Interventions, outcomes and outcome measurement instruments in stillbirth care research: A systematic review to inform the development of a core outcome set

Background A core outcome set could address inconsistent outcome reporting and improve evidence for stillbirth care research, which has been identified as an important research priority. Objectives To identify outcomes and outcome measurement instruments reported by studies evaluating interventions after the diagnosis of a stillbirth. Search strategy Amed, BNI, CINAHL, ClinicalTrials.gov, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, MEDLINE, PsycINFO, and WHO ICTRP from 1998 to August 2021. Selection criteria Randomised and non-randomised comparative or non-comparative studies reporting a stillbirth care intervention. Data collection and analysis Interventions, outcomes reported, definitions and outcome measurement tools were extracted. Main results 40 randomised and 200 non-randomised studies were included. 58 different interventions were reported, labour and birth care (52 studies), hospital bereavement care (28 studies), clinical investigations (116 studies), care in a multiple pregnancy (2 studies), psychosocial support (28 studies) and care in a subsequent pregnancy (14 studies). 391 unique outcomes were reported and organised into 14 outcome domains: labour and birth; postpartum; delivery of care; investigations; multiple pregnancy; mental health; emotional functioning; grief and bereavement; social functioning; relationship; whole person; subsequent pregnancy; subsequent children and siblings and economic. 242 outcome measurement instruments were used, with 0-22 tools per outcome. Conclusions Heterogeneity in outcome reporting, outcome definition and measurement tools in care after stillbirth exists. Considerable research gaps on specific intervention types in stillbirth care were identified. A core outcome set is needed to standardise outcome collection and reporting for stillbirth care research.