The rules for a nursing mother or a wet-nurse should be regularity of life, freedom from anxiety, worry, or excitement, a generous diet of easily digested and simply prepared foods, and abundant, gentle, but not excessive exercise. During the first few days after childbirth only liquid foods, such as milk, weak tea, broth, and gruel should be given. After the first three or four days soft foods of various kinds may be eaten. At the end of ten days two meals of the most digestible solid food are allowable. Gradually the mother may return to a normal diet. Liquids, either liquid food or water, should be taken generously, at first to encourage lactation and later to maintain it. No advantage is derived from the excessive use of tea, beer, or other beverages; on the contrary, the mother's digestion is deranged by them and harm is done. During the first weeks of lactation there is more danger of over-feeding a mother than of underfeeding her. So soon as she can, she should be encouraged to sit up, to walk, and to take other gentle exercise proportioned to her strength. To furnish suitable food to her child, a mother must be willing to modify her life so as to meet the requirements of good lactation.

Rotch says that "mothers who are unhappy, who are unwilling to nurse their infants, who are hurried in the details of their life, who are irregular in their periods of rest and in their eating and exercise, are unfit to act as the source of food-supply to their infants." Mothers suffering from chronic diseases or from maladies that are communicable to their offspring should not nurse them. It often happens that mothers who would gladly suckle their children have no milk at all or only a little during the first few weeks after childbirth. For all these reasons, and sometimes because of a mother's death, certain infants cannot have their natural food. Under these circumstances a wet-nurse, if a good one can be had, is to be preferred. She should have a baby of approximately the same age as the one which she is to nurse. She should be perfectly healthy, strong, and even-tempered. Especially should no suspicion of tuberculosis, syphilis, or other communicable disease attach to her. She should be willing so to eat, to exercise, and to live as to fit her best for the care of the infant. Unfortunately, as the parents are so completely dependent upon a wet-nurse for their child's welfare, she is likely to become tyrannical, lazy, and shiftless and thereby unfits herself for her duties. Because of the danger of transmitting hidden disease to a nursling and because of the frequent annoyance arising from the temper and habits of many wet-nurses, and sometimes out of compassion for the child that would be displaced at the mother's breast, parents often prefer to take the somewhat greater risk of rearing their offspring upon substitutes for human milk.