The initiation of lactation in women depends on the growth of the glandular tissue of the breast (mammogenesis) and the differentiation of the mammary secretory epithelial cells (lactocytes) during pregnancy (lactogenesis I). After birth, the continuous nourishment of the fetus from the mother via the umbilical cord is replaced by the equally important but intermittent nourishment from the mother's breast. The onset of copious milk production (lactogenesis II) is closely coupled to the factors controlling the birth process. In mothers who have delivered pre-term, mammogenesis and lactogenesis I may be truncated and close consideration must be given to all physiological aspects of this complex process when assisting preterm mothers to establish successful lactation. In Singapore, the problem is not restricted to mothers of preterm babies. In a nation-wide survey by the Health Promotion Board in 2001, inability to produce enough breast milk was stated as the reason for not breastfeeding by 53% of mothers two months after birth.