Table 1 Characteristics of the patients with twin-to-twin transfusion syndrome patients with and without recipient right ventricular obstruction (RVOTO) before fetoscopic laser therapy

Maternal age at operation (year-old)

33.7 ± 4.6

31.7 ± 4.5

0.31^#

Gestational age at operation (weeks)

19.3 ± 2.4

20.7 ± 2.6

0.048^&

Gestational age at delivery (weeks)

33.2± 5.8

31.3 ± 5.5

0.16^#

RVOTO Regression after laser

4

Interval from operation to delivery (days)

92.1± 48.7

74.1±41.7

0.09^#

Quintero stage (number)

<0.001^*

I

1

30

II

5

58

III

1

65

IV

7

21

High Quintero stage (III or IV)

57.1% ( 8/14)

49.7% (86/173)

0.78*

Donor survival (number)

12

115

0.23*

Recipient survival (number)

11

130

1.0*