Bergstrom 2009.

Methods	Randomised trial
Participants	Sweden Inclusion criteria: Nulliparous, Swedish‐speaking and attending any of the participating clinics. No specific inclusion criteria were defined for the women's partners
Interventions	Intervention: antenatal education focusing on natural childbirth preparation with training in breathing and relaxation techniques (psychoprophylaxis) Control: standard antenatal education focusing on both childbirth and parenthood, without psychoprophylactic training Both groups: four 2‐hour sessions in groups of 12 participants during third trimester of pregnancy and one follow‐up after delivery
Outcomes	Mode of delivery, epidural analgesia, experience of childbirth, and parental stress in early parenthood
Notes	Baseline (Control group) CS rate: 21% Date of study: October 2005 to February 2007 Funding: Swedish Research Council and Karolinska Institute Conflicts of interest: the authors declare that they have no known conflict of interests.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"The randomisation was conducted by the computerised algorithm with two priorities: Stratification by (1) equal number of participants per model in all clinics taken together and (2) balancing the numbers of each model within the respective clinic."
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided in the report
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information provided in the report
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Main outcomes (modes of delivery) objective
Baseline characteristics similar?	Low risk	Baseline characteristics in study groups similar (Table 1 in the article)
Baseline outcome measurements similar?	Unclear risk	Baseline measures of main outcomes not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Numbers lost to follow‐up (Figure 1 in the article) unlikely to bias effect estimates
Selective reporting (reporting bias)	Low risk	Prespecified outcomes reported
Protected against contamination?	High risk	Some women in standard care also got psychoprophylaxis education at home
Other bias	High risk	Unit of analysis issues: “We have analysed data of individuals in spite of the fact that exposures was given to groups of individuals.”