Mastitis, the inflammation of breast tissue, is overwhelmingly associated with the postpartum period and breastfeeding. However, it is possible for this condition to occur during pregnancy, a rare occurrence known as antepartum or prepartum mastitis. Mastitis often progresses to a bacterial infection that requires prompt medical attention.
Understanding Mastitis: Beyond Breastfeeding
Mastitis is generally divided into two categories: lactational (puerperal) and non-lactational. The lactational form is typically caused by milk stasis, where milk buildup allows bacteria to multiply. Non-lactational mastitis, which occurs in individuals who are not breastfeeding, follows a different biological pathway to infection.
During pregnancy, hormonal changes prepare the breasts for milk production, causing tissue remodeling. These changes make the breast tissue susceptible to infection even without mature milk flow. In non-lactational cases, bacteria enter the breast duct system or localized inflammation progresses to infection, allowing an infection to take hold despite the lack of active milk removal.
Specific Causes of Prepartum Mastitis
Since milk stasis is not the primary mechanism, prepartum mastitis is often linked to non-lactational factors that allow skin bacteria to infiltrate the tissue. Trauma to the nipple or areola, such as from friction, skin irritation, or nipple piercings, can create an entry point for common skin flora like Staphylococcus aureus. Once the bacterial barrier is breached, the infection can spread rapidly within the breast tissue.
Another contributing factor is periductal mastitis, which involves inflammation and infection of the ducts directly beneath the nipple. This form is sometimes associated with smoking or duct ectasia, where the milk ducts widen and thicken, potentially leading to fluid accumulation and clogging unrelated to active milk production. The hormonal shifts of pregnancy also cause a temporary suppression of certain immune responses, making the body less effective at fighting off localized bacterial invasions.
Some rare forms of non-infectious inflammation, such as idiopathic granulomatous mastitis, can also present during pregnancy, though the exact cause is often unknown. The presence of inflammation combined with an impaired local defense system can predispose a pregnant individual to a painful infection.
Identifying Symptoms and When to Seek Help
The symptoms of acute mastitis are usually rapid in onset and include both localized and systemic signs. Locally, the affected breast typically displays a specific area of pain, warmth, swelling, and redness. Many individuals also notice a hard lump or wedge-shaped area of hardness where the inflammation is most concentrated.
Systemic symptoms can mimic the flu, often preceding the localized breast discomfort. These include a persistent fever, chills, body aches, and fatigue. It is important to distinguish these symptoms from the normal, hormone-related breast tenderness common in pregnancy, which typically does not involve high fever or localized, spreading redness.
You should contact your obstetrician or healthcare provider immediately if you experience a fever of 101°F (38.3°C) or higher, or if the localized pain and redness rapidly worsen over 24 hours. Timely intervention is required because untreated mastitis can lead to a breast abscess—a localized collection of pus that may require surgical drainage. Persistent or worsening symptoms warrant a prompt medical evaluation to prevent complications.
Treatment and Management During Pregnancy
The primary treatment for mastitis, even during pregnancy, is a course of antibiotics to clear the bacterial infection. The prescribed antibiotics, such as dicloxacillin or cephalexin, must be confirmed by your healthcare provider to be safe for use during pregnancy. For individuals with a penicillin allergy, alternatives like clindamycin may be prescribed to ensure effective treatment without risk to the fetus.
Supportive care measures are used alongside antibiotics to manage discomfort and inflammation. Applying cold compresses to the affected area can help reduce swelling and alleviate pain. Over-the-counter pain relievers such as acetaminophen (Tylenol) are considered safe for use during pregnancy and can help control fever and body aches.
It is recommended to avoid non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, especially in the third trimester, making acetaminophen the safer option. Gentle massage toward the areola may assist in relieving localized congestion. A follow-up appointment is necessary to ensure the infection has completely cleared.