Weiniger 2007.

Methods	RCT.
Participants	Inclusion criteria: All eligible nulliparous women who requested ECV after 37 weeks' gestation during the period from September 2002 to May 2006 were approached for recruitment before the ECV procedure. Inclusion criteria included American Society of Anesthetists status I to II at 37 to 40 weeks' gestation, and no fetal abnormality. N = 70. Exclusion criteria: women with a breech presenting fetus who requested elective caesarean delivery, either after failed ECV at another institution or because they did not wish to try ECV at all, were not included or followed up, and data regarding these women were not collected. Women with any of the following were excluded: previous uterine surgery or uterine anomaly, contraindication for vaginal delivery, contraindications for regional analgesia, woman's refusal of regional analgesia, neuropathy, severe back pain with neurological radiation, poor communication and morbid obesity (body mass index > 40 kg/m2).
Interventions	Intervention:regional analgesia (C) + tocolytic. Spinal analgesia (bupivacaine 7.5 mg). N = 36. Comparison: no regional analgesia + tocolytic. N = 34. Both groups received 50 mg ritodrine or 20 mg nifedipine sublingually.
Outcomes	Successful ECV.
Notes	In spinal group: 1 woman excluded as morbidly obese, 1 women requested to not have spinal after randomisation. In placebo group: 1 woman excluded as morbidly obese, 1 refused ECV after randomisation.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Allocation cards randomly inserted into envelopes by a physician not involved in the study.
Allocation concealment (selection bias)	Unclear risk	Study allocation was by sequentially numbered sealed envelopes containing a concealed allocation card designating the participant to receive (group S), or not receive (group N), spinal analgesia. Allocation sequence was concealed until after enrolment, and informed consent was obtained before study assignment of the participant was revealed.
Blinding of participants and personnel (performance bias) All outcomes	High risk	It is not possible to blind people to regional analgesia.
Blinding of outcome assessment (detection bias) All outcomes	High risk	It is not possible to blind people to regional analgesia.
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 women in each group were excluded from the analysis (1 in each group declined ECV or the intervention, and 1 protocol violation was reported in each group). This was considered insufficient to impact the analysis.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Unclear risk	Women in the intervention group were significantly younger than those in the control group, but other baseline characteristics were similar between groups (height, weight, weight gain, EFW, GA, amniotic fluid volume, placental position, fetal presentation, position of fetal spine, tocolytic used).