Pregnancy and early childhood are critical periods. Maternal and Child Health (PMI) services provide free access to support and preventive care for mothers and children. For example, in the area of perinatal care, the PMI service in Paris has regularly adapted its operations to ensure that expectant mothers facing psychosocial vulnerabilities have the most equitable access possible. While waiving fees removes the financial barrier, it is equally important to consider available human resources and the organization of the care pathway to ensure equal access to prenatal care for all women.