TABLE 1.
Study Participant Characteristics, MIREC Study, Canada, 2008–2011 (n = 1253)∗
| Characteristic | n (%) |
| Maternal age, yrs | |
| ≤29 | 328 (26.2) |
| 30–34 | 451 (36.0) |
| ≥35 | 474 (37.8) |
| Household income ($CAD) | |
| ≤30,000 | 90 (7.5) |
| 30,001–50,000 | 117 (9.7) |
| 50,001–100,000 | 513 (42.6) |
| >100,000 | 485 (40.3) |
| Smoking | |
| Never or quit before pregnancy | 1102 (88.0) |
| Quit when pregnancy confirmed | 90 (7.2) |
| Current | 61 (4.9) |
| Pre-pregnancy BMI† | |
| Underweight (<18.5) | 26 (2.2) |
| Normal (18.5–24.9) | 708 (60.5) |
| Overweight (25–29.9) | 268 (22.9) |
| Obese (≥30) | 168 (14.4) |
| Maternal allergy‡ | |
| No | 1199 (95.7) |
| Yes | 54 (4.3) |
| Parity | |
| Nulliparous | 524 (41.9) |
| Primiparous | 511 (40.9) |
| Multiparous | 216 (17.3) |
| Infant sex | |
| Male | 671 (62.2) |
| Female | 582 (46.5) |
| Birth weight, g | |
| ≤2500 | 11 (0.9) |
| 2501–4000 | 1050 (83.8) |
| >4000 | 192 (15.3) |
*Subgroup total may not equal 1253 due to missing data.
†World Health Organization Classification (WHO, 2006).
‡Defined as use of maternal allergy medication.