Li 2016.

Study characteristics
Methods	Randomization using sealed, opaque and numbered envelopes, with a randomization table
Participants	92 women with CSP
Interventions	All participants underwent UACE (MTX 50 mg infused bilaterally into the gelatin sponge particles). Within 24–48 hours, suction curettage under hysteroscopy monitoring (31A,17B. 48 cases, age: > 35y, n = 29; < 35y, n = 19), or suction curettage under ultrasonography monitoring (28A,16B. 44 cases, age: > 35y, n = 31; < 35y, n = 13) (A: diameter of the gestational sac ≤ 3.0 cm; B: diameter of the gestational sac > 3.0cm)
Outcomes	Primary outcomes: success after initial treatment complications (including heavy bleeding, uterine perforation, pelvic infection, incomplete abortion, and uterine adhesion) Secondary outcomes: adverse effects (including low fever (37.3–38.5 °C) and abdominal pain, and all the participants had these adverse effects) time to normalize β‐hCG
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "a sealed opaque envelope with a serial number on the surface and a random number inside."
Allocation concealment (selection bias)	Low risk	Quote: "The random number had been packed in the serially numbered envelopes by hospital staff members who had no contact with patients, clinicians, and investigators."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Clinicians were not masked to group assignment, but participants and data analysts were."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Clinicians were not masked to group assignment, but participants and data analysts were."
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data.
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit judgement.
Other bias	Unclear risk	Insufficient information to assess whether an important risk of bias existed.