Table 1 The patients’ characteristics and demographics

Maternal age (years)

32.84 ± 4.37

Gravidity (times)

4.49 ± 1.41

Prior abortion (times)

2.00 (0.00–6.00)^a

Prior CS (times)

1.00 (1.00–2.00)^a

Interval between CS and CSP (months)

71.44 ± 46.17

Gestational age (days)

83.18 ± 28.14

Interval between D&C and hysteroscopic surgery (days)

22.33 ± 13.08

Serum β-hCG level before hysteroscopic surgery (IU/L)

2623.00 (0.55–39,992.00)^a

Size of the residual gestational tissue before hysteroscopic surgery (cm)

3.44 ± 1.12

Thickness of the lower uterine segment (mm)

1.20 (0.50–8.00)^a