Chorioamnionitis

Inflammation of the amniochorionic (fetal) membranes of the placenta, typically in response to microbial invasion

Aetiology

  • Typically polymicrobial
  • Common organisms:
    • Ureaplasma urealyticum
    • Mycoplasma hominis
    • Escherichia coli
    • Group B Streptococcus
    • Anaerobes (Bacteroides, Gardnerella)
  • Less commonly:
    • Viral or fungal pathogens
  • Infection usually ascends from the cervicovaginal flora

Risk factors

Factors which introduce microbes to uterine cavity:
  • Invasive pre-natal diagnostics
  • Prolonged rupture of membranes
  • Prolonged labour
  • Repeat digital examinations in context of ruptured membranes
  • Nulliparity
  • Meconium stained liquour

Clinical presentation

  • Signs and symptoms include offensive PV loss, fetal CTG concerns, maternal pyrexia and abdominal pain

Investigations

  • The presence of fever between 38.0°C and 39.0°C alone is insufficient to indicate chorioamnionitis and is termed isolated maternal fever
  • When intrapartum (during delivery) fever is higher than 39.0°C, suspected diagnosis of chorioamnionitis can be made
  • Diagnosis is typically not confirmed until after delivery - histological sample of the fetal membranes or through amniotic testing

Management

  • Broad-spectrum antibiotics
  • Delivery - if not in established labour needs IOL or LUSCS
  • Subsequent increase in risk of post-partum haemorrhage - reduce with active 3rd stage syntocinon infusion
  • Avoid post-partum intra-uterine contraception (PPIUC)