Puerperal Infection
last authored: Dec 2010, Glenn Patriquin
last reviewed: Jan 2012, Daisy Dharmaraj
Introduction
Puerperal infection (also known as childbed fever) is a global leading cause of maternal death. Termed in 1937 'the arch-foe of motherhood' by Ross Mitchell, over 6 million cases yearly lead to at least 77,000 maternal deaths worldwide, most of which occur in low-resource countries (AbouZahr, 2003).
Puerperal fever is diagnosed upon recording an oral temperature of 38.0 degrees C (100.4 degrees F) or more for any two of the first ten days subsequent to childbirth or abortion. While the vast majority of these are due to infection of the genital tract, fever has many other potential causes, as described below. Puerperal sepsis is defined by the World Health Organization as a genital tract infection occurring between the rupture of membranes and the 42nd day postpartum, coinciding with fever. One of pelvic pain, abnormal vaginal discharge, abnormal odour or discharge, or a delay in the reduction of uterine size must also be present.
Rates of puerperal fever were critical to the realization that health care providers could transmit infection, and that proper hand-washing could dramatically impact rates of illness and death, as discovered by Dr Semmelweis in Austria in the 1840's (Mitchell, 1937). This discovery began a transformation in health care - one that continues today, as nosocomial infections continue to plague patients and hospitals.
The Case of Martha S.
A 25 year old woman (G1P1) presents to your clinic eight days postpartum, complaining of a temperature of at least 38.5 degrees Celsius over the past 3 days, and a foul-smelling vaginal discharge. She is in otherwise good health, and her baby, who was born by emergency Caesarian section in a rural clinic, is doing well. Physical examination of your patient reveals an oral temperature of 38.6 degrees Celsius, a clean and non-weeping abdominal wound, and pain of palpation of her uterus.
- What is the differential diagnosis of the site of infection?
- What was most likely the source of this infection?
- What features of your patient’s history and delivery put her at higher risk for puerperal infection?
Causes and Risk Factors
As described, puerperal infections are mostly due to endometritis, but can also be due to wound infections (from Caesarean section or episiotomy), mastitis, urinary tract infections, respiratory infections, or septic thrombophlebitis.
Classically, Group A streptococcus causes severe cases of puerperal infections, however endometritis is now more commonly caused by group B hemolytic streptococcus, gonococci, Chlamydia, herpes simplex virus, and genital mycoplasma.
Endometritis is often a polymicrobial disease, with aerobes and anaerobes represented.
Mastitis is most often caused by Staphylococcus aureus, Group A or B streptococci, or Hemophilus spp.
UTIs are caused by microorganisms that typically infect the urinary tract of non-pregnant women, mainly Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae.
Risk factors for puerperal infection include:
- Caesarian section
- birth in non-hygienic conditions
- low socioeconomic status
- poor nutrition, anemia
- first birth
- prolonged membrane rupture, or prolonged labour
- multiple pelvic exams during labour
- instrumentation during delivery
- retention of placental fragments in the uterus
- postpartum hemorrhage
Pathophysiology
The disease is based on an infection of the uro-genital tract, pelvis, incisions, or breast tissue following delivery, and the possible subsequent hematological infection or sepsis. Puerperal infection following vaginal delivery primarily involves the placental implantation site and adjacent myometrium or lacerations in the cervix or vagina. In caesarean sections it is that of an infected surgical incision. Bacteria that colonise the cervix and vagina gain access to amniotic fluid during labour and post partum invade devitalised uterine tissue.
The sources of infection are typically divided into three groups:
- nosocomial (organisms acquired within the hospital or due to the patient’s own flora)
- exogenous (contamination from external sources, such as unhygienic instruments, and unhygienic practices),
- endogenous (a mixed population of genital tract flora).
Signs and Symptoms
- history
- physical exam
History
Possible findings on history (depending on site of infection):
- fever (may be the only symptom)
- pelvic, abdominal, or flank pain
- Abnormal vaginal discharge
- Foul-smelling vaginal discharge
- Respiratory symptoms (cough, pleuritic chest pain, dyspnea)
- Breast engorgement
If it is due to respiratory infection the patient may have
- cough
- pleuritic chest pain
- difficulty in breathing /dyspnea)
Fever due to mastitits or breast abscess may have
- swelling of the breast
- pain on touching
- redness
Urinary infection usually presents as:
- pain with passing urine (dysuria)
- lower abdominal pain
- fever with chills
- occasionally blood stained urine
If it is due to thrombophlebitis the patient may complain of
- pain in the limb
- engorged veins
- deep vein thrombosis
- symptoms may not be found
Physical Exam
Possible physical findings (depending on the site of infection)
Uterine/wound
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Breasts
Respiratory
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Major signs of puerperal sepsis:
Classical signs:
- Tachycardia
- Tachypnea
- Cervical motion tenderness
Intermediate signs:
- Fever
- Pain
- Suprapubic tenderness
- Ileus
- Foul discharge
Rare signs:
- Oliguria
- Edema
- Shock
- Jaundice
- Mental suppression
Signs that suggest a critical illness:
- Increased sympathetic activity (tachycardia, hypertension, pallor, clamminess, and peripheral shutdown)
- Systemic inflammation (fever or hypothermia, tachycardia, tachypnea)
- Organ hypoperfusion (cold peripheries, hypoxemia, confusion, hypotension, and oliguria)
- Biochemical (metabolic acidosis, leukocytosis or leukopenia, thrombocytopenia, elevated urea, elevated creatinine, and elevated C-reactive protein)
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
In spite of the microbial nature of the disease, the diagnosis of endometritis is commonly one made clinically. Though Gram stains and cultures may play a role in expediting and confirming a diagnosis, the difficulty in obtaining samples that are not contaminated by cervicovaginal flora limit their usefulness.
Helpful tests include:
- blood cultures
- white blood cell count (may show leukocytosis)
- ESR
- urine culture and microscopy
In the case of wound infections or mastitis, swabs of the wound or Gram stain of the drainage or of the breast milk may reveal the causative agent or leukocytes, indicative of infection.
Diagnostic Imaging
Diagnostic imaging is not generally indicated for endometritis, though the diagnostic usefulness of ultrasound, CT, and magnetic resonance angiography are subjects of research.
If you are concerned about retained placenta, an ultrasound can be helpful.
Ultrasound and CT however can be used in cases of pelvic abscesses (and cases of episiotomy infections where abscesses are suspected) however, as they can demonstrate fluid/gas interfaces within the affected tissue.
Doppler will be helpful in diagnosing thrombophlebitis.
Differential Diagnosis
As discussed, fever in the postpartum period can be caused by many conditions:
- endometritis
- mastitis
- wound infections (from cesarean section or episiotomy)
- urinary tract infections
- respiratory infection
- septic thrombophlebitis
Prevention
A number of steps can be taken to reduce the chances of developing puerperal fever:
- hygiene during delivery
- avoid frequent pelvic examination
- avoid unnecessary catheterisation of the bladder
- in situations of premature rupture of membranes, provision of prophylactic antibiotics
- antimicrobial prophylaxis at the time of Caesarean section
- ensure swab count before closing the skin in Caesarean section
- treatment of bacterial vaginitis
- treatment of respiratory infections before/during delivery/surgery- depending on the presenting problem and time of admission
- operative technique like allowing the placenta to separate rather than separating it manually
Treatments
If the woman is unwell, she should be admitted and agressively treated. If symptoms of shock are present, provide oxyen and IV fluids.
The treatment of the main cause of puerperal infection, endometritis, is based on the assumption of a polymicrobial infection. An aminoglycoside (for Gram negative coverage) and clindamycin (for Gram positive and anaerobic coverage) are often used. Another possible treatment regimen includes the combination of a cephalosporin (second or third generation) plus clindamycin or high dose metronidazole.
Many doctors will routinely perform a D&C to ensure there are no retained placental fragments.
In the case of wound infections, Gram staining and culturing of the wound drainage are performed and antibiotic choices are determined based on their findings. In some cases, surgical removal of infected tissue is undertaken, especially in rare cases of necrotizing fasciitis.
The treatment of mastitis includes the use of penicillinase-resistant antibiotics, applying ice packs and topical analgesics.
Consequences and Course
The course of the illness and complications may include septicemia, endotoxic shock, peritonitis, and abscess formation, often requiring surgery. These can be life-threatening Puerperal infection may also lead to compromised fertility. Effects on the fetus may include depressed Apgar scores, neonatal septicemia, and pneumonia. These too can lead to mortality.
Resources and References
AbouZahr C. 2003. Global burden of maternal death and disability. British Medical Bulletin 67(1):1-11.
Maharaj, Dushyant. 2007. Puerperal pyrexia: a review. Part I. Obstetrical and Gynecological Survey 62:393-399.
Maharaj, Dushyant. 2007. Puerperal pyrexia: a review. Part II. Obstetrical and Gynecological Survey 62:400-406.
Mitchell R. 1937. Puerperal Infection. CMAJ. 599-603.
William’s obstetrics 23rd edition Cunningham Leveno Bloom Hauth Rouse Spong
Topic Development
authors: Glenn Patriquin
reviewers: Daisy
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