Chorioamnionitis (Intraamniotic Infection, IAI)

Recognize the diagnosis - Fever of at least 39 C, or 38-39 C sustained over 30 minutes plus one of maternal tachycardia, fetal tachycardia, uterine tenderness, foul-smelling vaginal discharge, or leukocytosis. The WBC count has low sensitivity and specificity and cervical cultures do not correlate with intraamniotic infection, so a normal white count does not clear her.

Neuraxial after antibiotics are working - Systemic infection is a relative, not absolute, contraindication to an epidural technique, on two grounds: the theoretical risk of seeding the epidural space, and vasodilation adding hemodynamic instability. Neuraxial techniques are safe once the patient has demonstrated a response to antibiotic therapy - so get ampicillin and gentamicin started (clindamycin, cefazolin, or vancomycin for penicillin allergy) and site the block after.

Expect an exaggerated drop with the block - Fever, vasodilation, and poor oral intake leave her relatively hypovolemic, so the sympathectomy from a spinal or an epidural bolus can drop pressure hard. Have a vasopressor drawn up before you dose, not after.

Plan for postpartum hemorrhage - Chorioamnionitis is an established risk factor for uterine atony and puts her at medium risk for postpartum hemorrhage, which earns a type and screen up front. Two medium-risk factors together - chorioamnionitis plus prolonged second stage, prolonged oxytocin, or a magnesium infusion - moves her to high risk and a type and cross.

Reconcile the maternal tachycardia - Maternal and fetal tachycardia are diagnostic features of the infection itself, so a heart rate of 130 after delivery is not automatically hemorrhage. Check it against uterine tone, measured blood loss, and blood pressure before you treat the number.

Term labor here often ends in the OR - Term deliveries complicated by chorioamnionitis are associated with failure to progress. A labor epidural in this patient has a real chance of becoming the cesarean anesthetic, so site it well and keep it working.

Cesarean adds a dose, vaginal does not - Current practice is one additional dose of antibiotic after cesarean delivery and no further antibiotics after vaginal delivery, with broader coverage if she deteriorates. Endometritis still follows in up to a third of women who deliver by cesarean with chorioamnionitis, and postpartum antibiotics do not reduce that.

Escalate if she is septic - Maternal complications include severe pelvic infection, wound infection, postpartum hemorrhage, operative delivery, and maternal sepsis. If pressure is not responding to fluid and antibiotics, treat it as sepsis and support her hemodynamically toward delivery rather than waiting the labor out.

Brief the neonatal team - Neonatal risks include preterm birth, respiratory distress syndrome, bronchopulmonary dysplasia, neonatal sepsis, and neurologic injury. Someone who can resuscitate the baby should be in the room at delivery.

Chorioamnionitis is infection and inflammation of the chorion, amnion, and amniotic fluid, almost always ascending from the lower genital tract once membranes rupture. Usual organisms are group B streptococcus, Ureaplasma urealyticum, Mycoplasma hominis, Escherichia coli, Gardnerella vaginalis, and Bacteroides; Listeria can seed hematogenously through intact membranes. Risk rises with preterm or prolonged rupture, prolonged labor, repeated vaginal exams, internal monitoring, meconium-stained fluid, and nulliparity. It complicates about 4% of term deliveries and is found in over 90% of births at 21-24 weeks.

What matters at the board is the downstream physiology: a febrile, tachycardic, often volume-depleted mother who can progress to sepsis, a uterus that contracts poorly afterward, a term labor that stalls and heads to cesarean, and a neonate at risk for sepsis and prematurity.