Protecting an unborn baby from abuse and neglect presents particular challenges for professionals due to the uncertainties about appraising future harm and functioning of family relationships. This systematic narrative review synthesises studies of professional decision making by health and social care professionals regarding child protection of an unborn baby. Five bibliographic databases (ASSIA, CINAHL Plus, Ovid MEDLINE, PsycINFO, Social Care Online) were searched using an explicit and robust search; papers identified as relevant were appraised for quality and combined using a narrative synthesis based on the main themes in the papers. Ten papers met the inclusion criteria, including qualitative studies, surveys and randomised trials of the effectiveness of decision support tools. The papers identified the following case risk factors relating to risks to an unborn baby: alcohol abuse; ante-natal care; previous children in care; domestic violence; drug abuse; lack of education; employment issues; unrealistic expectations of the baby; housing issues; learning disability; feelings about pregnancy; low socio-economic status; mental illness; mother's childhood experiences; lack of parenting capacity; physical disability. There were several papers on developing risk assessment tools. A few papers focused on risk assessment and decision processes including engagement with pregnant women. There was some discussion of psychosocial supports for risks in pregnancy. There is useful published material on the range of risk factors, and more limited material on the development of assessment tools and on decision processes. The psychosocial supports that might be provided to the pregnant woman as decision options is an area for future research.