Gil 2011.

Methods	Potential women were identified through obstetric records and approached, in person or by phone, to determine if they met the inclusion criteria. 41 women were invited to attend; 4 declined, 3 did not attend the first follow‐up. 34 women randomised to either Global Postural Re‐education (GPR) treatment or usual prenatal care.
Participants	Women selected from those receiving prenatal care in 3 health centres and those who attended lectures in preparation for birth at a private hospital in Campinas, Brazil. Both groups of women were similar in most of the characteristics studied on admission to the study: in the GPR group 10 women came from a private hospital and 7 from a health (public) centres. In the control group there were 6 women from the private hospital and 11 from health (public) centres. Inclusion criteria: LBP; nulliparity; low‐risk singleton pregnancy; gestational age between 20 to 25 weeks; aged 18 to 40 years; absence of obstetric or medical illness; absence of pre‐existing spinal pathologies. Differentiation made between LBP and posterior PP at baseline physiotherapy assessment.
Interventions	Intervention group = GPR (N = 17 analysed): Weekly 40‐minute sessions for 8 weeks. Stretching of the muscles of the posterior chain ‐ angle closure coxo‐femoral and abduction of the upper limbs and closing angle coxo‐femoral with adduction of the upper limbs. Control group (N = 17 analysed): usual prenatal care.
Outcomes	GPR group: Intensity of LBP, using VAS (0 to 10) at baseline, before/after each treatment session. Back‐related functional disability, using the RMDQ at baseline, before/after each session. Control group: Intensity of LBP (0 to 10) and RMDQ measured at baseline, at 4 and 8 weeks. Use of pain medication collected for both study groups.
Condition (LBP, PP, LBPP)	LBP.
Notes	Used Google Translate (Google Translate) to translate from Portuguese; verified by single Portuguese researcher. Paper stated that there was no external funding. Data needed for the meta‐analyses appeared to be incorrectly reported in the paper and we re‐analysed.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'randomisation was performed by using a list of random numbers generated by computer.'
Allocation concealment (selection bias)	Unclear risk	No mention in translated version of allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	'these professionals had lagged randomisation, so did not know to which group each woman was allocated' ... however, those who provided the exercise therapy and those who received it would have known to which group they were allocated.
Blinding of outcome assessment (detection bias) All outcomes	High risk	'at the end of the participation on each woman in the study, they conducted a professional full re‐evaluation of LBP' ... however, the women were the ones who reported their symptoms via the VAS and RMDQ.
Incomplete outcome data (attrition bias) effect of intervention	Unclear risk	3 participants are reported as lost to follow‐up; there is no real clarification of their initial group ‐ it could be control group, but the 17 in each group do not seem to take any losses into consideration.
Selective reporting (reporting bias)	Low risk	Data provided for baseline and after intervention outcome measures for pain and disability.
Other bias	High risk	Not similar at baseline for education or age (intervention group was better educated and older), but similar in other prognostic factors; women in control group used more pain medication (87% versus 12% in intervention group); no information provided on compliance, co‐interventions or use of pain medication; the control group was only measured twice after baseline, the intervention group was measured 8 times, but all within the same time‐frame.