Definition

This is infection of the endometrium. It can be divided into pregnancy-related (obstetric) and non-obstetric, acute and chronic.

The accepted wisdom is that infection, usually having travelled from the lower genital tract, attacks the endometrium.
Spread occurs from there to the tubes and ovaries, causing salpingo-oophoritis. More recent work has questioned whether endometritis is a discrete condition or part of a spectrum which may also involve pelvic inflammatory disease (PID).¹

• Acute endometritis is characterised by the presence of more than five neutrophils in a 400 power field in the endometrial glands.
• Chronic endometritis is characterised by the presence of more than one plasma cell, (and lymphocytes) in a 120 power field in the endometrial stroma.

Epidemiology

• 1-3% after spontaneous (uncomplicated) vaginal delivery.
• May rise as high as 19-40% after Caesarean section, depending on risk factors surrounding the decision to operate, and protocol on prophylactic antibiotics. Prophylaxis with cephalosporin has not been shown to reduce risk of endometritis, but extending coverage, (with doxycycline and azithromycin) has.^2,3

It is the most common cause of postnatal morbidity between day two and day ten. Due to the nature of the complaint, it is most common in females of reproductive age.

Aetiology

There is usually a mix of 2-3 organisms involved; some will be found in normal vaginal flora. Causative organisms include:

• Gram-positive cocci - Staphylococcus spp., Streptococcus spp. (esp Group B streptococcus)
• Gram-negative - E. coli, Klebsiella spp., Proteus spp., Enterobacter spp., Gardnerella vaginalis, Neisseria spp.
• Anaerobes - Bacteroides spp. Peptostreptococcus spp.
• Others - Mycoplasma spp., Ureaplasma spp., tuberculosis

Acute endometritis

• Obstetric: postpartum infection is the most common precursor to acute endometritis.
• Non-obstetric: PID and invasive gynaecological procedures are the most common precursors.

Chronic endometritis

Chlamydial and gonococcal infection are not commonly found in chronic endometritis compared with other bacteria, e.g. Mycoplasma spp.

• Obstetric: associated with retained products of conception after delivery or elective abortion.
• Non-obstetric: associated with chronic infections, e.g. tuberculosis,⁴ bacterial vaginosis, and after intrauterine contraceptive device fitting.

Risk factors

Obstetric risk factors

• Caesarean section (particularly if HIV positive⁵)
• Prolonged rupture of membranes
• Severe meconium staining in liquor⁶ - although this has been disputed⁷
• Long labour with multiple examinations
• Manual removal of placenta⁸
• Mother's age at extremes of reproductive span
• Low socioeconomic status, e.g. home delivery in poor hygiene environment⁹
• Maternal anaemia
• Prolonged surgery
• Internal fetal monitoring
• General anaesthetic

Non-obstetric risk factors

• Intrauterine contraceptive device
• Absence of normal cervical mucus plug
• Menstrual fluid within cavity
• Instrumentation of the uterus
• Douching¹⁰
• Unprotected sexual intercourse
• Multiple sexual partners

Presentation

Symptoms

Number and severity of symptoms can vary markedly from patient-to-patient, but usually include:

• Fever
• Abdominal pain
• Offensive smelling lochia
• Abnormal vaginal bleeding - postpartum haemorrhage
• Abnormal vaginal discharge
• Dyspareunia
• Dysuria
• General malaise

Signs

• Raised temperature
• Pain and tenderness, which may radiate to the adnexae
• Tachycardia

Investigations

• Blood cultures are positive in 10-30%
• Check mid-stream urine
• High vaginal swab for gonorrhoea/chlamydia

There is nothing to be gained from ultrasound.¹¹

Management

Drugs

• IV clindamycin and gentamicin tds until afebrile for greater than 24 hours. Oral follow-up treatment is not required.^12,13
• If less systemically unwell, oral combinations of amoxicillin, gentamicin and metronidazole.
• Use doxycycline if chlamydia is suspected.

Differential diagnosis

• Appendicitis
• PID
• Pyelonephritis
• Urinary tract infection
• Viral syndrome

Complications

• Wound infection
• Peritonitis
• Adnexal infection
• Pelvic abscess
• Pelvic haematoma

Prognosis

90% of cases treated with antibiotics improve within 48-72 hours.¹³ If this is not the case, the patient should be re-evaluated.

Document references

1. Ross JD; What is endometritis and does it require treatment? Sex Transm Infect. 2004 Aug;80(4):252-3.
2. Bagratee JS, Moodley J, Kleinschmidt I, et al; A randomised controlled trial of antibiotic prophylaxis in elective caesarean delivery. BJOG. 2001 Feb;108(2):143-8. [abstract]
3. Andrews WW, Hauth JC, Cliver SP, et al; Randomized clinical trial of extended spectrum antibiotic prophylaxis with coverage for Ureaplasma urealyticum to reduce post-cesarean delivery endometritis. Obstet Gynecol. 2003 Jun;101(6):1183-9. [abstract]
4. Gungorduk K, Ulker V, Sahbaz A, et al; Postmenopausal tuberculosis endometritis. Infect Dis Obstet Gynecol. 2007;2007:27028. Epub 2007 May 8. [abstract]
5. Louis J, Landon MB, Gersnoviez RJ, et al; Perioperative morbidity and mortality among human immunodeficiency virus infected women undergoing cesarean delivery. Obstet Gynecol. 2007 Aug;110(2 Pt 1):385-90. [abstract]
6. Tran SH, Caughey AB, Musci TJ; Meconium-stained amniotic fluid is associated with puerperal infections. Am J Obstet Gynecol. 2003 Sep;189(3):746-50. [abstract]
7. Panichkul S, Boonprasertmd K, Komolpismd S, et al; The association between meconium-stained amniotic fluid and chorioamnionitis or endometritis. J Med Assoc Thai. 2007 Mar;90(3):442-7. [abstract]
8. Dehbashi S, Honarvar M, Fardi FH; Manual removal or spontaneous placental delivery and postcesarean endometritis and bleeding. Int J Gynaecol Obstet. 2004 Jul;86(1):12-5. [abstract]
9. Maharaj D; Puerperal pyrexia: a review. Part I. Obstet Gynecol Surv. 2007 Jun;62(6):393-9. [abstract]
10. Ness RB, Soper DE, Holley RL, et al; Douching and endometritis: results from the PID evaluation and clinical health (PEACH) study. Sex Transm Dis. 2001 Apr;28(4):240-5. [abstract]
11. Mulic-Lutvica A, Axelsson O; Postpartum ultrasound in women with postpartum endometritis, after cesarean section and after manual evacuation of the placenta. Acta Obstet Gynecol Scand. 2007;86(2):210-7. [abstract]
12. French L; Prevention and treatment of postpartum endometritis. Curr Womens Health Rep. 2003 Aug;3(4):274-9. [abstract]
13. French LM, Smaill FM; Antibiotic regimens for endometritis after delivery. Cochrane Database Syst Rev. 2004 Oct 18;(4):CD001067. [abstract]

Acknowledgements