| Variable | Eik-Nes et al 1984<7> | Bakketeig et al 1984<8> | Neilson et al 1984<9> | Ewigman et al 1993<10> |
| Type of population | General | General | Low-risk | Low-risk |
| Sample size | ||||
| Experimental Group | 819 | 510 | 433 | 7,812 |
| Control Group | 809 | 499 | 444 | 7,718 |
| Interventions | ||||
| Experimental Group | Measurement of BPD at 16 weeks and of BPD and AD at 32 weeks. | Measurement of BPD at 19 weeks and of BPD and AD at 32 weeks. | Measurement of CRL and TA at 24 and 35 weeks. | Measurement of placental location, BPD, AC,
FL and detailed
anatomical survey at 18-20 weeks and at 31-33 weeks. |
| Control Group | Routine care | Routine care | Done, but results not reported to doctor | Routine care |
1 BPD = biparietal diameter, AD = Abdominal diameter, CRL = crown-rump length, TA = trunk area, AC = abdominal circumference, FL = femur length