Chorioamnionitis
Management
1. antibiotics 2. route of delivery - expedited birth not warranted but increase risk for developing neonatal infection the longer the labour continues 3. fetal monitoring during labour 4. antipyretics IAI cannot be cured without delivery. Induction or augmentation of labour warranted as appropriate, with CS reserved for standard obstetrical indications.
Clinical findings
1. fever 38C or greater (100%) 2. uterine tenderness (4-25%) 3. maternal tachycardia (>100/min) (50-80%) 4. fetal tachycardia (>160/min) (40-70%) 5. purulent or foul amniotic fluid (4-25%) 6. Maternal leukocytosis (70-90%) 7. Bacteremia (5-10% overall but most common when IAI is associated with GBS or E.coli)
Differential diagnosis
1. labour 2. abruption 3. extrauterine infections (i.e. pyelonephritis, influenza, appendicitis, pneumonia)
Adverse outcomes for fetus/neonate
1. perinatal death 2. asphyxia 3. early onset neonatal sepsis 4. septic shock 5. pneumonia 6. meningitis 7. intraventricular hemorrhage 8. cerebral white matter damage 9. long-term disability including CP 10. morbidity related to preterm birth
Risk factors (9)
1. prolonged labour 2. prolonged ROM 3. multiple digital VE 4. nulliparity 5. previous IAI 6. MSAF 7. internal fetal or uterine monitoring 8. presence of genital tract pathogens (i.e. STI, GBS, BV) 9. alcohol and tobacco use
Incidence
IAI associated with 20-40% of early neonatal sepsis and pneumonia Highest at preterm deliveries and decreases as pregnancy advances toward term
Adverse effects of clinical course
IAI associated with increased risks of: 1. labour abnormalities 2. uterine atony 3. PPH 4. endometritis
Etiology
IAI usually results from migration of cervicovaginal flora (polymicrobial) through the cervical canal to infect the fetal membranes, placenta, amniotic fluid, and fetus. Rupture of membranes can facilitate this process Less likely, infection can occur transplacentally from bacteremia, or the amniotic fluid/placenta is inoculated with bacteria during invasive procedures in utero (i.e. amnio)
Intraamniotic infection (IAI) AKA chorioamnionitis amnionitis amniotic fluid infection
infection of the amniotic fluid, membranes, placenta and/or decidua
