Mastitis is a breast infection that’s usually caused by incomplete drainage of milk ducts. It’s a very common infection while breastfeeding, but it can happen rarely during pregnancy.

You may experience flu-like symptoms (fevers, chills, muscle aches), significant tenderness in one breast, and usually some obvious skin redness over a portion of one of your breasts. During pregnancy, it happens more commonly in patients who are breastfeeding another child. Otherwise, in rare instances, mastitis can occur later in pregnancy when your milk starts coming in.

Since breast tenderness is a very common pregnancy symptom, especially early in pregnancy, keep an eye out for flu-like symptoms and one-sided redness as well as increased pain. Your obstetrical provider can assess and prescribe pregnancy-friendly antibiotics as needed.