Chorioamnionitis and PPROM

chorioamnionitis

What it is Chorioamnionitis?

It is inflammation of the chorion and amnion. It happens due to the bacterial infections to the amniotic fluid, fetal membrane, placenta and/or uterus. It is now believed that chorioamnionitis is a cause of preterm premature rupture of membranes (PPROM) and/or preterm labor (PTL)

How it happened?

The most common route of intrauterine infection is ascending bacteria from the lower genital tract. This occurs most commonly in the presence of rupture of membranes, but is also possible with intact membranes. Chorioamnionitis is usually polymicrobial and in a majority of cases is caused by a combination of anaerobic and aerobic organisms.

Common pathogens involve in genital tract infections are:
1. Gardnerella vaginalis
2. Ureaplasma urealyticum
3. Bacteroides bivius
4. group A, B, and D streptococci
5. Escherichia coli

Other routes of infection include hematogenous (blood borne) or transplacental infection, retrograde infection from the pelvis, and transuterine infection caused by medical procedures, such as amniocentesis and chorionic villus sampling (CVS)

Once they have colonized the uterine cavity, bacteria can not only infect the fetus but also can release endotoxins. The bacterial endotoxins trigger a release of cytokines in maternal and fetal tissue that leads to a release of additional cytokines, leukocyte migration, and then prostaglandin release from the myometrium and fetal membranes.This prostaglandin release, which can lead to rupture of the fetal membranes and/or to the initiation of uterine contractions, is believed to be the mechanism (or one of the mechanisms) of preterm premature rupture of membranes and preterm labor.

risk factors

1. premature labor
2. prolonged rupture of membranes
3. digital vaginal exam
4. fetal scalp electrodes
5. urogenital infections
6. maternal chronic disease, maternal nutritional status, and emotional stress
   

Diagnosis

1. presence of maternal fever of more than 38°C (100.4°F)
2. maternal tachycardia (≥100-120 bpm)
3. fetal tachycardia (≥160 bpm)
4. uterine tenderness
5. purulent or foul-smelling amniotic fluid
6. maternal leukocytosis (>15,000-18,000 cells/mm)

maternal complications

1. bacteremia
2. labor abnormalities
3. increased need for oxytocin
4. increased risk of cesarean birth.
5. increases the risk of postpartum hemorrhage
6. postpartum endometritis

Fetal/Neonatal Complications

1. sepsis
2. pneumonia
3. respiratory distress
4. death

treatment

1. Intrapartum antibiotic therapy
2. Intrapartum antipyretic administration

references:http://www.medscape.com/viewarticle/573988_print