Serious Illnesses and Breastfeeding

By: Joan Younger Meek, MD, MS, RD, FAAP, FABM, IBCLC

For some new parents, concerns about breastfeeding revolve less around their babies' physical condition than their own. Since some infectious diseases can be passed on to the baby through human milk, you will certainly want to discuss your medical history with your doctor and your baby's pediatrician.

The good news is that, in most cases, breastfeeding can still be safe and beneficial for your baby. Read on to learn about different illnesses and how they may affect breastfeeding.

A parent who tests positive for COVID-19 can breastfeed their infant. Ideally, pregnant and breastfeeding parents should receive the recommended COVID-19 vaccines. If the nursing parent wears a face mask and practices good handwashing, direct breastfeeding is possible. If the parent is seriously ill, their milk can be pumped or expressed and fed to the baby by a caregiver.

The lowest risk of passing human immunodeficiency virus (HIV) to an infant is to feed them baby formula or donor pasteurized human milk. However, people living with HIV who are receiving appropriate treatment with antiretroviral therapy during pregnancy, delivery and in the postpartum period have a very low risk of transmission of HIV through breast milk. (See "Breastfeeding for People With HIV: AAP Policy Explained.")

All pregnant people should be tested for HIV and consider repeat testing later in pregnancy if they are at risk for exposure to HIV. Before someone with HIV chooses to breastfeed, it is important to consult with a pediatrician or infectious disease specialist. Individual circumstances, viral load and other lab test results and medication treatment regimen need to be carefully considered first.

Hepatitis B virus has been detected in human milk, but breastfeeding has not been shown to increase the risk of infection to the baby. If you have Hepatitis B infection, there is no need to delay starting breastfeeding until your infant is immunized against hepatitis B.

If you are infected with hepatitis B, your baby should receive the vaccination for hepatitis B—along with hepatitis B immune globulin (HBIG)—as soon as possible after birth. Giving these two shots soon after delivery is highly effective in preventing the spread of hepatitis B from birth parent to infant. In fact, the hepatitis B vaccine is recommended for all babies, whether their birth parent is infected with hepatitis B or not.

Parents who have hepatitis C virus can safely breastfeed. Although an infant can be infected with the virus during pregnancy or delivery, breastfed infants do not have higher rates of hepatitis C than formula-fed infants. Breastfeeding may even help prevent the spread of hepatitis C from the mother to the baby, by providing antibodies passed to the baby through the breast milk.

If you are infected with hepatitis C and have cracked or bleeding nipples, however, you may want to hold off on breastfeeding (and discard pumped milk) until the nipple heals.

If you have tuberculosis (TB), you may breastfeed if you are currently taking medication for it. Mothers with untreated TB at the time of delivery should not breastfeed or be in direct contact with their newborn until they have started appropriate drug treatment and they are no longer infectious.

In most cases, you can safely breastfeed after you have been taking antibiotics for about two weeks and have been told by your doctor that you are no longer infectious. You should begin pumping soon after delivery, and your pumped milk may be fed to your infant by your partner, a nurse or another caregiver until you can breastfeed directly.

If you have had a positive TB skin test but a normal chest X-ray, talk to your doctor to see if you need to be treated with any medication, but you can breastfeed in this case.

Other types of infections need to be evaluated by your obstetrician, pediatrician or family physician, but few will prevent breastfeeding. This is true even when the infection or inflammation involves the breast itself—as in the case of mastitis, an infection of a section of the breast. This condition is typically treated with antibiotics, continued breastfeeding or expressing/pumping milk, drinking enough fluids, pain medication and rest.

If you have been diagnosed with breast cancer in the past and have been treated for it, you may be concerned about the effects of breastfeeding on you and your baby. Previous breast cancer does not mean that you cannot breastfeed your baby.

If you have had a mastectomy, you can feed from the remaining breast. If you have had a tumor removed from your breast or radiation treatments, you can still try feeding from that breast. You may find that your milk production is less, however. Always discuss your breastfeeding options with your physician.

Current cancer treatments may allow for partial or intermittent breastfeeding, depending upon the drugs or treatments being used. Breastfeeding should only be considered under the careful guidance of your oncologist (cancer doctor).

In the past, there have been concerns about the safety of breastfeeding after receiving breast implants. But there is no evidence that silicone breast implants cause any harm to the baby, and the newer saline (saltwater-filled) implant devices would not be expected to cause any harm to the baby, either.

In most cases, plastic surgery to enlarge or reconstruct the breasts after a mastectomy should not interfere significantly with your ability to breastfeed, provided the nipples have not been moved and no milk ducts have been cut. With more recent surgical procedures, and with surgeons paying attention to the patient's desire to breastfeed in the future, it is more likely that breastfeeding, or at least partial breastfeeding, will be successful.

If you have had any surgical procedure on your breast, even a biopsy, make sure that your baby's doctor knows this. By all means begin breastfeeding, making sure that your pediatrician or family physician closely monitors your infant to be certain that they are getting enough breast milk.

Breastfeeding & COVID-19: What Parents Need to Know

How Breastfeeding Benefits Your Baby's Immune System

Breastfeeding & HIV: AAP Shifts Position

Joan Younger Meek, MD, MS, RD, FAAP, FABM, IBCLC, is a Professor Emeritus in the Department of Clinical Sciences at the Florida State U​niversity College of Medicine and a past chair of the American Academy of Pediatrics Section on Breastfeeding.