Table 1.
Anthropometric and sociodemographic characteristics of women enrolled in the Alberta Pregnancy Outcomes and Nutrition Study (APrON) by pre-pregnancy BMI categories
| Characteristic | n* | Underweight | Normal | Overweight | Obese | P value |
| Pre-pregnancy weight (kg)† | 1820 | 49.17±5.09‡ | 59.72±6.48§ | 74.51 ± 6.77¶ | 93.78±13.46** | <0.001 |
| Height (cm)† | 1820 | 167.03±7.32 | 165.40±6.36 | 165.81±6.05 | 165.01±7.41 | 0.10 |
| Pre-pregnancy BMI (kg/m2)† | 1820 | 17.59±0.92‡ | 21.80±1.66§ | 27.06 ± 1.42¶ | 34.39±4.17** | <0.001 |
| Pre-pregnancy BMI (kg/m2) (%) | 1820 | 3.8 | 64.1 | 21.5 | 10.6 | |
| Body weight (kg)† | ||||||
| Trimester 1 | 486 | 51.20±4.31‡ | 61.79±7.31§ | 76.10 ± 7.37¶ | 94.58±13.27** | <0.001 |
| Trimester 2 | 1718 | 57.56±12.58‡ | 64.68±7.44§ | 79.07 ± 7.83¶ | 96.68±13.96** | <0.001 |
| Trimester 3 | 1590 | 62.32±7.04‡ | 72.19±8.11§ | 86.81 ± 8.33¶ | 103.26±13.90** | <0.001 |
| Postpartum | 1477 | 55.06±6.98‡ | 64.23±8.03§ | 79.37 ± 8.86¶ | 95.90±14.04** | <0.001 |
| Gestational weight gain (%) as per 2009 IOM GWG guidelines | ||||||
| Below | 272 | 17.2 | 22.0 | 6.1 | 14.3 | <0.001 |
| Met | 508 | 55.2 | 37.6 | 23.2 | 16.1 | |
| Exceeded | 761 | 27.6 | 40.4 | 70.7 | 69.6 | |
| Age (years)† | ||||||
| 17 to 30 | 785 | 26.48±3.35 | 27.34±2.73 | 27.23±2.79 | 26.89±2.91 | 0.17 |
| 31 to 45 | 980 | 33.36±2.61 | 34.23±2.78 | 34.65±2.96 | 34.06±2.59 | 0.07 |
| Parity (%) | ||||||
| 0 | 959 | 56.3 | 57.5 | 47.2 | 48.9 | <0.01 |
| 1 | 631 | 31.3 | 34.1 | 39.3 | 40.3 | |
| 2 + | 175 | 12.4 | 8.4 | 13.5 | 10.8 | |
| Marital status (%) | ||||||
| Married | 1691 | 89.2 | 96.1 | 95.8 | 95.2 | 0.09 |
| Unmarried | 76 | 10.8 | 3.9 | 4.2 | 4.8 | |
| Ethnicity (%) | ||||||
| Caucasian | 1424 | 68.8 | 79.9 | 82.5 | 86.6 | 0.01 |
| Other | 340 | 31.2 | 20.1 | 17.5 | 13.4 | |
| Family income as per Statistics Canada 2011 (%) | ||||||
| Low (≤$69 999) | 393 | 34.9 | 21.0 | 22.9 | 26.3 | 0.001 |
| Medium ($70 000–$99 999) | 392 | 17.5 | 20.9 | 23.7 | 30.6 | |
| High (≥$100 000) | 965 | 47.6 | 58.1 | 53.4 | 43.1 | |
| Maternal education (%) | ||||||
| Less than high school diploma | 50 | 9.5 | 2.6 | 2.7 | 2.7 | <0.001 |
| High school/diploma/certificate | 504 | 25.4 | 24.7 | 34.1 | 44.3 | |
| University degree/postgraduate degree | 1198 | 65.1 | 72.7 | 63.2 | 53.0 | |
| Gestational age (weeks)† | ||||||
| Trimester 1 | 494 | 11.85±2.47 | 11.17±2.54 | 10.73±2.38 | 10.66±2.39 | 0.14 |
| Trimester 2 | 1768 | 19.42±3.53 | 18.99±3.38 | 18.97±3.23 | 18.57±3.22 | 0.27 |
| Trimester 3 | 1749 | 32.32±1.10 | 32.41±1.30 | 32.35±1.33 | 32.44±1.15 | 0.77 |
| Delivery | 1775 | 39.43±1.22‡ | 39.69±1.12‡ | 39.65±1.19‡ | 39.37±1.20‡ | <0.01 |
| Postpartum age (weeks)† | 1642 | 12.79±2.09 | 12.80±2.25 | 12.80±2.41 | 12.63±1.72 | 0.84 |
| Breast feeding (0–3 months) (%)†† | ||||||
| Exclusive breast feeding | 730 | 55.2 | 52.3 | 42.4 | 33.1 | 0.07 |
| Mixed feeding | 768 | 44.8 | 46.8 | 57.0 | 65.0 | |
| Exclusive formula feeding | 14 | 0 | 0.9 | 0.6 | 1.9 | |
*n=1820 (underweight=69, normal=1166, overweight=391, obese=194); sample sizes within a particular characteristic may not total n=1820 due to missing responses.
†Values are reported as mean±SD.
‡,§,¶,**Values with different superscripts are different from each other within a row; data were analysed using one-way ANOVA and post hoc estimation by Tukey’s multiple comparisons test.
††Data were analysed using chi-squared test.