| Female | 182 (48.4) | 273 (49.4) |
| Season at birth | ||
| January–March | 99 (26.3) | 156 (28.4) |
| April–June | 102 (27.1) | 131 (23.8) |
| July–September | 92 (24.5) | 143 (26.0) |
| October–December | 83 (22.1) | 120 (21.8) |
| Preterm delivery (< 37 weeks) | ||
| Yes | 7 (1.9) | 14 (2.6) |
| No | 369 (98.1) | 536 (97.5) |
| Vaginal delivery | ||
| No | 322 (85.6) | 521 (94.7) |
| Yes | 54 (14.4) | 29 (5.3) |
| Birth weight (g) | 3,290 ± 423* | 3,429.6 ± 432* |
| Placental mtDNA content | 1.3 (1.1–1.5)* | 1.0 (0.7–1.4)* |
| NA, not applicable. Continuous covariates expressed by mean ± SD or geometric mean and 25–75th percentile; categorical covariates are described by frequencies (%). Differences between cohorts were assessed using independent t-tests. Subjects without available information have been excluded before performing the independent t-tests.*p < 0.05. | ||