Faktor 1988.

Methods	Randomisation. Authors report that there was 'no selection bias in the choice of the patients'.
Participants	77 pregnant women (group Ia: 35, group Ib: 17, group II: 16, group III: 9) Inclusion criteria: mid‐trimester abortion (15‐26 weeks gestation). Exclusion criteria: none given.
Interventions	Group Ia: 1.0g oxytetracycline hydrochloride, dissolved in 16‐20 ml of normal physiological saline, intra‐amniotic. Patients received oxytocin i.v. in increasing dosage after the appearance of uterine contractions un till time of abortion. Group Ib: 1.0g oxytetracycline hydrochloride, dissolved in 16‐20 ml of normal physiological saline, intra‐amniotic. No oxytocin was given. Group II: 200 cm3 amniotic fluid was exchanged for 200 cm3 of 20% of hypertonic saline. Group III: 40 mg of PGF2α, intra‐amniotic. Group I is considered as the intervention group and group II and III are considered control groups.
Outcomes	Abortion interval, side‐effects.
Notes	Definition of abortion: expulsion of the fetus. After expulsion of the fetus, all patients underwent revision of the uterine cavity under general anaesthesia. No major complications described. For our analysis, we did not include oxytetracycline hydrochloride.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	B ‐ unclear
Blinding? All outcomes	High risk
Free of other bias?	Unclear risk	No baseline characteristics of the separate groups were provided.