Table 1 Participant sociodemographic characteristics and mean birth weight (grams) among MIREC study participants in Canada, 2008–2011
| Â | n (%)a | Birth weight (g) Mean (SD) |
|---|---|---|
Total | 1982 (100) | 3452 (532) |
Race and ethnicity | ||
 White | 1517 (82) | 3479 (529) |
 Others | 339 (18) | 3334 (529) |
Age | ||
 ≤ 24 | 117 (6) | 3404 (617) |
 25–29 | 443 (24) | 3483 (505) |
 30–34 | 655 (36) | 3452 (495) |
 35–39 | 502 (27) | 3444 (570) |
 40 +  | 127 (7) | 3428 (561) |
Education levels | ||
 High school diploma or less | 160 (9) | 3381 (571) |
 Some college, trade school, or college diploma | 538 (29) | 3444 (546) |
 Undergraduate degree | 681 (37) | 3486 (512) |
 Graduate degree | 475 (26) | 3435 (528) |
Household income | ||
 ≤ $20,000 | 72 (4) | 3348 (515) |
 $20,001—$40,000 | 152 (9) | 3445 (572) |
 $40,001—$60,000 | 187 (11) | 3458 (543) |
 $60,001—$80,000 | 286 (16) | 3457 (530) |
 $80,001—$100,000 | 358 (20) | 3440 (531) |
 > $100,000 | 715 (40) | 3475 (516) |
Smoking status | ||
 Never | 1137 (61) | 3442 (520) |
 Current | 105 (6) | 3366 (657) |
 Former | 498 (27) | 3496 (517) |
 Quit during Pregnancy | 115 (6) | 3432 (569) |
Parity | ||
 0 | 812 (44) | 3407 (546) |
 1 | 751 (40) | 3496 (508) |
 2 | 221 (12) | 3469 (559) |
 3 +  | 72 (4) | 3454 (502) |
Pre-pregnancy BMI | ||
 Underweight | 49 (3) | 3302 (503) |
 Normal | 1040 (61) | 3429 (496) |
 Overweight | 371 (22) | 3515 (521) |
 Obese | 258 (15) | 3466 (647) |
 Infant Sex | ||
 Male | 974 (53) | 3500 (534) |
 Female | 877 (47) | 3399 (524) |