The birth of a child requires every family to make significant changes. This transition necessitates a major adaptation often associated with a greater degree of vulnerability which, in turn, can be exacerbated by special circumstances including those rooted in the migration experience. Can multidisciplinary intervention teams take into account this dual reality when they are evaluating integrated health care services during the perinatal period? This study looked at these issues in two stages : first, we investigated the relationship between migratory circumstances and parenting through an exploratory study of immigrant mothers (n = 91) during the perinatal period; then we conducted an exploratory study of multidisciplinary health workers (n = 19) in order to examine implicit aspects of the decision-making process which induce health workers to refer, or not, a mother who is considered vulnerable. This dual and complementary perspective on the vulnerability of immigrant mothers during the perinatal period suggests that a new light be cast on the particular dynamics emanating from the simultaneous experiences of migration and motherhood.