Intraamniotic infection - Corioamnionitis

Intrauterine infection, chorioamnionitis or triple I is an infection of the placental membranes and amniotic contents (fluid, cord and foetus).

It occurs in 4% of term deliveries and 8-50% of preterm deliveries.

The cause is usually an infection originating in the lower genitourinary tract (cervical and vaginal area), which migrates upwards to the amniotic cavity. It is associated with preterm labour, premature rupture of membranes and prolonged labour.

Suspicion of this entity exists when maternal fever (temperature above 38°C) and one of the following appear:

• Purulent cervical discharge
• Foetal tachycardia (160 beats/min)
• Elevated leukocytes in the blood (above 15,000).

Diagnosis is confirmed by amniocentesis, and/or endocervical, vaginal or rectal cultures.

Treatment is based on antibiotics, antipyretics and termination of pregnancy. Below 34 weeks gestation, corticosteroids will be administered to mature the lungs of the foetus, and below 32 weeks magnesium sulphate, to protect the nervous system of the foetus.

It increases the risk of complications for the foetus and the mother. At the foetal level, it increases the risk of retinopathy, bronchopulmonary dysplasia, respiratory distress syndrome, neonatal sepsis, intracranial haemorrhage and neurodevelopmental impairment. At the maternal level, there is an increased risk of postpartum haemorrhage, uterine rupture, hysterectomy, endometritis, sepsis and maternal mortality.