Cochrane Oral Health's Trials Register, Cochrane Pregnancy and Childbirth's Trials Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO, the US National Institutes of Health Ongoing Trials Register, and WHO International Clinical Trials Registry Platform. Randomized controlled trials (RCTs) and cluster-RCTs assessing the effects of interventions targeted at pregnant women, new mothers or other primary caregivers for preventing early childhood caries (ECC) in infants during the first year of life. Selection of studies, data extraction and management, and assessment of risk of bias in the included studies were independently performed by two authors. Twenty-three trials met the inclusion criteria. Child diet and feeding practices advice could reduce the risk of developing dental caries in primary teeth by 15% with the evidence being of moderate certainty. All other measures showed little to no difference compared to standard care, with evidence of low to very low certainty. Generally, the evidence assessing the effects of interventions targeted at pregnant women and new mother for preventing early childhood caries (ECC) in infants during the first year of life is of low to very low certainty. More robust RCTs are needed to inform practice and policy making.