Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Perinatal mortality
Systematic review	28,208 pregnant women, not specifically those with unexplained recurrent miscarriage 20 RCTs in this analysis	Perinatal mortality 2.9% with aspirin 20 mg to 150 mg daily 3.1% with placebo Absolute numbers not reported	RR 0.92 95% CI 0.81 to 1.05		Not significant
Systematic review	Pregnant women (number not reported), not specifically those with unexplained recurrent miscarriage 13 RCTs in this analysis	Perinatal mortality with aspirin up to 75 mg daily with placebo Absolute numbers not reported	RR 0.92 95% CI 0.78 to 1.09		Not significant
Neonatal bleeding
Systematic review	26,058 pregnant women, not specifically those with unexplained recurrent miscarriage 12 RCTs in this analysis	Neonatal bleeding 1.8% with aspirin (any dose) 1.8% with placebo Absolute numbers not reported	RR 1.03 95% CI 0.86 to 1.25		Not significant