A fever often causes concern for a breastfeeding parent, whose first thought is naturally the baby’s safety. Parents commonly question if an illness, especially one causing a fever, can be transmitted through human milk. Understanding the science behind breast milk composition helps alleviate this worry and guide the decision to continue nursing.
Breast Milk Safety During Maternal Illness
The immediate answer for most common illnesses that cause a fever, such as colds or the flu, is that it is safe and highly recommended to continue breastfeeding. The fever is simply a sign that the mother’s immune system is actively fighting an infection. Most viruses and bacteria responsible for common maternal infections are not passed to the infant through human milk.
The primary mechanism of protection is passive immunity, which activates as soon as the mother is exposed to a pathogen. The mother’s body quickly produces specific immunoglobulin A (IgA) antibodies tailored to the current illness. These protective factors are then transferred directly to the baby via the milk, often before the mother even recognizes she is sick.
Secretory IgA antibodies are not absorbed into the infant’s bloodstream but instead coat the mucous membranes of the baby’s gut and respiratory tract. This localized action helps block the entry of infectious agents, effectively reducing the baby’s risk and severity of the illness. Continuing to nurse ensures the infant receives this continuously updated, specific immunological defense against the exact germs in their shared environment.
Managing Supply and Maternal Comfort
While the milk remains safe, illness can present practical challenges for the mother concerning comfort and supply. A fever often leads to dehydration, which can temporarily decrease milk volume. Maintaining a high fluid intake, including water and electrolyte-rich beverages, is important for recovery and sustaining milk volume.
Frequent rest and prioritizing sleep are helpful measures to support the body’s immune response and sustain lactation. For managing fever and discomfort, many common over-the-counter medications are compatible with breastfeeding, such as acetaminophen and ibuprofen for short-term use. However, the mother should avoid medications containing pseudoephedrine, a common decongestant, as it can constrict blood vessels and reduce milk supply. Consulting with a healthcare provider or pharmacist about any medication is the best way to ensure it is appropriate while nursing.
Conditions Requiring Medical Consultation or Temporary Cessation
While most common fevers do not require stopping nursing, specific medical conditions mandate consultation with a physician.
Permanent Cessation
Permanent cessation is recommended for mothers with untreated Human Immunodeficiency Virus (HIV) or Human T-cell Lymphotropic Virus (HTLV) types I or II. These viruses can be transmitted through human milk, posing a risk that outweighs the benefits of nursing.
Temporary Cessation Due to Infection
Temporary cessation is sometimes necessary for mothers with active, untreated tuberculosis, due to the high risk of airborne transmission during close contact. In this case, the mother can express milk to be fed to the baby by a healthy caregiver. Nursing can often resume after two weeks of treatment when the mother is no longer infectious. Temporary interruption is also required for active herpes lesions directly on the breast, as the virus can be transmitted by direct contact with the sore.
Temporary Cessation Due to Treatment
Certain medical treatments also necessitate a temporary halt to nursing. These include undergoing chemotherapy with antimetabolite or cytotoxic agents, or diagnostic imaging involving radioactive isotopes. These substances can pass into the milk and are harmful to the infant. If temporary cessation is required, the mother must regularly pump and discard the milk to maintain her supply and prevent painful engorgement. Any decision to interrupt nursing should be made only after a thorough discussion with a healthcare provider aware of the current illness and all medications being taken.