Many babies will get frustrated when you put them to the breast initially and little or no milk is coming out, so they won't stay on for long. Using a supplemental feeding system can solve this problem by ensuring that the baby's sucking efforts are rewarded.(SNS by Medela, or Lact-Aid). (I carry the SNS if you can't find it in your area -- the price is $35.00 plus $3.50 shipping). These tube-feeding devices allow you to deliver formula while the baby is nursing at the breast, and your breasts receive stimulation at the same time. Most babies will accept the supplemental feeding systems because they are receiving a steady flow of milk with each suck, much as they would with a bottle. As your milk supply increases, the amount of supplement will level off while your baby continues to gain weight. This means that your supply is filling the gap, and you can gradually reduce the amount of supplement offered. In the meantime, your baby is feeding at the breast and you can enjoy the physical closeness of the nursing relationship, regardless of the amount of breastmilk that he is receiving.
Inducing lactation, which is the process involved in nursing an adopted baby, is more challenging than relactating. You will find that there is a lot of contradictory information out there about inducing lactation. I think that's because there are no exact answers about a "right" or "wrong" way to do it. Relatively few mothers have tried adoptive nursing (many people are surprised to know it's even possible) although the numbers are increasing as the many nutritional and emotional benefits of breastfeeding become more well known. What works for one adoptive mother may not work for another, so a lot of the research has been on a trial and error basis.
Breastmilk production is a function of the pituitary gland. When your breasts receive stimulation, either from the baby or a pump, signals are sent to the pituitary gland to start producing prolaction (the hormone that makes the milk) and oxytocin (the hormone that releases the milk). During pregnancy, breast changes occur over a period of 4-5 months. These changes are, of course, not present in the adoptive mother. Sucking stimulation can cause these changes to occur over a much shorter period of time, but the supply builds very slowly. Because your body doesn't have the benefit of these hormonal changes during pregnancy, much more sucking stimulation is needed to induce lactation than it takes to establish lactation after giving birth. Previous breastfeeding experience (or lack of it) is not a major factor in inducing lactation.
It is important to have realistic expectations. An adoptive mother may or may not ever produce a full milk supply. Most women will produce some milk, some produce a full supply relatively quickly, and some never produce milk at all. The majority of adoptive mothers will not produce enough breastmilk to adequately nourish their baby without supplements. How much you produce depends on many factors, such as the baby (his age, sucking needs, previous feeding experience, and temperament; how frequently and effectively you stimulate your breasts (type of pump used, baby's willingness to suckle, how often you are able to find time to pump/nurse, etc.); your individual response to stimulation, since each mother's body chemistry is unique; and how long you have been nursing or pumping (some mother's supplies build slowly, then level off; some keep increasing for many months or years).
Since nursing involves so much more than just transferring milk from breast to baby, many adoptive mothers find that the act of nursing, with the physical and emotional closeness it brings, is just as important as the amount of milk the baby actually receives. Even if you produce only small amounts of breastmilk, your baby will get significant benefits from both the milk itself and the security and warmth of nursing at the breast.
The following is what I recommend for the mother who has 6 months or more to prepare for her baby's arrival (this plan can be modified for mothers who have less time to prepare):