Many low income mothers are suffering from mental stress that can harm their children, according to a new study.
Nearly 30% of the women surveyed reporting not always having enough nappies to change their children as frequently as they wanted to.
Data collected for the study found that the stress of not being able to afford a sufficient supply of nappies was an even stronger predictor of mental health than food insecurity.
The study was conducted by a team of researchers in the US by New Haven Mental Health Outreach and included 877 low-income women.
Researcher Joanne Goldblum, of the National Diaper Bank Network, which supports nappy banks, said: "A mother's number-one priority is meeting her children's basic needs. Diapers are a basic need, akin to food and housing. But unlike those other things, there are no public programmes parents can turn to for help."
Women who reported needing nappies also found it more difficult to manage stress, depression and trauma, according to the study published in the Pediatrics journal.
Hispanic mothers and grandmothers raising children were more likely to experience difficulty keeping a sufficient supply of nappies.
Researcher Dr Megan Smith, Assistant Professor at the Yale School of Medicine, warned that parental stress and depression could negatively impact children.
"Many women who had trouble obtaining diapers also reported significant mental distress. Health care providers should recognise diapering difficulties as a serious issue and possibly an indicator of mental health need."
Study co-author Dr Alison Weir said: "We knew that diaper need harms babies, who are prone to rashes or more serious infections when not changed frequently enough.
"Our research raises concerns about the long-term impact. When parents have high levels of stress or depression, children are at greater risk for social, emotional and behavioural problems. That has far-reaching effects on a child's development and success in school."