Slow Weight Gain Following Early Good Weight Gain

by Jack Newman, MD, FRCPC

Introduction:
Sometimes, babies who were doing very well and gaining weight very well with exclusive breastfeeding start to gain more slowly and even not at all after two to four months. Exclusively breastfed babies do tend to gain more slowly after three or four months compared to artificially (formula) fed babies but this is normal.

The more rapid weight gain of the artificially fed baby is not the standard. Breastfeeding is the normal, natural, physiologic way of feeding infants and young children. Using the artificially fed baby as the model of normal is not rational and leads us to make errors in advising mothers about feeding and growth.

In some cases, however, an illness in the baby may result in slower than expected weight gain. Supplementing with formula does not cure the illness and may rob the baby of the beneficial effects of exclusive breastfeeding.

You can tell when a baby is getting milk and when he is not (see below and the video clips at the website nbci.ca). If the baby is sucking at the breast and not getting milk, well, this explains why he is not gaining weight and it is most likely the mother's milk supply is down. The mother's milk having decreased is the most common reason that the baby fusses and pulls at the breast and/or no longer gains weight well enough.

Why would your milk decrease?

1. You have gone on the birth control pill, the Mirena IUD, have received Depo Provera or are taking estrogens and/or progesterones in another way. It should be noted that breastfeeding itself has a significant contraceptive effect, especially if you are breastfeeding exclusively.

2. You are pregnant. Pregnancy definitely decreases the milk supply.

3. You have been trying to stretch out the feedings or "train" the baby to sleep through the night. If this is the case, feed the baby when he is hungry or sucking his hand. Consider safe co-sleeping so the baby feeds at night and you don't have to get up to feed him.

4. You are using bottles more than occasionally. It is better to avoid bottles altogether, but the occasional bottle is not usually going to influence your milk supply. However, regular, frequent bottle use results in the baby latching on less well and thus getting milk less well from the breast. Often the baby will pull off before he has "emptied" the breast, and the milk supply decreases. See below under "This reason requires more explanation".

If you must have the baby fed by someone other than you, then a cup (not a sippy cup as that is the same as a bottle) would be better than a bottle. See video at nbci.ca.

5. An emotional shock can, occasionally, decrease the milk supply.

6. Sometimes an illness in the mother, particularly if the illness is associated with fever, can decrease the milk supply. Mastitis and blocked ducts can also decrease milk supply. Fortunately this doesn't happen most of the time.

7. Could you be doing too much? It is easy to get caught up in trying to conform to others' ideas of what you should be doing. Let the housework go. Sleep when your baby sleeps. If you are tired, lie down with the baby to breastfeed and let yourself fall asleep. Make sure co-sleeping is done safely according to the guidelines set out by UNICEF and UK Baby Friendly.

8. Some drugs may decrease your milk supply. It is possible antihistamines do, especially the older ones such as Benadryl; pseudoephedrine (Sudafed) can also decrease the milk supply. Note that these two drugs (or similar ones) are found in cold and allergy medicines.

9. You are feeding one side only at each feeding. It is not a good idea to feed the baby on just one side, to follow a rule. Yes, making sure the baby "finishes" the first side before offering the second can help treat poor weight gain or colic in the baby, but rules and breastfeeding do not go together well. If the baby is not drinking, actually getting milk, there is no point in just keeping the baby sucking without getting any milk for long periods of time. You should "finish" one side and if the baby wants more, offer the other.