Variable | Measurement | Source | Assessment timing |
---|---|---|---|
Intervention receipt/dose | Number of AME study visits and home-AME sessions | Investigator study tracking system, SMS queries | Daily from 37 wk. visit to birth |
Antenatal milk volume | Total volume of antenatal milk expressed during study and average volume per AME session, in milliliters | SMS queries | Daily/weekly from 37 wks to birth |
Demographic characteristics | Age, race, ethnicity, gender, Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), education, employment, relationship status, size of household | IFPS-II adapted and investigator-created items | Enrollment |
Breastfeeding attitudes and intentions/plans | Sum scale score measuring extent of agreement with statements about breastfeeding attitudes on Likert scale; sum scale score measuring extent of agreement with statements about breastfeeding duration and exclusivity on Likert scale; anticipated infant age of formula/ other foods introduction and stopping breast milk feeds | Iowa Infant Feeding Attitude Scale (13 items) [57]; Infant Feeding Intentions Scale (3 items)a [58]; IFPS-II adapted items | Enrollment |
Prior breastfeeding exposures, inter-generational effects | Whether participant and partner were breastfed (yes/no), proportion of friends/relatives that breastfed, perceived importance of others’ feeding opinions on Likert-scale | IFPS-II adapted items | Enrollment |
Birth characteristics and birth center course | Birth mode, anesthesia, neonatal intensive care unit admission, infant birthweight, length of birth center admittance | Birth center EHR abstraction | Birth center admittance |
Participant and infant health status | Various chronic, pregnancy, birth associated morbidities checklist | Prenatal and birth center EHR abstraction, investigator-created survey items | Enrollment and birth center admittance |
Participant weight | Pre-pregnancy body mass index, gestational weight gain | Prenatal and birth center EHR abstraction | Enrollment and birth center admittance |
Anxiety and depression | Frequency of feelings or thoughts | Perceived Stress Scale (4 items) [59]; PRAMS anxiety-depression (3 items) [60] | Enrollment, PP wks 2, 6, 12; 6 & 12 mos |
Breastfeeding practices in birth center and home and milk expression details | Timing of first direct breastfeed, average LATCH score at birth center [61], number of lactation consults, number of direct breastfeeds and expressed milk feeds 24 hours prior to birth center discharge; mode of own milk feeds, frequency and methods used to express and feed one’s own milk | Birth center EHR abstraction, IFPS-II adapted and investigator-created items | Birth center admittance and PP wks 2, 6, 12; 6 & 12 mos |
Breastfeeding support and education | Checklist of support from various resources, workplace breastfeeding support checklist, extent of agreement about support quality | IFPS-II adapted and investigator-created items, Breastfeeding Friendly Worksites Scorecard adapted items [62] | Enrollment, PP wks 2, 6, 12 |
Breastfeeding problems | Checklists of breastfeeding problems, reasons for formula use, reasons for breastfeeding cessation | IFPS-II adapted items | PP wks 2, 6, 12; 6 & 12 mos |
Breastfeeding satisfaction | Extent of agreement with statements about breastfeeding | MIBSS subscale of H&H Lactation Scale (5 items) [33] | PP wks 2, 6, 12 |
Embodied weight stigma | Subscale score of instrument assessing frequency of body image psychological discomfort, shame | Weight- and Body-Related Shame and Guilt Scale (WEB–SG), Shame subscale (6 items) [63] | Enrollment |
Traumatic birth experiences | Sum scale of Likert-scale instrument assessing stress, fear, and partner support surrounding birth | Birth Experiences Questionnaire (10 items) [64] | 2 wk |
Racial discrimination | Sum scale of instrument assessing frequency of perceived racial discrimination experiences | Everyday Discrimination Scale (9-item) [65] | Enrollment |