
A few days
In the first days of breastfeeding, a mother releases colostrum. Colostrum is a thick milk that often has a yellow color. Sometimes it is referred to as "liquid gold" because of the color and its value to your baby. Mom makes only a small amount of colostrum, so it's important for baby to drink all that he can.
When your baby drinks the antibodies contained in colostrum, it is like giving him his first immunization! Colostrum is also high in protein, which is perfect for newborns, and helps him pass the dark, sticky stools (called meconium) he has in the first day or two.
Nurse your baby often in the first few days so that he'll get plenty of colostrum, and so that you'll build a strong milk supply.

2 Weeks
The protein in breastmilk is much easier to digest than the protein in formula. This makes your baby less likely to have digestive problems, such as gassiness, rashes, and colic.

4 to 6 Weeks
Breastfed babies are healthier and get sick less often. Formula-fed babies are much more likely than breastfed babies to be sick during the first 2 months of life.

3 to 4 Months
Babies who are breastfed have a 36% lower risk of SIDS (Sudden Infant Death Syndrome) which peaks at 2-4 months of age.
Your baby's immunities are lowest between 2 to 6 months of age. By breastfeeding, you are providing him the best protection during this vulnerable time. If you get a cold, it is especially important to keep giving your baby breastmilk. Antibodies and anti-viruses that your body makes to protect yourself will get passed through your milk to help protect him too.

6 Months
When you nurse for 6 months, your baby will have fewer ear infections and will be much less likely to have problems with diarrhea and respiratory infections. It even helps the immunizations he gets at the doctor's office work better.
Babies who are breastfed for at least 6 months have a lower risk of getting childhood cancer.

9 Months
Studies show that children who breastfeed have higher IQs and do better in school. Breastmilk helps with brain development in ways that formula cannot. One study found that 7- and 8-year-old children who were fed breastmilk for at least 9 months had an IQ that was 10 points higher than their formula-fed peers.

1 Year
Breastfeeding helps baby form healthy face muscles and structure. This can help prevent the need for speech therapy or orthodontia when they get older.

More than a year
If your baby nurses for more than a year, you will continue to provide him with nutritious and protective milk. Remember, with each exposure you have to germs, colds, and allergens, you continue to pass along the anti-allergens, antibodies, and anti-viruses he needs to keep him strong.