Table 1.
Characteristics of study participants, MIREC study, 2008–2011 (N = 1723) a.
| Characteristic | 25% | Median | 75% | Range | |
|---|---|---|---|---|---|
| Maternal age (y) | 29.0 | 33.0 | 37.0 | 18.0–49.0 | |
| Gestational age (wks) | 38.0 | 39.0 | 40.0 | 34.0–42.0 | |
| Birthweight (g) | 3170 | 3473.0 | 3785 | 1630–5620 | |
| Gestational weight gain (kg) | 11.7 | 15.2 | 18.7 | −3.8–44.5 | |
| N | % | ||||
| Pre-pregnancy BMI, kg/m2 b | |||||
| Underweight (<18.5) | 44 | 2.7 | |||
| Normal (18.5 to 24.9) | 993 | 61.6 | |||
| Overweight (25 to 29.9) | 348 | 21.6 | |||
| Obese (≥30) | 228 | 14.1 | |||
| Gestational weight gain c | |||||
| Below Recommendations | 278 | 17.8 | |||
| Within Recommendations | 403 | 25.8 | |||
| Above Recommendations | 883 | 56.5 | |||
| Household income ($CAD) | |||||
| ≤30,000 | 128 | 7.7 | |||
| 30,001–50,000 | 158 | 9.6 | |||
| 50,001–100,000 | 683 | 41.4 | |||
| >100,000 | 679 | 41.2 | |||
| Mode of delivery | |||||
| Vaginal | 1246 | 72.3 | |||
| Caesarean | 477 | 27.7 | |||
| Maternal smoking | |||||
| Never or quit before pregnancy | 1517 | 88.0 | |||
| Quit during pregnancy | 119 | 6.9 | |||
| Current | 87 | 5.1 | |||
| Parity | |||||
| 0 | 742 | 43.1 | |||
| 1 | 696 | 40.4 | |||
| ≥2 | 283 | 16.4 | |||
| Infant sex | |||||
| Male | 902 | 52.4 | |||
| Female | 821 | 47.7 | |||
Abbreviations: MIREC, Maternal-Infant Research on Environmental Chemicals; IQR, interquartile range; PFOA, perfluorooctanoate; PFOS, perfluorooctanesulfonate; PFHxS, perfluorohexanesulfanoate; a subtotals may not equal sample size due to missing covariate data; b According to the World Health Organization; c According to the U.S. IOM guidelines [15].