It is clear that breastfeeding is always the preferred option – research clearly points to it having a wide range of benefits for infants, from promoting stronger immune systems to cognitive development and longer-term health. But the ugly truth is that it does not always work. Some people"s bodies don"t make enough milk to sustain a child. Some babies are born unable to latch correctly onto the breast. Some women"s nipples are, in rare cases, not a good match for their babies" mouths – in a tragic episode recorded in the diary of Samuel Pepys, the great diarist of 1660s London, he describes a new mother as having no nipples, perhaps a way of describing what today are called inverted nipples, which can make breastfeeding more difficult. Her baby soon died.