Why Some People Shouldn't or Can't Breastfeed

Parent bottle feeding their baby
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Breastfeeding is beneficial for both parents and babies, which is why experts recommend exclusive breastfeeding for the first six months of a baby's life. However, while most birthing parents can breastfeed, there are sometimes contraindications.

There are a few reasons why someone should not or may not be able to breastfeed their baby. For example, some parents cannot produce a healthy breast milk supply, while others may take certain medications or need to undergo a medical treatment that isn't breastfeeding safe. There are also a few medical conditions that aren't compatible with breastfeeding. In some situations, the parent may be able to pump and provide their baby with breast milk in a bottle, or they may be able to stop breastfeeding temporarily then restart.

Low Breast Milk Supply

A lot of parents worry that they may not be producing enough milk for their baby, but in reality, only a small percentage of people who want to breastfeed can't due to a true low breast milk supply. A true low milk supply is rare, and it is usually the result of an underlying condition. With treatment, some issues can be corrected but some problems cannot be resolved. The causes of a true low milk supply include:

  • Insufficient glandular tissue (hypoplastic breasts)
  • Polycystic ovary syndrome (PCOS)
  • Hypothyroidism
  • Previous breast surgery, such as mastectomy or a breast reduction surgery
  • Prior radiation treatment for breast cancer

If you have a true low milk supply, you may not be able to breastfeed exclusively. However, supplementing with infant formula or donor milk is nothing to be ashamed of. You are simply helping your baby meet their nutrition needs—which is exactly what a good parent does.

Plus, breastfeeding provides more than just nutrition, so you can still put your baby to your breast and allow your infant to nurse for comfort and security. Even if they are only getting a small amount of breast milk, it's still good for them—and it allows you to bond.

Contraindicated Medicines

Many medications, including those that require a prescription, are compatible with breastfeeding, but some are not. Some medications can pose a risk to a breastfed babies when taken by the breastfeeding parent, such as:

  • Chemotherapy drugs
  • Antiretroviral medications
  • Radioactive iodine
  • Some sedatives
  • Seizure medication
  • Medicines that may cause drowsiness
  • Medications that suppress breathing

Other medications can cause a decrease in the milk supply, making them a less favorable choice for breastfeeding parents. These include cold and sinus medications that contain pseudoephedrine, as well as certain types of hormonal birth control.

Discuss all medications with your doctor before breastfeeding—not just new ones. They can let you know if they're safe to use while you're breastfeeding.

Substance Use

It is not safe to use recreational drugs while breastfeeding because these substances can get into your breast milk and pass to the baby, which can cause irritability, sleepiness, poor feeding, growth problems, neurological damage, or even death. If you're struggling with addiction, help is available.

If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

If you are sober or in treatment, you may be able to breastfeed safely. If you have a history of drug use but no longer use substances and want to nurse your baby, consult your healthcare provider for guidance.

Infectious Diseases

Many common infections are easily treated and do not interfere with breastfeeding or harm the baby. However, there are a few infectious diseases that can pass to a baby through breast milk, and in some cases, the risk of transmission outweighs the benefits of breastfeeding.


The human immunodeficiency virus (HIV) is the virus that causes acquired immunodeficiency syndrome (AIDS). A mother who has HIV can pass the virus to her child through breastfeeding and her breast milk.

Since AIDS does not have a cure, a mother who is HIV positive should not breastfeed if she lives in an area of the world where a safe alternative such as infant formula is available. However, in countries where a safe replacement is not possible, exclusive breastfeeding may be recommended.


The human T-cell lymphotropic virus 1 (HTLV-1) is a virus that can lead to leukemia and lymphoma. Human T-cell lymphotropic virus 2 (HTLV-2) can cause brain and lung issues. These viruses may not cause any symptoms at all, but they are lifelong conditions for which there is no cure. Since HTLV-1 and HTLV-2 can pass to a baby through breast milk, babies born to parents who are positive for HTLV should not breastfeed.

However, studies show that HTLV-1 cells can be destroyed by the freezing and thawing of expressed breast milk if the milk is frozen at a temperature of -4 degrees F (-20 C) or below for more than 12 hours.

Active Tuberculosis Infection

Tuberculosis (TB) is a bacterial infection in the lungs. It is passed through respiratory droplets, not by breastfeeding or breast milk. However, a parent can give active tuberculosis to a child through coughing, sneezing, and touching. When a parent has active TB, but their baby does not, the parent should not be in close contact with the baby and therefore should not breastfeed.

Since tuberculosis is not transmitted through breast milk, a baby can receive pumped breast milk until breastfeeding can begin after about two weeks of treatment. When both breastfeeding parent and baby have TB, they can stay together during treatment, and the baby can breastfeed.

Herpes on the Breast

Herpes is not passed through breast milk, so as long as the lesions are not on the breast, any lesions on other body parts are covered, and thorough hand washing is performed, it is safe to breastfeed. However, when there are active lesions on the breast, breastfeeding is dangerous as the herpes virus can be deadly to a baby.

Baby's Medical Needs

Most babies can breastfeed. Even infants born with conditions such as prematurity, cleft lip and palate, or Down syndrome who may not be able to take the breast right away can still take pumped breast milk in a bottle. With patience, time, and help, these babies may go on to breastfeed successfully.

It's only when a baby is born with one of a few rare genetic metabolic conditions that breastfeeding may not be possible. But, even then, sometimes a baby can still partially breastfeed.

Classic Galactosemia

Galactosemia is the body’s inability to break down galactose. Galactose is a part of the milk sugar lactose, and lactose is the main sugar in breast milk. So, if a baby tests positive for classic galactosemia, they cannot breastfeed or take breast milk in a bottle. The child will need a special infant formula and a galactose-free diet to prevent severe complications such as jaundice, vomiting, diarrhea, long-term developmental problems, and death.

A less severe form of galactosemia is called Duarte's galactosemia. Children with Duarte’s galactosemia can break down some galactose. Under the direct care of a doctor specializing in metabolic disorders, it may be possible to breastfeed babies with Duarte's galactosemia while supplementing with the galactose-free formula. The doctor will have to monitor the baby's galactose levels frequently to make sure that they stay under control.

Phenylketonuria (PKU)

A baby with PKU can't break down phenylalanine, an amino acid. If phenylalanine builds up in the baby's body, it can cause brain damage. Therefore, babies with PKU need a diet low in phenylalanine.

There is a special infant formula for infants with PKU. But, since breast milk is low in phenylalanine, a baby with PKU may be able to combine breastfeeding and formula feeding with a special formula. The amount of breastfeeding needs to be controlled, and the baby has to have regular blood work and careful monitoring.

Maple Syrup Urine Disease

A baby born with maple syrup urine disease cannot break down the amino acids leucine, isoleucine, and valine. When these amino acids accumulate in the baby's blood, they give off a sweet maple syrup scent that is noticeable in the urine, ear wax, and sweat. The build-up of these amino acids can cause sleepiness, poor feeding, vomiting, seizures, coma, and death.

To fulfill the baby's nutritional needs, your baby's doctor will order a special infant formula that does not contain the three amino acids leucine, isoleucine, valine. The doctor may also recommend partial breastfeeding if the amount of breast milk is carefully measured and the baby is monitored closely.

A Word From Verywell

Every parent and baby is unique, and so is every breastfeeding situation. If you want to breastfeed, but you're told that you can't or shouldn't, it can be devastating. It's OK to feel angry or sad and to take the time to work through your emotions. You may also find it helpful to talk about your feelings with your doctor, your spouse, or someone you trust.

As hard as it may be, try to remember that breastfeeding isn't the only way to provide nutrition and build a close relationship with your child. Your baby can get the nutrition they need from donor breast milk or infant formula. Bonding and connections will strengthen each time you hold your child, talk to them, comfort them, and even feed them with a bottle. Just because you can't or shouldn't breastfeed doesn't mean you can't be a great parent to a happy, healthy child.

7 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Donna Murray, RN, BSN
Donna Murray, RN, BSN has a Bachelor of Science in Nursing from Rutgers University and is a current member of Sigma Theta Tau, the Honor Society of Nursing.