Table 1.
Baseline socio-demographic and lifestyle characteristics of the participants in the study according to their pre-pregnancy body mass index (BMI)
| Characteristic | Full sample (N) 1 | Normal weight (BMI 18.5-24.9 kg/m 2 ) | Overweight (BMI 25–29.9 kg/m 2 ) | p* | Obese (BMI ≥ 30 kg/m 2 ) | p † |
|---|---|---|---|---|---|---|
| N (%) | 1996 (100%) | 1313 (65.8%) | 472 (23.6%) | 211 (10.6) | ||
| Demographics | ||||||
| Maternal age | 0.279 | 0.261 | ||||
| ≤34 years old | 1539 (78.3) | 1011 (78.5) | 356 (76.1) | 172 (81.9) | ||
| ≥35 years old | 427 (21.7) | 277 (21.5) | 112 (23.9) | 38 (18.1) | ||
| Ethnicity | 0.025 | 0.005 | ||||
| Caucasian | 1602 (80.4) | 1027 (78.4) | 392 (83.2) | 183 (86.7) | ||
| Other | 390 (19.6) | 283 (21.6) | 79 (16.8) | 28 (13.3) | ||
| Household income | 0.451 | 0.035 | ||||
| ≤ $39,000 | 139 (7.2) | 87 (6.8) | 34 (7.4) | 18 (8.7) | ||
| $40,000- $79,999 | 394 (20.3) | 243 (19.0) | 98 (21.4) | 53 (25.7) | ||
| ≥ $80,000 | 1406 (72.5) | 946 (74.1) | 325 (71.1) | 135 (65.5) | ||
| Education | <0.001 | <0.001 | ||||
| High school | 190 (9.5) | 108 (8.3) | 47 (10.0) | 35 (16.6) | ||
| Post-secondary | 1802 (90.5) | 1201 (91.7) | 425 (90.0) | 176 (83.4) | ||
| Marital status | 0.961 | 0.450 | ||||
| Single | 92 (4.6) | 59 (4.5) | 21 (4.4) | 12 (5.6) | ||
| Married/common law | 1901 (95.4) | 1251 (95.5) | 451 (95.6) | 199 (94.3) | ||
| Lifestyle | ||||||
| Smoking during pregnancy | 0.416 | 0.033 | ||||
| No | 1894 (94.9) | 1248 (95.0) | 453 (96.0) | 193 (91.5) | ||
| Yes | 102 (5.1) | 65 (5.0) | 19 (4.0) | 18 (8.5) | ||
| Alcohol use in pregnancy2 | 0.018 | 0.288 | ||||
| No | 1981 (99.2) | 1306 (99.5) | 464 (98.3) | 211 (100.0) | ||
| Yes | 15 (0.8) | 7 (0.5) | 8 (1.7) | 0 (0.0) | ||
| Recreational drugs use in pregnancy | 0.285 | 0.571 | ||||
| No | 1992 (99.8) | 1311 (99.8) | 470 (99.6) | 211 (100.0) | ||
| Yes | 4 (0.2) | 2 (0.2) | 2 (0.4) | 0 (0.0) | ||
Data presented as n (%) (χ2 test) for categorical variables or mean (95% confidence intervals) (analysis of variance ANOVA) for continuous variables.
*Comparison between normal weight and overweight women.
†Comparison between normal weight and obese women.
1May not add to total number (N = 1996) due to missing.
2Refers to consumption of ≥3 drinks on any one occasion at any time during pregnancy.
Omnibus test p-values were significant for ethnicity (p = 0.004), education (p = 0.001), smoking (p = 0.043), and alcohol use in pregnancy (p = 0.018) and not significant for any of the other variables included in the table.
Percentages are calculated per column for each variable.
BMI, body mass index.