Nor Azlin 2008.

Methods	RCT.
Participants	Inclusion criteria: singleton term pregnancies with a breech presentation. N = 86. Exclusion criteria: oligohydramnios, macrosomia, presence of a contraindication for vaginal delivery, previous caesarean delivery, multiple pregnancy, hypertension in pregnancy, rhesus‐negative mother, previous history of abruptio placenta, lethal fetal anomaly, contraindication against nifedipine or terbutaline.
Interventions	Intervention:tocolytic: nifedipine ‐ calcium channel blocker (A2) ‐ oral. Oral nifedipine (20 mg). N = 43 (nulliparous 18, multiparous 25). Comparison:tocolytic: terbutaline ‐ beta stimulant (A1) ‐ parenteral. IV terbutaline (50 μg). N = 43 (nulliparous 21, multiparous 22) (6 lost to further follow‐up).
Outcomes	Successful ECV, difficult ECV, palpitations, hypotension, method of delivery, perinatal morbidity.
Notes	6 successful ECVs from the terbutaline group were lost to follow‐up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computerised random‐number generator.
Allocation concealment (selection bias)	Low risk	Sealed, opaque, numbered envelopes in sequence.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Clinicians doing ECV were blinded to the tocolytic drug, women were not blinded because 1 group had oral administration and the other IV. Clinicians doing the ECV were in control of the success rate and were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Clinicians doing ECV were blinded to the tocolytic drug, women were not blinded because 1 group had oral administration and the other IV. Clinicians doing the ECV were in control of the success rate and were blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Among those who had successful ECV, 6 from terbutaline group were lost to follow‐up, so although all women were included in the assessment of the success of ECV, the outcome of CS is at risk of bias.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Low risk	The study was not stopped early. Baseline characteristics were similar between groups in maternal age, GA, AFI, parity and type of breech presentation. No other biases were identified.