Table 5.
Association between conditional variables and neurodevelopmental delay at 12 months old in girls
| [Model 1] Conditional variables at birth, 4, 7 and 10 months old | Total | Communication | Gross motor | Fine motor | Problem solving | Personal-Social |
| 1,117/8,211 (13.6 %) | 199/8,253 (2.4 %) | 540/8,254 (6.5 %) | 235/8,254 (2.8 %) | 348/8,244 (4.2 %) | 202/8,229 (2.5 %) | |
| Length at birth | 1.04 (0.97–1.12) | 0.92 (0.77–1.11) | 1.05 (0.94–1.17) | 1.05 (0.88–1.24) | 1.01 (0.88–1.16) | 0.99 (0.82–1.18) |
| Weight at birth | 0.89 (0.83–0.96) | 0.96 (0.80–1.16) | 0.87 (0.78–0.97) | 0.87 (0.73–1.03) | 0.86 (0.75–0.99) | 0.94 (0.78–1.13) |
| cLength at 4 months old | 0.90 (0.84–0.96) | 0.85 (0.73–1.01) | 1.02 (0.92–1.12) | 0.77 (0.66–0.90) | 0.82 (0.73–0.93) | 0.78 (0.67–0.92) |
| crWeight at 4 months old | 0.96 (0.89–1.04) | 0.80 (0.66–0.97) | 0.94 (0.84–1.05) | 0.97 (0.81–1.16) | 0.91 (0.79–1.06) | 0.88 (0.72–1.06) |
| cLength at 7 months old | 1.16 (1.07–1.26) | 1.17 (0.95–1.43) | 1.21 (1.08–1.37) | 1.06 (0.91–1.29) | 1.14 (0.98–1.33) | 1.10 (0.91–1.35) |
| crWeight at 7 months old | 1.10 (0.98–1.23) | 0.91 (0.67–1.20) | 1.19 (1.00-1.39) | 0.92 (0.70–1.21) | 1.01 (0.81–1.25) | 0.98 (0.73–1.28) |
| cLength at 10 months olda | 0.97 (0.88–1.08) | 0.94 (0.73–1.21) | 1.04 (0.89–1.21) | 1.04 (0.82–1.32) | 1.07 (0.88–1.29) | 0.87 (0.69–1.12) |
| crWeight at 10 months oldb | 1.02 (0.91–1.18) | 0.87 (0.73–1.17) | 1.03 (0.87–1.27) | 1.17 (0.86–1.65) | 1.23 (0.94–1.63) | 0.90 (0.75–1.23) |
| [Model 2] Conditional variables at birth, 4 and 7 months old | Total | Communication | Gross motor | Fine motor | Problem solving | Personal-Social |
| 1,751/13,220 (13.2 %) | 313/13,289 (2.4 %) | 810/13,293 (6.1 %) | 371/13,292 (2.8 %) | 544/13,278 (4.1 %) | 317/13,250 (2.4 %) | |
| Length at birth | 1.01 (0.95–1.07) | 0.93 (0.80–1.08) | 1.06 (0.97–1.16) | 1.01 (0.88–1.16) | 0.94 (0.84–1.05) | 0.98 (0.85–1.14) |
| Weight at birth | 0.94 (0.88–0.99) | 0.95 (0.82–1.10) | 0.86 (0.78–0.94) | 0.96 (0.84–1.10) | 0.96 (0.86–1.07) | 0.95 (0.82–1.10) |
| cLength at 4 months old | 0.90 (0.86–0.95) | 0.85 (0.75–0.97) | 1.01 (0.94–1.10) | 0.83 (0.74–0.94) | 0.82 (0.75–0.91) | 0.81 (0.71–0.92) |
| crWeight at 4 months old | 0.93 (0.88–0.99) | 0.78 (0.67–0.92) | 0.92 (0.83–1.01) | 0.96 (0.84–1.11) | 0.89 (0.79–0.99) | 0.94 (0.81–1.09) |
| cLength at 7 months old | 1.17 (1.10–1.26) | 1.13 (0.96–1.35) | 1.22 (1.10–1.35) | 1.15 (0.98–1.34) | 1.14 (1.01–1.30) | 1.07 (0.92–1.27) |
| crWeight at 7 months old | 1.10 (0.99–1.21) | 0.89 (0.72–1.13) | 1.19 (1.03–1.37) | 0.94 (0.76–1.18) | 1.07 (0.89–1.27) | 0.98 (0.78–1.24) |
| [Model 3] Conditional variables at birth, 4 and 10 months old | Total | Communication | Gross motor | Fine motor | Problem solving | Personal-Social |
| 2,669/20,756 (12.9 %) | 441/20,857 (2.1 %) | 1,263/20,864 (6.1 %) | 537/20,858 (2.6 %) | 827/20,837 (4.0 %) | 463/20,799 (2.2 %) | |
| Length at birth | 1.02 (0.97–1.07) | 0.95 (0.84–1.07) | 1.03 (0.95–1.10) | 1.03 (0.92–1.15) | 1.03 (0.94–1.12) | 1.04 (0.92–1.17) |
| Weight at birth | 0.92 (0.88–0.97) | 0.95 (0.84–1.08) | 0.92 (0.85–0.99) | 0.89 (0.79–0.99) | 0.91 (0.83–0.99) | 0.87 (0.77–0.98) |
| cLength at 4 months old | 0.91 (0.88–0.95) | 0.85 (0.77–0.95) | 0.95 (0.89–1.01) | 0.88 (0.80–0.97) | 0.86 (0.80–0.93) | 0.87 (0.78–0.97) |
| crWeight at 4 months old | 0.98 (0.93–1.03) | 0.86 (0.76–0.99) | 0.98 (0.91–1.06) | 0.94 (0.83–1.06) | 0.96 (0.87–1.05) | 0.88 (0.78–1.01) |
| cLength at 10 months olda | 1.06 (1.01–1.12) | 0.99 (0.88–1.13) | 1.06 (0.98–1.15) | 1.08 (0.96–1.22) | 1.15 (1.04–1.26) | 1.02 (0.90–1.16) |
| crWeight at 10 months oldb | 1.05 (0.99–1.13) | 0.98 (0.84–1.15) | 1.04 (0.94–1.14) | 0.96 (0.85–1.11) | 1.05 (0.93–1.18) | 0.95 (0.83–1.11) |
Data represent the adjusted relative risk (95 % confidence interval). All of the conditional variables and the following covariates were included together in the model: maternal age and smoking, maternal and paternal education, family income, and home speech stimulation. a,bThe values of the variables were different between the models because these variables were estimated from different combinations of the previous data ([model 1] at birth, 4 and 7 months old; [model 3] at birth and 4 months old).
cLength conditional length; crWeight conditional relative weight