Postpartum infections comprise a wide range of entities that can occur after vaginal and cesarean delivery or during breastfeeding. In addition to trauma sustained during the birth process or cesarean procedure, physiologic changes during pregnancy contribute to the development of postpartum infections.[1] The typical pain that many women feel in the immediate postpartum period also makes it difficult to discern postpartum infection from postpartum pain.
Postpartum patients are frequently discharged within a couple days following delivery. The short period of observation may not afford enough time to exclude evidence of infection prior to discharge from the hospital. In one study, 94% of postpartum infection cases were diagnosed after discharge from the hospital.[2] Postpartum fever is defined as a temperature greater than 38.0°C on any 2 of the first 10 days following delivery exclusive of the first 24 hours.[3] The presence of postpartum fever is generally accepted among clinicians as a sign of infection that must be determined and managed.
Local spread of colonized bacteria is the most common etiology for postpartum infection following vaginal delivery. Endometritis is the most common infection in the postpartum period. Other postpartum infections include (1) postsurgical wound infections, (2) perineal cellulitis, (3) mastitis, (4) respiratory complications from anesthesia, (5) retained products of conception, (6) urinary tract infections (UTIs), and (7) septic pelvic phlebitis. Wound infection is more common with cesarean delivery. (A review study by Haas et al indicated that cleansing the vagina with a povidone-iodine or chlorhexidine solution immediately prior to cesarean delivery decreases the risk for postoperative endometritis.[4] )
The Route of delivery is the single most important factor in the development of endometritis.[5] The risk of endometritis increases dramatically after cesarean delivery.[5, 6] However, there is some evidence that hospital readmission for management of postpartum endometritis occurs more often in those who delivered vaginally.[6]
Other risk factors include prolonged rupture of membranes, prolonged use of internal fetal monitoring, anemia, and lower socioeconomic status.[5]
Perioperative antibiotics have greatly decreased the incidence of endometritis.[5]
In most cases of endometritis, the bacteria responsible are those that normally reside in the bowel, vagina, perineum, and cervix.
The uterine cavity is usually sterile until the rupture of the amniotic sac. As a consequence of labor, delivery, and associated manipulations, anaerobic and aerobic bacteria can contaminate the uterus.
Most often, the etiologic organisms associated with perineal cellulitis and episiotomy site infections are Staphylococcus or Streptococcus species and gram-negative organisms, as in endometritis.
Vaginal secretions contain as many as 10 billion organisms per gram of fluid. Yet, infections develop in only 1% of patients who had vaginal tears or who underwent episiotomies.
Those who underwent cesarean delivery have a higher readmission rate for wound infection and complications than those who delivered vaginally.[7]
Increased risk of genital tract infections is related to the duration of labor (ie prolonged labor increases risk of infection), use of internal monitoring devices, and number of vaginal examinations.[8]
Genital tract infections are generally polymicrobial. Gram-positive cocci and Bacteroides and Clostridium species are the predominant anaerobic organisms involved. Escherichia coli and gram-positive cocci are commonly involved aerobes.
The most common organism reported in mastitis is Staphylococcus aureus. The organism usually comes from the breastfeeding infant's mouth or throat.
Thrombosis may occur. Numerous factors cause pregnant and postpartum women to be more susceptible to thrombosis. Pregnancy is known to induce a hypercoagulable state secondary to increased levels of clotting factors. Also, venous stasis occurs in the pelvic veins during pregnancy.
Although relatively rare, septic pelvic thrombosis is occasionally observed in the postpartum patient, who might have fever.
Bacteria most frequently found in UTIs are normal bowel flora, including E coli and Klebsiella, Proteus, and Enterobacter species.
Any form of invasive manipulation of the urethra (eg, Foley catheterization) increases the likelihood of a UTI.
The following increase the risk for postpartum infections:
In the aforementioned study by Bauer et al, of approximately 45 million hospitalizations for delivery between 1998 and 2008, medical conditions that were found to be independently associated with severe sepsis included congestive heart failure, chronic kidney disease, chronic liver disease, and systemic lupus erythematosus. An association with rescue cerclage was also found.[9]
In a study by Yokoe et al in 2001, 5.5% of vaginal deliveries and 7.4% of cesarean deliveries resulted in a postpartum infection.[2] The overall postpartum infection rate was 6.0%. Endometritis accounted for nearly half of the infections in patients following cesarean delivery (3.4% of cesarean deliveries). Mastitis and urinary tract infections together accounted for 5% of vaginal deliveries.[2]
A study by Bauer et al indicated that in the United States from 1998 to 2008, of approximately 45 million hospitalizations for delivery, sepsis was a complication in 1 out of every 3333 deliveries. The investigators also found that during the study period, the risk for severe sepsis (1:10,823 deliveries) and sepsis-related death (1:105,263 deliveries) increased.[9]
The risk of postpartum urinary tract infection is increased in the African American, Native American, and Hispanic populations.[10]
The prognosis for postpartum infections is good with prompt and appropriate therapy.
In most reviews, maternal death rates associated with infection range from 4-8%, or approximately 0.6 maternal deaths per 100,000 live births.
A pregnancy-related mortality surveillance by the Centers for Disease Control and Prevention indicated infection accounted for about 11.6% of all deaths following pregnancy that resulted in a live birth, stillbirth, or ectopic.[11]
Complications include the following:
The history and course of the delivery is important in the evaluation of postpartum patients. Obtain the following information:
Features of postpartum infection vary depending on the source and may include the following:
Focus the physical examination on identifying the source of fever and infection. A complete physical examination, including pelvic and breast examinations, is necessary. Potential findings are discussed below.
Endometritis may be characterized by lower abdominal tenderness on one or both sides of the abdomen, adnexal and parametrial tenderness elicited with bimanual examination, and temperature elevation (most commonly >38.3°C).
Some women have foul-smelling lochia without other evidence of infection. Some infections, most notably caused by group A beta-hemolytic streptococci, are frequently associated with scanty, odorless lochia.
Patients with wound infections, or episiotomy infections, have erythema, edema, tenderness out of proportion to expected postpartum pain, and discharge from the wound or episiotomy site.
Drainage from wound site should be differentiated from normal postpartum lochia and foul-smelling lochia, which may be suggestive of endometritis.
Patients with mastitis have very tender, engorged, erythematous breasts. Infection frequently is unilateral.
Patients with pyelonephritis or UTIs may have costovertebral angle tenderness, suprapubic tenderness, and an elevated temperature.
Evaluate for tachypnea, rales, crackles, rhonchi, and consolidation.
Patients with septic pelvic thrombophlebitis, although rare, may have palpable pelvic veins. These patients also have tachycardia that is out of proportion to the fever.
Laboratory studies are directed at elucidating the severity of illness as well as the etiology of the infection. Mild cases of mastitis usually do not require laboratory investigation. Wound infections and infections of the genital tract makes it more difficult to ascertain the extent of involvement.
Laboratory studies should include the following:
Pelvic ultrasonography may be helpful in detecting retained products of conception, pelvic abscess, or infected hematoma.
Contrast-enhanced CT or MRI are useful in establishing the diagnosis of septic pelvic thrombosis.[12]
In some cases, a contrast-enhanced CT examination of the abdomen and pelvis may be helpful if concurrent concern is present for other non-pregnancy–related abdominal/pelvic sources of the infection (eg, appendicitis, colitis).
The most important aspect of prehospital care in a postpartum patient with a suspected infection is to ensure adequate fluid volume and to prevent sepsis and shock. Provide aggressive fluid management, begin cardiac monitoring, and administer oxygen.
Emergency Department care is focused on identifying the source of the infection, followed by appropriate antimicrobial therapy and referral.
In most cases, initial antimicrobial treatment is a combination of an aminoglycoside and clindamycin. Alternatively, an aminoglycoside plus metronidazole with or without ampicillin may also be used.[13]
Mild cases of endometritis after vaginal delivery may be treated with oral antimicrobial agents (eg, doxycycline, clindamycin).
Moderate-to-severe cases, including those involving cesarean deliveries, should be treated with parenteral broad-spectrum antimicrobials.
A review of trials for antibiotic regimens for the treatment of endometritis by French and Smaill concluded that gentamicin in combination with clindamycin is appropriate for endometritis.[14] In an update of these findings, on the basis of a Cochrane review of 42 trials comprising more than 4200 patients, investigators confirmed combination therapy with gentamicin and clindamycin remains appropriate for treatment of endometritis.[15] The researchers also noted that the use of additional oral therapy has not been proven to be beneficial.
In general, the patient's condition rapidly improves after antibiotics are administered.
Drainage, debridement, and irrigation may be required. Broad-spectrum antibiotics should be administered.
The Academy of Breastfeeding Medicine recommends frequent and effective milk removal in managing mastitis (most important step) or fluid mobilization.[16] Supportive measures include rest, adequate fluids, and nutrition.[16] Also use local measures, such as ice packs, analgesics, and breast support.[13]
Administer a penicillinase-resistant antibiotic such as cephalexin, dicloxacillin or cloxacillin, or clindamycin in penicillin-allergic patients.[13]
The mother should be told to continue to breastfeed the baby.[16] Continued breastfeeding prevents breast engorgement and subsequent pain.
If a breast abscess is present, or breastfeeding is not possible, a breast pump should be used in lactating women.[13]
Mastitis could lead to abscess formation, which may require surgical drainage.
Administer fluids, if evidence of dehydration exists.
Appropriate antibiotics should be used. These typically are trimethoprim-sulfamethoxazole, nitrofurantoin, ciprofloxacin, levofloxacin, or ofloxacin.[17, 18, 19]
The above antibiotics (including fluoroquinolones) for UTI are considered safe by the American Academy of Pediatrics (AAP) for nursing infants, with no reported effects seen in infants who are breastfeeding.[17, 18]
Although the AAP considers fluoroquinolones to be safe for breastfeeding mothers, they also recommend that the safest drug should be prescribed.[17] Fluoroquinolones are excreted in breast milk with unknown absorption by the infant. The potential for pediatric cartilage and joint damage were extrapolated from juvenile animal studies.[20, 21] For this reason, fluoroquinolones should not be first-line therapy and temporary discontinuation of breastfeeding should be considered.[20, 22]
Trimethoprim-sulfamethoxazole and nitrofurantoin are to be avoided in mothers with breastfeeding infants with G-6-PD deficiency.[17, 18]
When possible, the medication should be taken just after the patient has breastfed the infant to minimize drug exposure.[17]
Fever and flank pain should raise suspicion for pyelonephritis, and inpatient hospital admission should be considered. Ampicillin and gentamicin may also be given to lactating mothers with no reported effects on breastfeeding infants.[17]
Broad-spectrum antibiotics should be administered. Initial choice of antibiotics should cover gram-positive, gram-negative, and anaerobic organisms. Ampicillin and gentamicin with metronidazole or clindamycin is a common regimen.[12, 13]
Anticoagulation may be used, and it should be noted that there exists no universal guideline or recommendation for anticoagulation therapy in septic pelvic thrombosis. Initial bolus of 60 units/kg (4000 units maximum) followed by 12 units/kg/h (maximum of 1000 units/h) is recommended.[5] The aPTT is monitored for 2-3 times the normal value.[12, 13]
Alternatively, low-molecular weight heparin may be used with a dose of 1 mg/kg.[12, 13]
Patients with early postpartum endometritis (especially after cesarean delivery) should be admitted, as should any patient with suspected septic pelvic vein thrombosis. Postsurgical wound infections may also require inpatient management, particularly if there is extensive involvement of surrounding soft tissues, intractable pain, and fever.
Obstetric consultation must be obtained in cases of endometritis, postsurgical wound infections and cellulitis, retained products of conception, and septic pelvic phlebitis. If an obstetrician/gynecologist is unavailable, seek consultation with a general surgeon.
All patients with a postpartum infection should undergo follow-up with an obstetrician.
For patient education resources, see Pregnancy Center as well as Postpartum Perineal Care.
A Cochrane review found that for the prevention of post-caesarean endometritis, there was no clear difference between irrigation and intravenous antibiotic prophylaxis, however further research is necessary.[23] Another Cochrane review reported that post uncomplicated vaginal birth, routine administration of antibiotics may reduce the risk of endometritis, however, further studies are also needed.[24]
Clinical guidelines on postpartum endometritis were released in March 2019 by the Collège National des Gynécologues et Obstétriciens Français (CNGOF) and Société de Pathologie Infectieuse de Langue Française (SPILF).[25]
Caesarean delivery is the most significant risk factor for postpartum endometritis, particularly if performed after labor has begun.
Symptoms of postpartum endometritis include abdominopelvic pain, hyperthermia, and abnormal lochia. Uterine mobilization pain confirms the diagnosis.
Preferred: The first-line antibiotic is amoxicillin-clavulanic acid 3-6 g/d (depending on weight) IV or PO.
Penicillin allergy: In patients with penicillin allergy, a combination of clindamycin 600 mg 4 times/day plus gentamicin 5 mg/kg once a day may be used (caution in breastfeeding women).
Duration: Treatment is administered until 48 hours of apyrexia and resolved pelvic pain. If fever or pelvic pains pain persists for more than 72 hours of antibiotic therapy, perform pelvic imaging to evaluate for placental retention, septic thrombophlebitis, deep abscess, or other surgical complications.
Septic thrombophlebitis, if present, should be treated with heparin therapy for 6 weeks or more if embolism or thrombotic risk factors are also present.
If possible, swab the vagina with iodinated polyvidone or chlorhexidine before caesarean delivery. In addition, extraction of the placenta must be spontaneous.
Antibiotics are the mainstay of treatment. Pain medications also are important, because patients often have discomfort. Patients with septic pelvic thrombophlebitis must undergo anticoagulation therapy, and they should receive broad-spectrum antibiotics.
Clinical Context: Second-generation cephalosporin indicated for gram-positive coccal and gram-negative rod infections. Infections caused by cephalosporin-resistant or penicillin-resistant gram-negative bacteria may respond to cefoxitin. Must be used with clindamycin or doxycycline and an aminoglycoside for the treatment of endometritis, for which it is a drug of choice. Particularly important in early postpartum (first 48 h) infections.
Clinical Context: Inhibits protein synthesis and thus bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. Must be used with other drugs for endometritis. Used often for outpatient therapy for late postpartum (48 h to 6 wk after delivery) treatment.
Clinical Context: Aminoglycoside antibiotic used for gram-negative bacterial coverage. Commonly used with an agent against gram-positive organisms in treatment of endometritis. Consider if penicillins or other less toxic drugs are contraindicated, when clinically indicated, and in mixed infections caused by susceptible staphylococci and gram-negative organisms. Dosing regimens are numerous and adjusted on the basis of CrCl and changes in volume of distribution. Gentamicin may be given IV/IM.
Clinical Context: Inhibits bacterial protein synthesis by inhibiting peptide chain initiation at the bacterial ribosome where it binds preferentially to the 50S ribosomal subunit, causing bacterial growth inhibition. Must be used with other drugs in the treatment of endometritis. Second drug of choice, after dicloxacillin, in postpartum mastitis.
Clinical Context: Bactericidal antibiotic that inhibits cell wall synthesis. Used in treatment of infections caused by penicillinase-producing staphylococci. Primary drug of choice used for postpartum mastitis to cover S aureus.
Clinical Context: Used with heparin and third-generation parenteral cephalosporin in the treatment of septic pelvic vein thrombophlebitis to cover streptococci and Bacteroides and Enterobacteriaceae species.
Clinical Context: First-generation cephalosporin used to cover S aureus in mastitis. Encourage the mother to continue breastfeeding to shorten duration of symptoms. Another DOC for postpartum mastitis.
Antibiotic coverage for Bacteroides, group B and A streptococci, Enterobacteriaceae organisms, and Chlamydia trachomatis in endometritis is suggested. Wound and episiotomy site infections require broad-spectrum antibiotics as well, because of the polymicrobial nature of the local flora. Consider coverage primarily for Staphylococcus aureus infection in postpartum mastitis.