Time to reach an Apgar score of >6 (min) | Measures of cognition | Measure of educationSchool grade(n = 167 117) | ||||||||||
Logic score(n = 134 596) | Synonym score(n = 133 858) | Spatial score(n = 133 825) | Technical score(n = 124 149) | IQ score(n = 136 788) | ||||||||
Mean reduction (z-score) | p* | Mean reduction (z-score) | p* | Mean reduction (z-score) | p* | Mean reduction (z-score) | p* | Mean reduction (z-score) | p* | Mean reduction (z-score) | p* | |
Unadjusted | ||||||||||||
<1 | Ref | Ref | Ref | Ref | Ref | Ref | ||||||
1–5 | 0.017 (−0.014–0.048) | 0.006 | −0.014 (−0.043–0.015) | 0.991 | −0.017 (−0.048–0.015) | 0.040 | 0.045 (0.013–0.076) | <0.001 | 0.013 (−0.017–0.043) | 0.023 | −0.005 (−0.032–0.022) | 0.019 |
>5 | 0.107 (0.036–0.179) | 0.038 (−0.028–0.105) | 0.108 (0.035–0.181) | 0.094 (0.022–0.167) | 0.091 (0.021–0.161) | 0.129 (0.067–0.192) | ||||||
Adjusted for antenatal†§ factors | ||||||||||||
<1 | Ref | Ref | Ref | Ref | Ref | Ref | ||||||
1–5 | 0.036 (0.005–0.067) | <0.001 | 0.011 (−0.018–0.039) | 0.087 | −0.001 (−0.032–0.031) | 0.040 | 0.057 (0.026–0.089) | <0.001 | 0.035 (0.005–0.065) | <0.001 | 0.011 (−0.016–0.038) | 0.001 |
>5 | 0.120 (0.049–0.191) | 0.061 (−0.005–0.127) | 0.119 (0.047–0.192) | 0.100 (0.028–0.173) | 0.109 (0.039–0.178) | 0.138 (0.076–0.200) | ||||||
Adjusted for antenatal† and intrapartum/neonatal factors‡ | ||||||||||||
<1 | Ref | Ref | Ref | Ref | Ref | Ref | ||||||
1–5 | 0.039 (0.008–0.070) | <0.001 | 0.016 (−0.013–0.045) | 0.037 | −0.003 (−0.034–0.029) | 0.057 | 0.058 (0.026–0.089) | <0.001 | 0.039 (0.009–0.069) | <0.001 | 0.019 (−0.008–0.046) | <0.001 |
>5 | 0.123 (0.052–0.194) | 0.067 (0.001–0.133) | 0.116 (0.043–0.188) | 0.096 (0.024–0.169) | 0.112 (0.042–0.181) | 0.145 (0.083–0.207) | ||||||
Adjusted for antenatal†, intrapartum/neonatal factors‡ and social factors§ | ||||||||||||
<1 | Ref | Ref | Ref | Ref | Ref | Ref | ||||||
1–5 | 0.034 (0.005–0.063) | 0.001 | 0.011 (−0.015–0.038) | 0.169 | −0.007 (−0.037–0.024) | 0.188 | 0.052 (0.022–0.083) | <0.001 | 0.033 (0.005–0.061) | 0.001 | 0.010 (−0.015–0.034) | 0.002 |
>5 | 0.092 (0.025–0.158) | 0.036 (−0.025–0.097) | 0.091 (0.021–0.161) | 0.071 (0.001–0.140) | 0.081 (0.017–0.145) | 0.109 (0.053–0.166) |
*p for trend.
†Parity, pre-eclampsia, birth weight, length and head circumference.
‡Mode of delivery, maternal or infant infection, season and year of birth.
§Maternal and paternal education status, occupation and age.