Parenting and childcare responsibilities, harm reduction service engagement, and opioid overdose among women and men who use illicit opioids in New York City

•The majority of people who use illicit opioids have children.•Women who used illicit opioids were more likely to report living with children and avoiding substance use treatment for fear of child welfare involvement.•Drug use-related stigma was linked to higher prevalence of avoiding treatment for fear of child welfare among parents.•For mothers, those living with children were less likely to have been trained to use naloxone, and those who avoided treatment for fear of child welfare were more likely to not carry naloxone.•Among both mothers and fathers, having difficulty accessing harm reduction services due to childcare was associated with lifetime opioid overdose.