What is postpartum fever, and why does it occur? It was a common occurrence in centuries past, but in recent times has become less frequent. Still, even 21st-century medicine cannot eliminate it completely.

Fever in the postpartum period occurs after 5% to 7% of births. Postpartum fever is defined as a temperature greater than 100.4 degrees F (38.0 degrees C) on at least two occasions.

These fevers cannot be ignored as they can represent serious infections. The first task is to identify the source. Most cases of postpartum fever resolve promptly when treated with appropriate antibiotics. Here is a review of common causes of postpartum fever:


Endometritis is an inflammation of the uterine lining and is the most common cause of postpartum fever. Endometritis usually appears 2 to 3 days after delivery and accounts for over half of postpartum infections. Symptoms include fever, uterine tenderness, and foul-smelling lochia (the vaginal bleeding after delivery).

Urinary Tract Infection/Pyelonephritis (Kidney Infection)

Women are more vulnerable to these infections after delivery, especially if they had a catheter in their bladder or an epidural. Symptoms include fever, difficulty urinating, painful urination, the feeling of needing to urinate often and urgently but little or nothing comes out, or urine that’s cloudy or bloody. Flank pain and fever may indicate pyelonephritis.


This breast infection affects as many as 1 in 10 nursing mothers. It is more likely in moms with cracked nipples. Mastitis can range in severity from a red and warm irritation to a flu-like infection. Symptoms include a painful, hard, warm, red area (usually only on one breast) and fever, chills, muscle aches, fatigue, or a headache.

Some women may develop a brief low-grade fever when their milk initially comes in due to engorgement. This usually resolves within 24 hours; a persistent fever suggests another cause.

Infected Incision

Women who had a C-section can get a wound infection, especially if they are overweight or labored first before their C-section. (After a vaginal birth, it’s possible to have one at the site of an episiotomy or tear, although this is very rare.) Symptoms include redness, discharge, swelling, warmth, or increasing tenderness or pain around an incision site or an incision that looks like it’s beginning to separate.

Less Common Causes

Atelectasis develops when tiny air sacs (alveoli) within the lung become deflated. It is a breathing complication after surgery that may cause fever. Symptoms include difficulty breathing, fever, and cough. Thrombophlebitis is an inflammatory process that causes a blood clot to form and block one or more veins, usually in the legs. Symptoms include redness, swelling, and tenderness in the affected area, and sometimes a low-grade fever.

What should I do if I think I have an infection?

Because an untreated infection can quickly become serious, it’s important to alert your doctor early if you have a fever or any of the other symptoms described above. You’ll be given antibiotics to treat the infection. Oral antibiotics are usually enough, but in some situations you may need intravenous antibiotics or possibly other treatment. You’ll probably begin to feel better within a few days of starting antibiotics, but it’s important to take the full course, even if your symptoms disappear. Drink plenty of fluids to prevent dehydration, and get as much rest as possible to help your body fight the infection.