Table 6 Percentiles for superior vena cava end-diastolic velocity during atrial contraction (A-velocity) at 20–40 weeks of gestational age (GA)

−5.17

−3.05

−0.96

4.83

9.37

10.51

11.47

−5.32

−3.13

−0.98

4.96

9.58

10.75

11.72

−5.47

−3.20

−0.99

5.08

9.79

10.98

11.97

−5.63

−3.28

− 1.00

5.20

10.00

11.21

12.21

−5.79

−3.35

− 1.01

5.33

10.21

11.43

12.46

−5.94

−3.43

−1.03

5.45

10.41

11.66

12.70

−6.11

−3.51

− 1.04

5.57

10.62

11.88

12.94

−6.27

−3.58

− 1.05

5.69

10.82

12.10

13.17

−6.44

−3.66

−1.06

5.81

11.02

12.32

13.41

−6.61

−3.74

−1.08

5.93

11.22

12.54

13.64

−6.78

−3.82

−1.09

6.05

11.42

12.76

13.88

−6.96

−3.90

−1.10

6.16

11.61

12.97

14.11

−7.14

−3.98

−1.11

6.28

11.81

13.19

14.33

−7.32

−4.06

−1.13

6.40

12.00

13.40

14.56

−7.51

−4.14

−1.14

6.51

12.20

13.61

14.79

−7.70

− 4.22

−1.15

6.63

12.39

13.82

15.01

−7.89

−4.30

−1.17

6.74

12.58

14.03

15.23

−8.09

−4.38

−1.18

6.86

12.77

14.23

15.45

−8.30

−4.46

−1.19

6.97

12.95

14.44

15.67

−8.51

−4.55

−1.20

7.08

13.14

14.64

15.89

−8.72

−4.63

−1.22

7.20

13.33

14.84

16.11