Table 1.
Characteristics of the mothers and their sons at enrollment or during follow-up. Tapachula, Chiapas, Mexico 2002–2005
| Overall | Urban residence |
Rural residence |
|||
|---|---|---|---|---|---|
| Characteristics | n | Median (IQR) or % n = 747 |
Median (IQR) or % n = 448 |
Median (IQR) or % n = 299 |
p- value* |
| Mothers | |||||
|
| |||||
| Age | 747 | 23.7 (7.2) | 24.0 (7.0) | 23.2 (7.2) | 0.05 |
| Education (year) | <0.01 | ||||
| 0 – 6 | 262 | 35.1 | 27.9 | 45.8 | |
| 7 – 9 | 236 | 31.6 | 31.7 | 31.4 | |
| 10 – 12 | 173 | 23.2 | 26.6 | 18.1 | |
| > 12 | 76 | 10.2 | 13.8 | 4.7 | |
| Parity | 0.39 | ||||
| 1 | 307 | 41.1 | 40.6 | 41.8 | |
| 2 | 261 | 34.9 | 33.7 | 36.8 | |
| 3+ | 179 | 24.0 | 25.7 | 21.4 | |
| Trimester of first prenatal visit | 0.82 | ||||
| Never | 250 | 33.5 | 32.6 | 34.8 | |
| 1st | 330 | 44.2 | 44.9 | 43.1 | |
| After first | 167 | 22.4 | 22.5 | 22.1 | |
| Type of delivery | 0.98 | ||||
| Caesarean | 277 | 37.1 | 37.1 | 37.1 | |
| Vaginal | 470 | 62.9 | 62.9 | 62.9 | |
| Marital status | 0.75 | ||||
| Married | 357 | 47.8 | 46.7 | 49.5 | |
| Not married with partner | 320 | 42.8 | 43.8 | 41.5 | |
| Single | 70 | 9.4 | 9.6 | 9.0 | |
| Hospital of recruitment | <0.01 | ||||
| Social Security | 368 | 49.3 | 55.8 | 39.5 | |
| Ministry of Health | 379 | 50.7 | 44.2 | 60.5 | |
| Mom smoked ever | <0.01 | ||||
| Yes | 146 | 19.5 | 23.2 | 14.0 | |
| No | 601 | 80.5 | 76.8 | 86.0 | |
| Poverty index | 0.34 | ||||
| Poorest | 531 | 71.1 | 69.4 | 73.6 | |
| Less poor | 139 | 18.6 | 20.3 | 16.1 | |
| Not poor | 77 | 10.3 | 10.3 | 10.4 | |
| Residence area | |||||
| Urban | 448 | 60.0 | 100.0 | 0.0 | |
| Rural | 299 | 40.0 | 0.0 | 100.0 | |
| Type of sanitation system | <0.01 | ||||
| Sewer system | 555 | 74.3 | 88.6 | 52.8 | |
| Septic tank | 126 | 16.9 | 7.4 | 31.1 | |
| Latrine | 44 | 5.9 | 2.9 | 10.4 | |
| Other | 22 | 2.9 | 1.1 | 5.7 | |
| House's type of floor | <0.01 | ||||
| Dirt/Soil | 202 | 27.0 | 17.2 | 41.8 | |
| Concrete | 487 | 65.2 | 73.0 | 53.5 | |
| Mosaic/other | 58 | 7.8 | 9.8 | 4.7 | |
| Number of inhabitants in the household | 747 | 5.0 (2.0) | 5.0 (2.0) | 5.0 (2.0) | 0.99 |
| p,p'-DDT (µg/g) | 747 | 0.27 (0.67) | 0.19 (0.29) | 0.66 (1.48) | <0.01 |
| p,p'-DDE (µg/g) | 747 | 2.70 (4.50) | 2.21 (2.90) | 4.27 (6.95) | <0.01 |
| Sons | |||||
| Birth season | 0.63 | ||||
| Winter | 142 | 19.0 | 17.9 | 20.7 | |
| Spring | 212 | 28.4 | 27.7 | 29.4 | |
| Summer | 216 | 28.9 | 30.1 | 27.1 | |
| Autumn | 177 | 23.7 | 24.3 | 22.7 | |
| Gestational age at birth (wk) | 0.45 | ||||
| ≤ 37 | 25 | 3.3 | 2.9 | 4.0 | |
| 37.1 – 39.9 | 277 | 37.1 | 38.6 | 34.8 | |
| ≥ 40 | 445 | 59.6 | 58.5 | 61.2 | |
| WfA < −2.00 SD | 0.05 | ||||
| No | 640 | 85.7 | 87.7 | 82.6 | |
| Yes | 107 | 14.3 | 12.3 | 17.4 | |
| Child attended well care | <0.01 | ||||
| No | 356 | 47.7 | 53.8 | 38.5 | |
| Yes | 391 | 52.3 | 46.2 | 61.5 | |
| Type of drinking water | <0.01 | ||||
| Bottle | 87 | 11.6 | 15.4 | 6.0 | |
| Boiled | 647 | 86.6 | 83.3 | 91.6 | |
| Raw | 13 | 1.7 | 1.3 | 2.3 | |
| Child's age at introduction of other milk (mo) | <0.01 | ||||
| ≤ 1 | 255 | 34.1 | 35.5 | 32.1 | |
| 1.1 – 4.0 | 182 | 24.4 | 27.9 | 19.1 | |
| > 4.0 | 310 | 41.5 | 36.6 | 48.8 | |
| Ever exclusively breastfed | 1.00 | ||||
| No | 120 | 16.1 | 16.1 | 16.1 | |
| Yes | 627 | 83.9 | 83.9 | 83.9 | |
| Any breastfeeding (mo) | 747 | 11.0 (12.9) | 9.0 (12.0) | 12.0 (12.0) | <0.01 |
| Exclusive breastfeeding (mo) | 747 | 0.10 (0.97) | 0.13 (0.97) | 0.10 (0.97) | 0.15 |
IQR, interqartile range; WfA, weight-for-age
*
P-values from Pearson’s Chi2 and Fisher’s exact test comparing participants from urban versus rural areas