Feinberg 2015.

Methods	Randomised trial
Participants	USA Pregnant women and their partner (couples were aged 18 and above, living together, and expecting a first child at recruitment) The analytic sample consisted of 147 mothers (71 from control, and 76 from the intervention group) who completed interviews when children were 6 months old (wave 2), interviewed from 2004 to 2006
Interventions	Intervention: psychosocial couple‐based prevention programme Control: routine care (no educational classes)
Outcomes	Delivery mode, complications of pregnancy and delivery, mother and newborn length of hospital stay
Notes	Baseline (control group) CS rate: 40% Date of study: “The analytic sample consisted of 147 mothers (71 from control, and 76 from the intervention group) who completed interviews when children were 6 months old (wave 2), interviewed from 2004 to 2006.” Funding: National Institute of Child Health and Development (K23 HD042575) and the National Institute of Mental Health (R21 MH064125‐01). Conflict of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information provided
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information provided
Baseline characteristics similar?	Low risk	In page 4 in the article: "To assess randomization, we performed attrition analysis and baseline equivalence testing by intervention condition. Results showed baseline equivalence across a wide array of pretest"
Baseline outcome measurements similar?	Unclear risk	Insufficient information provided
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information provided
Selective reporting (reporting bias)	Low risk	All relevant outcomes in the methods section are reported in the results section
Protected against contamination?	Unclear risk	Insufficient information available to assess likelihood of contamination
Other bias	Low risk	No evidence of other bias