Table 1. Descriptive analysis of the variables for children with Down syndrome, residing in Mexico City (1998–2006), included in this study.
| Cases (N=57) | Controls (N=218) | ||||
|---|---|---|---|---|---|
| Variables | N | % | N | % | OR (CI 95%) |
| Type of leukaemia | |||||
| ALL | 45 | 79.2 | NA | NA | NA |
| AML | 12 | 20.8 | NA | NA | NA |
| Maternal breastfeeding | 36 | 63.2 | 142 | 65.1 | 0.92 (0.50–1.69) |
| Family history of cancer | 33 | 57.9 | 104 | 47.7 | 1.51 (0.84–2.72) |
| Male | 27 | 47.4 | 117 | 53.7 | 0.78 (0.43–1.39) |
| Firstborn child | 8 | 14.0 | 73 | 33.5 | 0.32 (0.15–0.72) |
| Child's weight at birth >2500 g | 39 | 68.4 | 127 | 58.3 | 1.55 (0.83–2.89) |
| Infection during child's first year of life | 16 | 28.1 | 56 | 25.7 | 1.13 (0.59–2.17) |
| Hospitalisation for infection during child's first year of life | 14 | 24.5 | 29 | 13.3 | 2.22 (1.08–4.58) |
| Gastrointestinal illness | 3 | 20.0 | 7 | 24.1 | 0.943* |
| Respiratory tract infection | 9 | 60.0 | 16 | 55.2 | |
| Other | 3 | 20.0 | 6 | 20.7 | |
| Presence of allergies in child | 17 | 29.8 | 75 | 34.4 | 0.81 (0.43–1.52) |
| Low standard of living | 45 | 78.9 | 153 | 70.2 | 1.59 (0.79–3.21) |
| Cardiovascular illness in child | 7 | 12.3 | 57 | 26.1 | 0.39 (0.17–0.92) |
| Age of mother at delivery >35 years | 22 | 38.6 | 76 | 34.9 | 1.17 (0.64–2.14) |
| Smoking by father during wife's pregnancy | 32 | 56.1 | 128 | 58.7 | 0.90 (0.50–1.62) |
| Smoking by mother during pregnancy | 15 | 26.3 | 63 | 28.9 | 0.88 (0.45–1.70) |
| Alcohol consumption by father before pregnancy | 52 | 91.2 | 187 | 85.8 | 1.72 (0.64–4.65) |
| Alcohol consumption by mother during pregnancy | 30 | 52.6 | 164 | 75.2 | 0.36 (0.20–0.67) |
ALL=acute lymphoblastic leukaemia; AML=acute myeloblastic leukaemia; CI=confidence intervals; NA=not applicable; OR=odds ratio.
*P-value.