Incidence of postpartum endometritis is affected mainly by the mode of delivery:
Vaginal deliveries: 1 to 3%
Scheduled caesarean deliveries (done before labor starts): 5 to 15%
Unscheduled caesarean deliveries (done after labor starts): 15 to 20%
Patient characteristics also affect incidence.
Etiology of Postpartum Endometritis
Endometritis may develop after chorioamnionitis during labor or postpartum. Predisposing conditions include
Prolonged rupture of the membranes
Repeated digital cervical examination
Retention or manual removal of placental fragments in the uterus
Bacterial colonization of the lower genital tract
Young maternal age
Low socioeconomic status
Infection tends to be polymicrobial; the most common pathogens include the following:
Gram-positive cocci (predominantly group B streptococci, Staphylococcus epidermidis, and Enterococcus species)
Anaerobes Overview of Anaerobic Bacteria Bacteria can be classified by their need and tolerance for oxygen: Facultative: Grow aerobically or anaerobically in the presence or absence of oxygen Microaerophilic: Require a low oxygen concentration... read more (predominantly peptostreptococci, Bacteroides species, and Prevotella species)
Gram-negative bacteria Introduction to Gram-Negative Bacilli Gram-negative bacilli are responsible for numerous diseases. Some are commensal organisms present among normal intestinal flora. These commensal organisms plus others from animal or environmental... read more (predominantly Gardnerella vaginalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis)
Infection may occur in the endometrium (endometritis), parametrium (parametritis), and/or myometrium (myometritis).
Uncommonly, peritonitis, pelvic abscess, pelvic thrombophlebitis Deep Venous Thrombosis (DVT) Deep venous thrombosis (DVT) is clotting of blood in a deep vein of an extremity (usually calf or thigh) or the pelvis. DVT is the primary cause of pulmonary embolism. DVT results from conditions... read more (with risk of pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are... read more ), or a combination develops. Rarely, septic shock Sepsis and Septic Shock Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection. In septic shock, there is critical reduction in tissue perfusion; acute failure... read more and its sequelae, including death, occur.
Symptoms and Signs of Postpartum Endometritis
Typically, the first symptoms of postpartum endometritis are lower abdominal pain and uterine tenderness, followed by fever—most commonly within the first 24 to 72 hours postpartum. Chills, headache, malaise, and anorexia are common. Sometimes the only symptom is a low-grade fever.
Pallor, tachycardia, and leukocytosis usually occur, and the uterus is soft, large, and tender. Discharge may be decreased or profuse and malodorous, with or without blood. When parametria are affected, pain and fever are severe; the large, tender uterus is indurated at the base of the broad ligaments, extending to the pelvic walls or posterior cul-de-sac.
Pelvic abscess may manifest as a palpable mass separate from and adjacent to the uterus or fever and abdominal pain that persists despite standard antibiotic therapy.
Diagnosis of Postpartum Endometritis
Usually tests to exclude other causes (eg, urinalysis and urine culture)
Diagnosis within 24 hours of delivery is based on clinical findings of pain, tenderness, and temperature > 38° C after delivery.
After the first 24 hours, postpartum endometritis is presumed present if no other cause is apparent in patients with temperature ≥ 38° C on 2 successive days. Other causes of fever and lower abdominal symptoms include urinary tract infections Introduction to Urinary Tract Infections (UTIs) Urinary tract infections (UTIs) can be divided into upper tract infections, which involve the kidneys ( pyelonephritis), and lower tract infections, which involve the bladder ( cystitis), urethra... read more (UTIs), wound infection, septic pelvic thrombophlebitis, and perineal infection. Uterine tenderness is often difficult to distinguish from incisional tenderness in patients who have had a cesarean delivery.
Patients with low-grade fever and no abdominal pain are evaluated for other occult causes, such as atelectasis Atelectasis Atelectasis is collapse of lung tissue with loss of volume. Patients may have dyspnea or respiratory failure if atelectasis is extensive. They may also develop pneumonia. Atelectasis is usually... read more , breast engorgement Breast engorgement Clinical manifestations during the puerperium (6-week period after delivery) generally reflect reversal of the physiologic changes that occurred during pregnancy (see table Normal Postpartum... read more , breast infection Mastitis Mastitis is painful inflammation of the breast, usually accompanied by infection. Fever later in the puerperium is frequently due to mastitis. Staphylococcal species are the most common causes... read more , UTI, and leg thrombophlebitis Superficial Venous Thrombosis Superficial venous thrombosis is a blood clot in a superficial vein of the upper or lower extremities or, less commonly, in one or more veins of the chest or breast (Mondor disease). Superficial... read more . Fever due to breast engorgement tends to remain ≤ 39° C. If temperature abruptly rises after 2 or 3 days of low-grade fever, the cause is probably an infection rather than breast engorgement.
Urinalysis and urine culture are usually done.
Endometrial cultures are rarely indicated because specimens collected through the cervix are almost always contaminated by vaginal and cervical flora. Endometrial cultures should be done only when endometritis is refractory to routine antibiotic regimens and no other cause of infection is obvious; sterile technique with a speculum is used to avoid vaginal contamination, and the sample is sent for aerobic and anaerobic cultures.
Blood cultures are rarely indicated and should be done only when endometritis is refractory to routine antibiotic regimens or clinical findings suggest septicemia.
If despite adequate treatment of endometritis, fever persists for > 48 hours (some clinicians use a 72-hour cutoff) without a downward trend in peak temperature, other causes, such as pelvic abscess and pelvic thrombophlebitis (particularly if no abscess is evident on scans), should be considered. Abdominal and pelvic imaging, usually by CT, is sensitive for abscess but detects pelvic thrombophlebitis only if the clots are large. If imaging shows neither abnormality, a trial of heparin is typically begun to treat presumed pelvic thrombophlebitis, usually a diagnosis of exclusion. A therapeutic response confirms the diagnosis.
Pearls & Pitfalls
Treatment of Postpartum Endometritis
Clindamycin plus gentamicin, with or without ampicillin
Treatment of postpartum endometritis is a broad-spectrum antibiotic regimen given IV until women are afebrile for 48 hours.
The first-line choice is clindamycin 900 mg IV every 8 hours plus gentamicin 1.5 mg/kg IV every 8 hours or 5 mg/kg once a day (1 Treatment reference Postpartum endometritis is uterine infection, typically caused by bacteria ascending from the lower genital or gastrointestinal tract. Symptoms are uterine tenderness, abdominal or pelvic pain... read more ); ampicillin 1 g every 6 hours is added if enterococcal infection is suspected or if no improvement occurs by 48 hours. Continuing treatment with oral antibiotics is not necessary.
Prevention of Postpartum Endometritis
Preventing or minimizing predisposing factors is essential. Vaginal delivery cannot be sterile, but aseptic techniques are used.
When delivery is cesarean, prophylactic antibiotics given within 60 minutes before surgery can reduce risk of endometritis by up to 75%.
Postpartum endometritis is more common after cesarean delivery, particularly if unscheduled.
The infection is usually polymicrobial.
Treat based on clinical findings (eg, postpartum pain, fundal tenderness, or unexplained fever), using broad-spectrum antibiotics.
Endometrial and blood cultures are not routinely done.
For cesarean delivery, give prophylactic antibiotics within 60 minutes before surgery.