Background Standardising outcome collection and reporting in pre‐eclampsia trials requires an appraisal of current outcome reporting. Objectives To map maternal and offspring outcome reporting across randomised trials evaluating therapeutic interventions for pre‐eclampsia. Search strategy Randomised trials were identified by searching bibliographical databases from inception to January 2016. Selection criteria Randomised controlled trials. Data collection and analysis We systematically extracted and categorised outcome reporting. Main results Seventy‐nine randomised trials, reporting data from 31 615 maternal participants and 28 172 of their offspring, were included. Fifty‐five different interventions were evaluated. Included trials reported 119 different outcomes, including 72 maternal outcomes and 47 offspring outcomes. Maternal outcomes were inconsistently reported across included trials; for example, 11 trials (14%) reported maternal mortality, reporting data from 12 422 participants, and 16 trials (20%) reported cardiovascular morbidity, reporting data from 14 963 maternal participants. Forty‐three trials (54%) reported fetal outcomes and 23 trials (29%) reported neonatal outcomes. Twenty‐eight trials (35%) reported offspring mortality. There was poor reporting of childhood outcomes: six trials (8%) reported neurodevelopmental outcomes. Less than half of included trials reported any relevant information regarding harms for maternal participants and their offspring. Conclusions Most randomised trials evaluating interventions for pre‐eclampsia are missing information on clinically important outcomes, and in particular have neglected to evaluate efficacy and safety in the offspring of participants. Developing and implementing a minimum data set, known as a core outcome set, in future pre‐eclampsia trials could help to address these issues. Tweetable abstract Future #preeclampsia research requires a core outcome set to reduce #research waste. https://twitter.com/coreoutcomes https://twitter.com/jamesmnduffy International Prospective Register of Systematic Reviews: CRD42015015529; http://www.crd.york.ac.uk/PROSPERO/display_record.aspID=CRD42015015529.

In randomized trials evaluating interventions for pre-eclampsia, critical information related to the primary outcome, including definition and measurement, is regularly omitted. Developing a core outcome set for pre-eclampsia trials would help to inform primary outcome selection and outcome measure reporting.

This study has provided a snapshot of the pattern of drug use in the gay community which compliments findings of the self-reported surveys and other studies from the same population. The information obtained will be helpful in guiding in designing harm reduction interventions in this community and for monitoring the impact of changes in legislation.