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

Aetiology

• 96% caused by ascending infection and usually polymicrobial from E. coli, mycoplasma, anaerobes and group B strep

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 features

• Signs and symptoms include offensive PV loss, foetal 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 foetal membranes or through amniotic testing

Management

• Broad-spectrum antibiotics
• Delivery - if not in established labour needs IOL or LUSCS