Background Patient decision aids (PDAs) can be used to support pregnant women engaging in shared decisions but little is known about their effects in obstetrics. We aimed to evaluate the effects of PDAs designed for pregnant women on clinical and psychosocial outcomes.

Search strategy Electronic searches were performed using Medline, Embase, the Cochrane Library and Medion databases from inception to January 2011. Reference lists were also examined and key experts contacted.

Selection criteria Eligibility criteria included randomised controlled trials which reported on PDAs for women facing any treatment decision in pregnancy published in English. Studies evaluating health education material which did not address women's values and preferences were excluded.

Data collection and analysis Data on all outcomes were extracted and summarised. All studies were critically appraised for potential sources of bias and, when possible to obtain, the reported PDAs were evaluated. Meta-analysis was not possible due to heterogeneity in outcomes used in the primary research.

Main results PDAs have been developed for decisions about prenatal testing, vaginal birth after caesarean section and external cephalic version. Use of PDAs is associated with a number of positive effects including reduced anxiety, lower decisional conflict, improved knowledge, improved satisfaction and increased perception of having made an informed choice.

Conclusions PDAs have the potential to improve obstetric care. However, currently the evidence-base is limited by the small number of studies, the quality of the studies and because they involved heterogeneous PDAs, patient groups and outcomes.