Comparison of individuals whose fetal crown–rump length, biparietal diameter and birth weight were and were not all determined
| All measurements available (n=790 unless stated) | All measurements not available (n=1210 unless stated) | |
| Male sex | 53% (411/782) | 49% (536/1096) |
| Maternal smoker in first trimester | 28% (218) | 31% (375) |
| Median number of cigarettes smoked | 15 (10–20) | 15 (10–20) |
| Mother quit after first trimester | 11% (89) | 9% (114) |
| Father smoker | 23% (127/560) | 23% (184/817) |
| Mean (SD) maternal height (m) | 1.63 (0.06) | 1.63 (0.06) |
| Mean (SD) maternal plasma α-tocopherol (μg/ml) | 9.7 (2.8) n=788 | 10.3 (3.0) n=1202 |
| Median (range) SIMD quintile | 4 (1–5) | 4 (1–5) |
No differences were seen between the groups.
SIMD, Scottish Index for Multiple Deprivation.