Breast Milk



While preparing for a new baby there are many decisions to make about pregnancy, delivery, and about parenthood. Most importantly, you need to decide how you would like to feed your baby. The American Academy of Pediatrics recommends breastfeeding as the sole source of nutrition until 6 months of age. We support the AAPs recommendation for mothers who are able and desire to breastfeed their baby. Breast milk is an amazing substance. It provides nutrition as well as other amazing substances that help your baby grown and thrive.


Liquid Gold

Breast milk is an amazing food. It is made up of carbohydrates, fats, and proteins that help your baby grown and develop. It is 88% water so in addition to being nutritious it is also hydrating. And most importantly, breast milk contains immune factors, enzymes, and hormones. Breast milk is made of 200 different components!


Breast milk contains lactose, glucose, fructose, and 130 oligosaccharides (sugars that help feed healthy gut bacteria)


There are two type of protein in breast milk., whey and casein. Early milk has 90% whey and 10% casein, but mature milk has 60% whey and 40% casein. These proteins break down in to 20 different protein components called amino acids. Taurine, one amino acid, helps with brain and eye development. A mother with a premature baby will have more protein, especially whey protein


Half of the energy your baby gets from breastmilk comes from fats including cholesterol. Cholesterol helps make hormones, helps brain development and helps keep your heart healthy. It also includes DHA which is an important fat in development of vision and the brain.

Immune Boosters

Breast milk is an infection fighting super food! It contains as many white blood cells (infection fighting cells) as your own blood. It also contains secretory IgA. These are antibodies that your body makes to protect your baby from illness. This IgA is specially made so that it will not be broken down by digestion in your stomach. Your body also makes b-cell antibodies in response to the germs around you and these antibodies are then passed to your baby through your breast milk. Your breast milk even has tumor fighting cells!


The main antibody in your breast milk is IgA. This IgA helps protect your baby against infection until your baby can make their own IgA. Your IgA antibodies are specific to the germs around you. Your breast milk also contains IgE, IgG, IgM, and IgD. These antibodies help fight off infection and protect against allergies.


Breast milk contains many important hormones. We are still learning how many of them help your baby. Below are 9 hormones and their function:

Prolactin helps make breast milk. It gives you a peaceful feeling and promotes nurturing and caring for your baby. 

Oxytocin is the love hormone. When you secrete Oxytocin, it helps you bond with your baby. It also makes you feel thirsty so that you drink more water!

Thyroid hormones help with the intestines develop.

Epidermal growth factor stimulates growth in the digestive system. Levels are much higher in premature babies.

Beta-endorphins are natural pain relievers that help a baby through birth and adjusting to life outside the womb.

EPO stimulates your baby’s body to make Red Blood Cells.

Leptin helps prevent obesity in babies.

Cortisol may help infants with fluid in the digestive tract, help the pancreas grow and help with stress.

Melatonin, a hormone that helps you sleep, is present in breast milk and helps your baby develop proper sleep patterns. 


Breast milk changes constantly. Every feed is different in nutritional content, hormones, and immunity boosters! It also changes composition based on your baby’s age and needs.

At birth, your first breast milk is called colostrum. This gold fluid contains high concentrations of immune factors and easy to digest protein. This milk helps fight infection as well as encourage healthy bacteria in your baby’s digestive tract.

At 6 weeks your breast milk has the highest level of antibodies to help fight off infection. At 3 months, the calories are increased to help your baby grow faster. Fast growth is important to get ready for upcoming developmental milestones. At 6 months, the levels of omega-3 fatty acids increase. Omega-3 fatty acids are essential for brain development. At 12 months the calories and omega-3 fatty acids increase again to help support muscle growth and brain development.

Why should I breastfeed?

Benefits for your baby!

Breastmilk is amazing and does so many good things for your baby. It is easily digestible provides antibodies, special hormones, and immune factors that support a healthy gut. It changes based on your baby’s immediate needs. In addition, here are some additional benefits of breastmilk:

• Encourages bonding with mom

• Higher IQ or academic performance

• Natural pain relief

• Peaceful sleep

• Healthy jaw and teeth development

• Reduced risk of obesity

• Reduced risk of illness including

o Ear infections

o Vomiting and diarrhea

o Pneumonia

o Urinary tract infections

o Certain types of spinal meningitis

• Reduced risk of hospitalization due to croup, bronchiolitis, or pneumonia

• May help reduce allergies

• Reduces the risk of Sudden Infant Death Syndrome (SIDS)

• Reduces the risk of developing

o Childhood acute leukemia and lymphoma

o Type 1 diabetes

o Type 2 diabetes

Benefits for you!

Your baby isn’t the only one who benefits from breastfeeding! There are many benefits for mom including:

• Faster recovery from birth

• Less uterine bleeding after birth and your uterus returns to normal size faster

• Some women note it helps them shed pregnancy weight faster because of the calories it takes to produce milk

• Breastfeeding releases good hormones that create peaceful and loving feelings

• Saves money and is good for the environment

• Better sleep patterns which means better rest

• Can help create space between pregnancies which is healthier for your body

• Reduced rate of cancers including

o Breast

o Ovarian

o Endometrial

• Reduced risk of osteoporosis (weak and brittle bones)

• Reduces the risk of chronic diseases such as

o Type 2 diabetes

o Rheumatoid arthritis

Breast milk provides your baby with optimal nutrition and immune support while providing you with immediate and long-term benefits. But nursing isn’t for everyone and it isn’t always easy. Next week’s blog will look at the challenges of breastfeeding, your partner’s role in breastfeeding, and discuss common breastfeeding issues and solutions.


Children’s Health Care of Newburyport, Massachusetts and Haverhill, Massachusetts is a pediatric healthcare practice providing care for families across the North Shore, Merrimack Valley, southern New Hampshire, and the Seacoast regions.  The Children’s Health Care team includes pediatricians and pediatric nurse practitioners who provide comprehensive pediatric health care for children, including newborns, toddlers, school aged children, adolescents, and young adults. Our child-centered and family-focused approach covers preventative and urgent care, immunizations, and specialist referrals. Our services include an on-site pediatric nutritionist, special needs care coordinator, and social workers. We also have walk-in appointments available at all of our locations for acute sick visits. Please visit where you will find information about our pediatric doctors, nurse practitioners, as well as our hours and services. 

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

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