Measures of association between offspring and maternal characteristics, and being small for gestational age (SGA), in the whole population of babies and in strata of gestational age in Sweden 1987–1993
| SGA | SGA term | SGA preterm | SGA post-term | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Unadjusted model | Unadjusted model | Unadjusted model | Unadjusted model | |||||||||
| OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI | |||||
| Newborn babies | ||||||||||||
| Male (ref) | ||||||||||||
| Female | 1.01 | (0.98 | 1.04) | 1.01 | (0.97 | 1.04) | 0.86 | (0.84 | 0.88) | 0.85 | (0.77 | 0.94) |
| Birth order | ||||||||||||
| First (ref) | ||||||||||||
| Second | 0.48 | (0.47 | 0.50) | 0.49 | (0.47 | 0.51) | 0.60 | (0.59 | 0.62) | 0.48 | (0.42 | 0.54) |
| ≥Third | 0.49 | (0.47 | 0.51) | 0.48 | (0.46 | 0.50) | 0.72 | (0.70 | 0.74) | 0.47 | (0.41 | 0.54) |
| Gestational age | 0.80 | (0.79 | 0.81) | 0.87 | (0.85 | 0.88) | 0.86 | (0.85 | 0.87) | 1.77 | (1.61 | 1.95) |
| Birth intervals | ||||||||||||
| 1–2 years (ref) | ||||||||||||
| <1 year | 1.81 | (1.53 | 2.13) | 1.74 | (1.42 | 2.12) | 0.84 | (0.56 | 1.24) | 3.35 | (2.18 | 5.13) |
| >2 years | 0.98 | (0.92 | 1.05) | 0.97 | (0.90 | 1.05) | 1.16 | (1.00 | 1.35) | 0.95 | (0.77 | 1.16) |
| ‘Only child’ | 1.40 | (1.32 | 1.05) | 1.37 | (1.29 | 1.46) | 1.47 | (1.29 | 1.67) | 1.16 | (0.97 | 1.38) |
| First child | 0.99 | (0.93 | 1.05) | 0.99 | (0.93 | 1.07) | 1.03 | (0.89 | 1.19) | 0.94 | (0.78 | 1.15) |
| Previous child SGA | ||||||||||||
| No (ref) | ||||||||||||
| Yes | 5.48 | (4.87 | 6.17) | 5.45 | (4.74 | 6.28) | 4.75 | (3.61 | 6.24) | 3.95 | (2.49 | 6.42) |
| ‘Only child’ | 1.47 | (1.42 | 1.53) | 1.46 | (1.40 | 1.52) | 1.45 | (1.33 | 1.58) | 1.18 | (1.05 | 1.33) |
| First child | 1.04 | (0.99 | 1.09) | 1.06 | (1.01 | 1.12) | 1.01 | (0.91 | 1.13) | 0.97 | (0.84 | 1.11) |
| Maternal age | ||||||||||||
| 25–34 (ref) | ||||||||||||
| <20 | 1.41 | (1.33 | 1.49) | 1.42 | (1.33 | 1.53) | 1.44 | (1.38 | 1.50) | 1.51 | (1.25 | 1.83) |
| 20–24 | 1.09 | (1.05 | 1.13) | 1.09 | (1.04 | 1.14) | 1.16 | (1.13 | 1.19) | 1.12 | (0.99 | 1.27) |
| >35 | 1.23 | (1.18 | 1.29) | 1.18 | (1.12 | 1.25) | 1.31 | (1.27 | 1.36) | 1.00 | (0.86 | 1.17) |
| Hypertension | ||||||||||||
| No (ref) vs yes | 4.02 | (3.55 | 4.55) | 3.05 | (2.58 | 3.61) | 2.73 | (2.45 | 3.04) | 2.02 | (0.99 | 4.13) |
| Smoking | ||||||||||||
| Non-smoker (ref) | ||||||||||||
| Light smoker | 2.08 | (2.01 | 2.16) | 2.27 | (2.17 | 2.37) | 1.30 | (1.26 | 1.33) | 1.86 | (1.64 | 2.12) |
| Heavy smoker | 2.56 | (2.46 | 2.67) | 2.84 | (2.70 | 2.98) | 1.53 | (1.48 | 1.58) | 2.42 | (2.10 | 2.79) |
| Missing | 1.66 | (1.57 | 1.76) | 1.56 | (1.45 | 1.67) | 1.70 | (1.64 | 1.76) | 1.59 | (1.32 | 1.92) |
| Marital status | ||||||||||||
| Married or cohabiting (ref) | ||||||||||||
| Divorced or widowed | 1.52 | (1.41 | 1.63) | 1.52 | (1.40 | 1.66) | 1.51 | (1.43 | 1.59) | 1.33 | (1.04 | 1.71) |
| Single | 1.31 | (1.27 | 1.35) | 1.31 | (1.27 | 1.36) | 1.19 | (1.17 | 1.22) | 1.25 | (1.13 | 1.38) |
| Maternal origin | ||||||||||||
| Born in Sweden (ref) | ||||||||||||
| Not born in Sweden | 1.27 | (1.21 | 1.32) | 1.30 | (1.23 | 1.36) | 1.07 | (1.04 | 1.11) | 1.56 | (1.37 | 1.77) |
| Missing | 1.66 | (1.49 | 1.84) | 1.71 | (1.51 | 1.94) | 1.35 | (1.24 | 1.47) | 2.74 | (2.08 | 3.61) |
| Maternal education | ||||||||||||
| University (ref) | ||||||||||||
| Secondary | 1.14 | (1.10 | 1.19) | 1.17 | (1.12 | 1.23) | 1.13 | (1.10 | 1.17) | 1.07 | (0.94 | 1.22) |
| Primary | 1.49 | (1.42 | 1.56) | 1.53 | (1.45 | 1.62) | 1.35 | (1.31 | 1.39) | 1.51 | (1.30 | 1.76) |
| Missing | 1.67 | (1.57 | 1.77) | 1.78 | (1.66 | 1.92) | 1.42 | (1.36 | 1.49) | 1.92 | (1.59 | 2.31) |
Values are ORs and (95% CI). Crude models.
SGA, small for gestational age.