For most authors, it is clear that the early childhood worker needs to build a strong and trusting relationship with the family and use it as a tool for change by modifying negative relationship models or by increasing the family’s trust in care (Korfmacher et al. 2007). Unfortunately, it is often difficult to build a solid working alliance with vulnerable families. Indeed, these “high-risk” families, also known in the literature as “hard-to-reach families,” have frequently suffered painful and sometimes traumatic early experiences, that can result in a difficulty to trust others and maintain stable relationships (Guedeney et al. 1995). Caught up in their relational insecurity, these parents find it more difficult to accept help and support (Dozier et al. 2001). They are often unable to apply for help and are thus rather reluctant to meet a professional. The first contact generally takes place in an atmosphere of deep distrust and fear, in which attachment issues are raised (Guedeney and Guedeney 2007). This challenge is made harder by the fact that some of these families have already faced problems with some institutions, e.g., interchangeable professionals who break their word and are not completely involved (“the bureaucratic Transference” as Seligman wrote, 1984).

For this reason, the practitioner must be fully committed and patient and propose a more flexible approach such as home-based interventions, which represent an interesting health-care strategy.

With regard to families, home visits make evaluation and intervention possible in their own environment, which means a more comfortable situation for both parents and infants. Therefore, evaluation is probably more precise, relying on various natural situations and enabling a better assessment of the family’s situation in terms of its dysfunction, but also its resources. At home, professionals can pay attention to everyday acts and interpersonal relationships. They can better assess the abilities of the child and his family, the risks they are facing, and the ways in which they might be helpful to them.

Home visits allow professionals to have a global approach to families, particularly by assessing the multiplicity of risks present. For example, professionals have to deal with the social difficulties of families, sometimes before giving any other kind of support. Indeed, such social difficulties are often a crucial factor in their psychological and affective distress. Professionals need to take this into account and think about what kind of help they might provide for it. According to D. Weatherston (2000): “parents cannot adequately meet their infant’s basic needs until their own basic needs are met.”

PMI home visits are performed by nurses, who have been increasingly concerned by the rising number of children being referred for mental health problems. Exposed to the major difficulties and psychological distress of these families, for which they usually have not been trained, these professionals frequently find themselves isolated. Psychological support is one of the missions of the PMI centers, but it remains a difficult and potentially destabilizing practice for nurses. These kinds of situations therefore require the support of all health-care professionals, particularly the PMI psychologists, but also the psychiatric care services.

In other countries where there is no preventive system similar to the PMI, many home visit research programs have been developed. They mostly focus on the identification of risk factors (or vulnerability factors) and are based on well-defined protocols. One of the major early home visit research programs has been conducted by David Olds and collaborators since the 1970s. It is based on early (during the pregnancy), extended (for months or even years after birth), and ongoing home visits. They focus on vulnerable women and target factors amenable to change (parenting skills, health education, professional training, social assistance, integration into health-care, education, and social systems). Home visits are performed by trained and supervised nurses (Olds and Korfmacher 1998; Olds et al. 2004; Olds 2006).

Many other programs have been developed over the past 20 years (McDonough 1993; Weatherston 2003; Guedeney et al. 2013) with variable methods and results. However, existing programs have shown they can have a considerable positive impact on the child’s developmental trajectory. The pioneering study of Olds at Elmira (2004, 2006) showed that such visits may reduce the risk of maternal and infant morbidity and improve the quality of parent-child relationships, with a clear impact on the child’s development (better cognitive and socio-emotional outcomes, fewer externalized behavioral symptoms in infants under the age of 2 years, in particular). Applebaum’s meta-analysis (2004) also highlighted positive results on outcome measures such as better use of contraception, longer intervals between pregnancies, and less attendance in emergency rooms for infants and toddlers. However, few prevention programs have demonstrated convincing results with regard to preventing postnatal depression (Dugravier et al. 2013). In addition, it appears that maternal depression and insecure attachment may moderate the impact of preventive home visits (Duggan et al. 2009). Indeed, researchers have emphasized that the mental representation of mothers about their early attachment relationships is correlated with their emotional engagement in intervention (Korfmacher 2002). There is also evidence that effects may be less visible in the highest-risk families where too many risk factors accumulate.