Infections in Pregnancy

Urinary Tract Infections/Pyelonephritis

Epidemiology:

• Occurs in as many as 15% of pregnant women and between 20-40% of pregnant women with asymptomatic bacteriuria will progress to pyelonephritis (Gorgas 2008)

Management:

• Uncomplicated UTI
  • Suggested antibiotics include:
    • Nitrofurantoin 100mg PO BID x7 days OR
    • Cephalexin 500mg PO BID x7 days
  • Pyelonephritis
    • Hospital admission
    • Suggested antibiotics include:
      • Ceftriaxone 1g IV Q24H OR
      • Aztreonam 2g IV Q8H for beta-lactam allergy

Complications:

• Maternal sepsis
• Maternal renal injury
• Congenital abnormalities of the fetus
• Premature rupture of membranes
• Low birth weight

Chorioamnionitis

Definition: Also known as intraamniotic infection. Chorioamnionitis is a bacterial infection of fetal amnion and chorion membranes.

Epidemiology

• Occurs in 1 to 10% of all pregnancies (Gorgas 2008)
• Incidence increases significantly with preterm labor

Diagnosis

• Chorioamnionitis is defined as maternal fever >38°C and at least two of the following (Apantaku and Mulik 2007):
  • Maternal tachycardia >100 beats/min for five minutes
  • Fetal tachycardia >160 beats/min for five minutes
  • Purulent or foul-smelling amniotic fluid or vaginal discharge
  • Uterine tenderness
  • Maternal leukocytosis

Evaluation (Abbrescia 2003)

• CBC
• Blood cultures
• Vaginal fluid for phosphatidylglycerol
  • Tests for fetal lung maturity
• Cervical AND vaginal cultures
• Physical Exam
  • Avoid digital cervical exam
  • Speculum exam should be done with sterile speculum
• Ultrasonography for fetal well being

Management

• Given concern for neonatal sepsis, patients should be admitted for IV antibiotics, supportive cares, and possible early delivery
• Most commonly an ascending infection from normal vaginal flora, so antibiotics must be chosen to cover polymicrobial infections
• Ampicillin IV 2g Q6H AND Gentamicin IV 1.5mg/kg Q8H
  • In PCN allergic patient substitute vancomycin 1 g IV Q12H for ampicillin
• Can only be considered cured with delivery of infected products of conception

Complications

• Placental abruption
• Premature birth
• Neonatal sepsis
• Neonatal death
• Cerebral palsy
• Maternal sepsis
• Need for cesarean delivery
• Postpartum hemorrhage

Postpartum Endometritis

Definition: Generalized uterine infection

Epidemiology

• Sepsis results in 15% of maternal deaths worldwide (Houry 2014)
• More common in surgical than vaginal deliveries
• May co-exist with surgical site infection

Diagnosis

• Classic triad includes: fever, lower abdominal pain and uterine tenderness, and foul smelling lochia

Management

• Hospital admission
• Cover for polymicrobial infection, including anaerobes
  • Clindamycin 900 mg IV Q8H AND Gentamicin 5-7 mg/kg IV Q24H

Septic Abortion

Epidemiology:

• The World Health Organization estimates that one in eight pregnancy related deaths worldwide can be directly attributed to unsafe abortion procedures (Gorgas 2008)

Diagnosis:

• Clinical presentation includes fever, abdominal pain and uterine tenderness in setting of recent abortion
• Presentation can vary from mild infection to septic shock

Evaluation:

• Lactate
• Cultures of cervix, blood and urine
• Coagulation panel to screen for DIC
• Abdominal X-ray to evaluate for free air or retained surgical foreign bodies
• Pelvic ultrasound to evaluate for retained products of conception or surgical foreign bodies

Management:

• Hospital admission may be indicated as infection can progress to septic shock, organ failure, DIC and cardiovascular collapse
• Broad-spectrum antibiotics are indicated. Triple antibiotic coverage is recommended. Suggested regimens include:
  • Ampicillin AND
  • Gentamicin AND
  • Clindamycin OR Metronidazole
• Update tetanus vaccination
• Usually requires dilation and curettage to remove any retained products of conception or foreign bodies.

References:

Abbrescia, K. and B. Sheridan (2003). “Complications of second and third trimester pregnancies.” Emerg Med Clin North Am 21(3): 695-710, vii. PMID: 12962354

Apantaku, O. and V. Mulik (2007). “Maternal intra-partum fever.” J Obstet Gynaecol 27(1): 12-15. PMID: 17365450

Desai, S. and S. Henderson. Labor and Delivery and Their Complications. In: Marx, J et al, ed. Rosen’s Emergency Medicine. 8^th ed. Philadelphia, PA: Elsevier Saunders; 2014:2331-2350.

Gorgas, D. L. (2008). “Infections related to pregnancy.” Emerg Med Clin North Am 26(2): 345-366, viii. PMID: 18406978

Houry, D and B. Salhi. Acute Complications of Pregnancy. In: Marx, J et al, ed. Rosen’s Emergency Medicine. 8^th ed. Philadelphia, PA: Elsevier Saunders; 2014: 2282-2299.