Low rates of lactation and high rates of postpartum depression contribute to perinatal mortality and morbidity and Black birthing parents and infants are at the highest risk. Yet most interventions to support lactation and postpartum mental health are based on models of care that are unrepresentative of Black and global majority communities. The principal investigator's (PI) previous Randomized Controlled Trial (RCT) using soft infant carriers was effective in increasing lactation and decreasing postpartum depression in a sample of Latinx postpartum parents.

Black infants are half as likely as white infants to be breastfed at 3 and 6 months, and 12 months. Black parents also experience an increased risk of perinatal mental health challenges like postpartum depression yet are less likely to initiate and/or follow up with mental health treatment due to societal stigma on mental health and lack of access to financial resources, amongst other reasons. Low lactation rates are associated with immediate threats to infant and parental health, including increased risk of infection, asthma risk, and diarrhea. Longer-term health impacts are suboptimal brain development, decreased academic and cognitive performance, an increased risk of childhood obesity, and an increased risk of breast and ovarian cancer and diabetes in the parent. Supporting lactation and mental health in the postpartum period provides an opportunity for immediate, long-term, and intergenerational impact. Yet most interventions to support lactation and mental health are based on cultural models of care that are unrepresentative of the postpartum practices of Black and global majority communities. They can also be costly and add burdens to both parents and the professionals supporting intervention implementation.

This study employs carrying as an intervention that is culturally rooted, cost-effective, and does not add burdens. Keeping a baby strapped to a caregiver's body with a textile-based device, known as "babywearing," "backing," or simply "infant carrying," is a practice that has likely existed since the beginning of human history. Among the global majority, infant carrying and sustained parent-infant contact is not only culturally and historically ubiquitous but is also very well understood for its benefits. International fieldwork (Guatemala and Congo) by the PI and others document the ubiquity of parent-infant physical contact. This cultural variation in mother-infant physical contact is reflected in patterns of breastfeeding behavior, such that in communities where infants are in more physical contact with caregivers they are breastfed for longer, a pattern that has been documented both across cultures (e.g., between parents in Washington DC and Central African Republic) and within cultures (two groups of parents in London). Only a handful of studies have tested whether this cultural practice of infant carrying is contributing to lactation outcomes. An RCT published by the PI demonstrated that an infant carrier intervention increased lactation rates in a low-income Latina population. Using a randomized two-arm, parallel-group trial conducted in collaboration with a home-visiting program in a low-income, urban, and primarily Latinx community, 50 parents were randomly assigned to receive an ergonomic infant carrier and instruction on proper use to facilitate increased physical contact with infants (intervention group), and 50 parents were assigned to a waitlist control group. Parents in the intervention group were more likely to be breastfeeding or feeding expressed human milk at 6 months (68%) than control group parents (40%; P = .02). Another study in Italy showed that an intervention with infant carriers to increase mother-infant physical contact increased the likelihood of continued breastfeeding, and two US-based studies demonstrated increased attachment between parent and infant after an intervention with infant carriers. These effects of infant carrying in the months after birth align with the decades of evidence from RCTs in hospital and NICU settings demonstrating that skin-to-skin contact immediately after birth has both immediate and long-term benefits after preterm birth, including increased lactation and decreased postpartum depression. Though effectiveness has now been demonstrated in some communities, no research thus far has tested the effectiveness of infant carrying interventions among Black parents in the US, who are experiencing the most inequities in lactation and postpartum mental health. Furthermore, no research has assessed strategies for effectively implementing this intervention in scalable, community-based settings.