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Endometritis


Endometritis

Article Author:
Michael Taylor
Article Editor:
Leela Sharath Pillarisetty
Updated:
4/18/2020 12:24:18 PM
For CME on this topic:
Endometritis CME
PubMed Link:
Endometritis

Introduction

Endometritis is inflammation of the uterine lining. It can affect all layers of the uterus. The uterus is typically aseptic. However, the travel of microbes from the cervix and vagina can lead to inflammation and infection. This condition usually occurs as a result of the rupture of membranes during childbirth. Endometritis is the most common postpartum infection. Puerperal endometritis is 25 times more common in patients that underwent cesarean sections. Most cases of postpartum endometritis are polymicrobial, involving aerobic and anaerobic bacteria.

Etiology

Endometritis results from the travel of normal bacterial flora from the cervix and vagina. The uterus is sterile until the amniotic sac ruptures during childbirth. Bacteria is more likely to colonize uterine tissue that has been devitalized, bleeding, or otherwise damaged (such as during a cesarean section).[1] 

Between 60% and 70% of infections are due to both aerobes and anaerobes. Examples of anaerobic species are Peptostreptococcus, Peptococcus, BacteroidesPrevotella, and Clostridium. Examples of aerobic species are primarily groups A and B StreptococciEnterococcusStaphylococcus, Klebsiella pneumoniae, Proteus species, and Escherichia coli. Uterine tissue damaged by cesarean section is particularly susceptible to Streptococcus pyogenes and Staphylococcus aureusChlamydia endometritis often presents at a later date, seven or more days postpartum.[2][3]

Epidemiology

Puerperal endometritis is the most common postpartum infection.[4] In patients without risk factors, following normal spontaneous vaginal delivery, there is an incidence of 1% to 2%. Risk factors, however, can increase this rate to a 5% to 6% risk of infection following vaginal delivery. Risk factors include chorioamnionitis, low socioeconomic status, prolonged labor, membrane rupture, multiple cervical examinations, internal fetal monitoring, young maternal age, nulliparity, obesity, meconium-stained amniotic fluid and bacterial colonization of the lower genital tract with bacteria such as Group B streptococcus (GBS), Chlamydia trachomatisMycoplasma hominisUreaplasma urealyticum, or Gardnerella vaginalis. The route of delivery is the most significant risk factor for endometritis, with cesarean deliveries (especially for multifetal gestation) having a much higher likelihood of leading to endometritis and a 25-fold increase in infection-related mortality.[5][6]

Pathophysiology

Most cases of endometritis result from childbirth. Specifically, the rupture of the amniotic sac allows translocation of normal bacterial flora from the cervix and vagina to the usually aseptic uterus. This bacteria is more likely to colonize uterine tissue that has been devitalized, bleeding, or otherwise damaged (such as during a cesarean section). This bacteria can invade the endometrium-, myometrium-, and perimetrium, causing inflammation and infection.

History and Physical

Patients with endometritis often have fever as their first sign of infection. Additional common complaints are abdominal pain (commonly suprapubic in location), foul-smelling and purulent lochia. Like many infections, the grade of the fever is often indicative of the severity of the infection. On physical exam, suprapubic and uterine tenderness are often present on abdominal and pelvic exams, respectively. Vital sign abnormalities such as fever, tachycardia, and hypotension may also be present. Endometritis caused by Group A streptococcus is often particularly severe, resulting in a clinical picture consisting of sepsis, diarrhea, pain out of proportion. This condition can quickly develop into toxic shock, and necrotizing fasciitis, so great care is necessary when looking after such patients. 

Evaluation

Endometritis is primarily a clinical diagnosis based on the history, physical, and presence of risk factors. In equivocal cases or to establish the severity of infection, laboratory and imaging evaluation can be helpful.

A leukocytosis of 15000 to 30000 cells/microL is common. Vaginal delivery, and cesarean section particularly, however, can cause an inflammatory leukocytosis. The CBC, therefore, is just one set of values in the greater clinical picture that will help aid the correct diagnosis. Cervical cultures obtained before antibiotic administration can be helpful for appropriate antibiotic selection. Vaginal cultures are often contaminated and can mislead providers to inadequate antibiotic coverage. Blood cultures should be obtained if there is a high enough clinical suspicion for sepsis and/or bacteremia. 

For imaging, ultrasound often helps to rule out other diagnoses in the postpartum patient with abdominal pain and fever. Such diagnoses include retained products of conception, infected hematoma, and uterine abscesses. For patients with endometritis, findings consist of a thickened, heterogeneous endometrium, intracavitary fluid, and foci of air. Some of these findings, however, may be present as normal variants, so a good clinical acumen is necessary when comparing ultrasound results to other diagnostic findings. For instance, up to 24% of normal postpartum patients may have clots and debris in the uterus. Gas in the endometrium may also be normal for up to 3 weeks postpartum. Conversely, patients with endometritis may have a normal pelvic ultrasound. Computed tomography can show the same positive findings as ultrasound plus possible perimetrium and/or intrauterine inflammation and infection.[7][8][9][10]

Treatment / Management

The threshold for obstetrics should be low in any provider considering a diagnosis of endometritis. Oral antibiotic regimens are an option for mild disease. The options are similar to those used for pelvic inflammatory disease:

  • Doxycycline 100 mg every 12 hours + metronidazole 500 mg every 12 hours. Doxycycline is not contraindicated in breastfeeding mothers if its use is for less than three weeks.
  • Levofloxacin 500 mg every 24 hours + metronidazole 500 mg every 8 hours. Levofloxacin should be avoided in breastfeeding mothers.
  • Amoxicillin-clavulanate 875 mg/125 mg every  12 hours.[11]

For patients with moderate to severe endometritis and/or patients with endometritis s/p cesarean section, intravenous antibiotics and admission are recommended. Options are as follows:

  • Gentamicin 1.5 mg/kg IV every 8 hours or 5 mg/kg IV every 24 hours and clindamycin 900 mg every 8 hours.
    • QD gentamicin dosing is associated with a shorter hospitalization time compared with TID and has been shown to be just as effective.
    • There is not adequate data at this time regarding the effects of this regimen on breastfeeding infants or the effect of gentamicin on maternal renal function.
  • For patients with endometritis due to GBS resistant to clindamycin, piperacillin-tazobactam and ampicillin-sulbactam may be used.[12][13]

Clinical improvement in response to antibiotics typically occurs in 48 to 72 hours. If there is no clinical improvement within 24 hours, providers should consider adding ampicillin 2 g initially, followed by 1 g every 4 hours for enhanced Enterococcus coverage. For those that do not improve within 72 hours, providers should broaden their differential diagnosis to include other infections such as pneumonia, pyelonephritis, pelvic septic thrombophlebitis. IV antibiotics should continue until the patient becomes afebrile for at least 24 hours in addition to an improvement in the patient’s pain and leukocytosis. At this time, there is no substantial evidence demonstrating that continuing antibiotics in PO form following such clinical improvement improves significant patient-oriented outcomes.[14]

Differential Diagnosis

In the patient with postpartum fever and abdominal pain, diagnoses other than endometritis that merit consideration include urinary tract infections (including pyelonephritis), pneumonia, septic pelvic thrombophlebitis. The clinician should keep an open mind to these diagnoses, especially if antibiotic and/or surgical management for endometritis is not leading to clinical improvement.

Prognosis

If untreated, the fatality rate of endometritis is approximately 17%. Thankfully this is reduced to 2% with proper recognition and treatment. Cesarean deliveries (especially for multifetal gestation) have a 25-fold increase in infection-related mortality.[11]

Complications

Approximately 1% to 4% of patients will have complications such as sepsis, abscesses, hematomas, septic pelvic thrombophlebitis, and necrotizing fasciitis. Such complications can then lead to uterine necrosis, requiring a hysterectomy for infection resolution. Surgical intervention may also be necessary if the infection has produced a drainable fluid collection.[6]

Deterrence and Patient Education

Due to the increased prevalence and mortality of endometritis secondary to cesarean sections, ACOG recommends prophylactic antibiotics before cesarean deliveries. A recent Cochrane review showed a significant reduction in the risk of postpartum infections, including endometritis, when such antibiotics were given. Furthermore, obstetricians should have a thoroughly informed consent conversation regarding the cesarean section, specifically including the risks of postpartum infections. Risks and benefits regarding vaginal vs. cesarean delivery should undergo review, and the patient should make a properly-educated decision.

Pearls and Other Issues

  • Endometritis is an inflammation and infection of the uterus.
  • Postpartum endometritis is the most common postpartum infection.
  • Fever is the most common symptom. Abdominal pain, vaginal bleeding, and vaginal discharge in febrile postpartum patients should raise clinical suspicion for this diagnosis.
  • Early identification and obstetric consultation are essential.
  • The severity of the disease can vary. If necessary, resuscitation, including early antibiotic administration, should be the primary focus.

Enhancing Healthcare Team Outcomes

Endometritis is the most common postpartum infection. Disease severity can range from mild to severe, with treatment regimens ranging from outpatient PO antibiotics with adequate obstetrics follow up and return precautions to inpatient hospitalization with IV antibiotics and surgery (hysterectomy, fluid drainage, for example).

Patients will often present to generalists: non-obstetrics primary care providers, urgent care centers, and emergency departments. Early obstetric consultation is critical. Such a consult can help aid efficient and appropriate diagnostics and treatment. If imaging is needed, ultrasonographers, radiology technicians, and diagnostic radiologists may all prove useful. This is why an interprofessional team approach to patient care is necessary. For ideal antibiotic choice, dosing, and administration, a clinical pharmacist may be helpful; they can validate antimicrobial therapy against the latest antibiogram data, check for interactions, and alert the staff to potential adverse effects. If operative intervention is required, an anesthesiologist is also necessary for a successful surgery.

To ensure that a patient with endometritis receives optimal care, an effective interprofessional approach is crucial. Prompt involvement of appropriate specialists, as well as strong communication between providers, can make a significant difference in the patient's clinical course, morbidity, and mortality. Obstetrical nurses should promptly report fevers to managing providers, administer treatment, and educate patients. With interprofessional collaboration, patient outcomes will improve. [Level 5]


References

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[2] Morgan J,Roberts S, Maternal sepsis. Obstetrics and gynecology clinics of North America. 2013 Mar;     [PubMed PMID: 23466138]
[3] Dalton E,Castillo E, Post partum infections: A review for the non-OBGYN. Obstetric medicine. 2014 Sep;     [PubMed PMID: 27512432]
[4] Chaim W,Bashiri A,Bar-David J,Shoham-Vardi I,Mazor M, Prevalence and clinical significance of postpartum endometritis and wound infection. Infectious diseases in obstetrics and gynecology. 2000;     [PubMed PMID: 10805361]
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[7] Laifer-Narin SL,Kwak E,Kim H,Hecht EM,Newhouse JH, Multimodality imaging of the postpartum or posttermination uterus: evaluation using ultrasound, computed tomography, and magnetic resonance imaging. Current problems in diagnostic radiology. 2014 Nov-Dec;     [PubMed PMID: 25041975]
[8] Plunk M,Lee JH,Kani K,Dighe M, Imaging of postpartum complications: a multimodality review. AJR. American journal of roentgenology. 2013 Feb;     [PubMed PMID: 23345378]
[9] Nalaboff KM,Pellerito JS,Ben-Levi E, Imaging the endometrium: disease and normal variants. Radiographics : a review publication of the Radiological Society of North America, Inc. 2001 Nov-Dec;     [PubMed PMID: 11706213]
[10] Vandermeermd FQ,Wong-You-Cheong JJ, Imaging of acute pelvic pain. Topics in magnetic resonance imaging : TMRI. 2010 Jul;     [PubMed PMID: 22082769]
[11] Meaney-Delman D,Bartlett LA,Gravett MG,Jamieson DJ, Oral and intramuscular treatment options for early postpartum endometritis in low-resource settings: a systematic review. Obstetrics and gynecology. 2015 Apr;     [PubMed PMID: 25751198]
[12] Mackeen AD,Packard RE,Ota E,Speer L, Antibiotic regimens for postpartum endometritis. The Cochrane database of systematic reviews. 2015 Feb 2;     [PubMed PMID: 25922861]
[13] Del Priore G,Jackson-Stone M,Shim EK,Garfinkel J,Eichmann MA,Frederiksen MC, A comparison of once-daily and 8-hour gentamicin dosing in the treatment of postpartum endometritis. Obstetrics and gynecology. 1996 Jun;     [PubMed PMID: 8649712]
[14] DeNoble AE,Kuller JA,Heine RP,Dotters-Katz S, Antibiotics for the Prevention and Treatment of Postsurgical Obstetric Infections. Obstetrical     [PubMed PMID: 30169886]