Table 1.

Summary of measures

Measurement Construct	Description	Scoring
Sociodemographic characteristics
	Age, marital status, cultural background, first language, education, income and housing. Income was defined as pre-tax annual income from all sources of employment including unreported income and excluding any money received from family, friends or income assistance [28].	Descriptives.
Psychological resources
Self-efficacy	General Self-Efficacy Scale [29]. Likert scale 10 items, e.g., “I am certain that I can accomplish my goals.”	Higher scores represent higher levels of self-efficacy.
Mastery	Pearlin Mastery Scale [30]. Likert scale 7 items, e.g., “I have little control over the things that happened to me.”	Higher scores represent higher levels of mastery.
Cognitive ability
	Shipley-II [31]. Vocabulary Subscale 40 items assesses acquired knowledge. Abstraction Subscale 25 items assesses abstract reasoning.	Higher total raw scores indicate better performance.
Executive functioning
Inhibition of interference	Stroop Colour and Word Test [32]. Cognitive assessment of ability to inhibit interference in the reaction time of a task.	Higher raw scores represent better cognitive performance.
Visual attention and task switching	Trail Making Test [33, 34]. Participants were timed while first sequentially connecting numbered circles (1–2, 2–3, etc.; TMT-A), then lettered and numbered circles (1-A, A-2, 2-B, etc.; TMT-B).	Shorter times represent better scores. A ratio of TMT-B / TMT-A represents executive control [35].
Socioeconomic disadvantage
Having low income	Pre-tax annual income from all sources of employment including unreported income and excluding any money received from family, friends or income assistance.	Living on low income at <$20,000 annual employment income.
Having limited education	Not completing the equivalent of a BC high school diploma.	Dichotomous (yes/no) variable.
Being single (having limited social supports)	Not married or common-law (living together consecutively for one year or more).	Dichotomous (yes/no) variable.
Homelessness	Living on the streets or in an emergency or homeless shelter, staying in places not meant as residences, (e.g., car or tent), and/or experiencing “hidden homelessness”, (e.g., staying with someone because of no permanent address or having nowhere else to live or “couch-surfing”) [35, 36].	Dichotomous (yes/no) variable.
Unstable housing	Having to move three or more times or experiencing homelessness (past year).	Dichotomous (yes/no) variable.
History of child maltreatment
Child maltreatment age 16 years or younger	Childhood Trauma Questionnaire – Short Form [37]. Likert scale 28 items, e.g., “When I was growing up, I didn’t have enough to eat.”	Moderate-to-severe levels of any type of abuse or neglect.
Exposure to intimate partner violence
Including physical abuse, emotional abuse and harassment	Composite Abuse Scale [38]. Likert scale 30 items, e.g., “My partner told me that I wasn’t good enough.” Partner was defined as husband/wife, partner or boy/girlfriend for longer than one month.	Higher scores indicate higher levels of abuse.
Mental and physical health
Psychological distress	Kessler Psychological Distress Scale [39]. Likert scale 10 items, e.g., “About how often did you feel hopeless?”	Total scores of > 25 represent moderate-to-severe anxiety or depression.
Mental and physical health conditions	Any long-term health conditions diagnosed by a physician affecting day-to-day activities [40, 41].	Number and type of diagnosed conditions.
Prenatal substance use
Nicotine, alcohol, cannabis, and other street drugs	Frequency of use [42].	Dichotomous (yes/no) variables.
Receipt of health and social services
Health services received for physical concerns	Visiting primary healthcare providers (family doctors, nurse, and midwives) and receiving prenatal classes.	Number and type of services.
Social services received	Income assistance through provincial or federal programs such as: BC Income and Disability Assistance, Canada Disability Benefits and Employment Insurance, BC Hardship Assistance, and BC Youth Agreements.	Number and type of services.