Objective We assessed whether maternal mental health problems increased rates for child injury during the preschool years and mid-childhood, and the extent to which associations could be accounted for by a range of potential explanatory factors.

Design We analysed the UK Millennium Cohort Study, a nationally representative sample with data collected throughout childhood. Multinomial regression was used to investigate whether two measures of maternal mental health (diagnosed depression/anxiety and psychological distress) were associated with subsequent childhood injury. Models adjusted for sociodemographics, parenting and child externalising behaviours.

Main outcome measure Maternal report of unintentional injuries (none, 1, 2+) recorded at three data collection periods (3–5 years; 5–7 years; 7–11 years).

Results The analytic sample comprised n=9240 families who participated 3–11 years with complete data on exposures and outcomes (multiply imputing missing covariates). Exposure to maternal mental health problems was associated with increased rates of subsequent childhood injuries. Associations attenuated after adjustment for potential explanatory factors, although they remained elevated. For example, high maternal distress was associated with injuries 3–5 years (adjusted relative risk ratio (aRRR): 1 injury=1.18, 95% CI 0.86 to 1.61; 2+ injuries=2.22, 95% CI 1.22 to 4.02); injuries 5–7 years (aRRR: 1 injury=1.31, 95% CI 0.97 to 1.76; 2+ injuries=1.84, 95% CI 1.09 to 3.09); and injuries 7–11 years (aRRR: 1 injury=1.03, 95% CI 0.81 to 1.31; 2+ injuries=1.33, 95% CI 0.97 to 1.81).

Conclusions Children exposed to mothers with mental health problems had higher rates of childhood injury than those not exposed. If further investigation of this association suggests causality then it will be important to test measures that address mothers’ mental health issues with a view to reducing injuries among their children.