A breastfed baby takes small but increasing amounts of milk over the first few days . At four days of age, most breastfed babies are taking about an ounce and a half at each feeding, and by five days two and a half ounces or more. Of course, when you're nursing, it's impossible to know the precise amount of milk that your baby gets at each feeding. The most reassuring signs of adequate intake in the early days include the passing of meconium and transitional stools.
Babies urinate very little in the first few days.
Your milk production should begin by 72 hours postpartum starting with a noticeable change in your breast fullness. Hearing your baby swallow and feeling your breasts soften during feedings are reassuring signs. By his fifth day of life, your baby should be having yellow or mustard-colored stools and wet diapers every few hours. Babies normally shed ounces in the first few days of life, but weight loss should be no more than 10 percent of the baby's birth weight. By five days of age, a baby begins gaining weight, at least an ounce a day.