Ultrasonographic findings in 16 fetuses
| Gestational week | |||||
|---|---|---|---|---|---|
| 6+ | 7+ | 8+ | 9+ | 10+ | |
| Data are mean (SD). | |||||
| *p<0.05 versus 6+ weeks; **p<0.001 versus 6+ weeks; †p<0.05 versus 7+ and 8+ weeks. | |||||
| ICT%, proportion of isovolumetric contraction time; IRT%, proportion of isovolumetric relaxation time. | |||||
| Fetal heart rate (beats/min) | 118 (10) | 156 (9)** | 173 (8)** | 172 (7)** | 167 (5)** |
| IRT% | 39.8 (2.6) | 19.2 (6.2)** | 17.1 (6.1)** | 14.5 (1.4)** | 12.5 (1.1)** |
| ICT% | 13.4 (2.3) | 17.3 (4.7) | 13.2 (4.0) | 8.5 (2.5)† | 7.1 (1.4)† |
| Outflow | |||||
| Maximum velocity (cm/s) | 15.5 (5.3) | 21.3 (9.9) | 25.8 (7.8)* | 28.9 (6.9)* | 29.3 (5.0)* |
| Mean velocity (cm/s) | 3.6 (1.5) | 5.7 (3.6) | 8.4 (3.0)* | 9.8 (1.8)** | 8.8 (1.7)** |