Table 1.
Characteristics of study participantsa
| Total group (n = 821) | Boys (n = 412) | Girls (n = 409) | P-value | |
|---|---|---|---|---|
| Maternal characteristics | ||||
| Age (years), mean (SD) | 32.0 (3.9) | 31.8 (3.9) | 32.1 (3.8) | 0.346 |
| Highest completed education, n (%) | ||||
| Primary school | 10 (1.2) | 3 (0.7) | 7 (1.7) | 0.428 |
| Secondary school | 265 (32.3) | 135 (32.8) | 130 (31.8) | |
| Higher education | 546 (66.5) | 274 (66.5) | 272 (66.5) | |
| Parity, n (%) primiparae | 522 (63.6) | 262 (63.6) | 260 (63.6) | 0.995 |
| Pre-pregnancy body mass index (kg/m2), mean (SD) | 23.5 (4.0) | 23.4 (4.0) | 23.7 (4.0) | 0.208 |
| Smoking habits during pregnancy, n (%) yes | 175 (21.3) | 87 (21.1) | 88 (21.5) | 0.776 |
| Child’s characteristics | ||||
| Sex, % | 412 (50.2) | 409 (49.8) | ||
| Birthweight (g), mean (SD) | 3533 (522) | 3588 (503) | 3477 (536) | 0.002 |
| Gestational age at birth (weeks), median (95% range) | 40.3 (36.3-42.4) | 40.3 (36.5-42.4) | 40.3 (36.0-42.4) | 0.710 |
| Breast feeding duration (months), mean (SD) | 4.8 (3.8) | 4.7 (3.7) | 4.9 (3.9) | 0.442 |
| Introduction of solid foods, n (%) | ||||
| <3 months | 47 (5.7) | 23 (5.6) | 24 (5.9) | 0.885 |
| 3 to 6 months | 631 (76.9) | 316 (76.7) | 315 (77.0) | |
| >6 months | 143 (17.4) | 73 (17.7) | 70 (17.1) | |
| TV watching time, n (%) ≥ 2 hours/day | 76 (9.3) | 45 (10.9) | 31 (7.6) | 0.131 |
a
Values are expressed as means (SD), medians (95% range) or numbers of subjects (%). The values represent the pooled results after multiple imputation. Observed data are given in Supplemental Table S1. SD, standard deviation.