Increases in spirometric indices at age 5 years per mm increase in fetal size
| 5-Year outcome | Crown–rump length (mm) | Biparietal diameter (mm) | Femur length (mm) | ||||||
| Coefficient | 95% CI | p Value | Coefficient | 95% CI | p Value | Coefficient | 95% CI | p Value | |
| FEV1 (ml) | 4 n=217 | 1 to 7 | 0.009 | 4 n=363 | −2 to 10 | 0.179 | 2 n=358 | −5 to 8 | 0.601 |
| FVC (ml) | 5 n=282 | 2 to 9 | 0.001 | 8 n=478 | 1 to 14 | 0.018 | 3 n=471 | −4 to 9 | 0.467 |
| FEF25–75 (ml/s) | 0.006 n=282 | 0.000 to 0.012 | 0.069 | 0.003 n=487 | −0.036 to 0.077 | 0.468 | 0.008 n=468 | −0.007 to 0.022 | 0.290 |
| Postbronchodilator FEV1 (ml) | 5 n=129 | 1 to 9 | 0.011 | 10 n=205 | 1 to 19 | 0.026 | 7 n=203 | −3 to 17 | 0.165 |
The models adjusted for gestational age at scan, sex, maternal smoking status at first trimester scan, history of maternal asthma, maternal height, Scottish Index of Multiple Deprivation (SIMD), birth weight and child's height aged 5 years.
FEF25–75, forced expiratory flow between 25% and 75% of FVC; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.