chorioamnionitis
chorioamnionitis
[kor″e-o-am″ne-o-ni´tis]cho·ri·o·am·ni·o·ni·tis
(kō'rē-ō-am'nē-ō-nī'tis),chorioamnionitis
Obstetrics Infection of the amniotic sac and villi Clinic High fever, prolonged rupture of membranes, prematurity, and ↑ fetal M&Mcho·ri·o·am·ni·o·ni·tis
(kōr'ē-ō-am'nē-ō-nī'tis)Chorioamnionitis
| DRG Category: | 765 |
| Mean LOS: | 4.8 days |
| Description: | SURGICAL: Cesarean Section With CC or Major CC |
| DRG Category: | 775 |
| Mean LOS: | 2.4 days |
| Description: | MEDICAL: Vaginal Delivery Without Complicating Diagnoses |
Chorioamnionitis, or intra-amniotic infection (IAI), is an infection of the chorion, amnion, and amniotic fluids that surround the fetus and is characterized by monomorphonuclear and polymorphonuclear leukocytes invading the membranes. Leukocytes in the membranes are maternal in origin; leukocytes in the amniotic fluid (amnionitis) or in the umbilical cord (funisitis) are fetal in origin. Subsequently, the fetus also becomes infected. Chorioamnionitis, which can occur with subtle or acute signs and symptoms, can happen at any time during the prenatal or intrapartal period. It occurs in 0.5% to 10% of all pregnancies and 0.5% to 2% of term pregnancies, most commonly after premature rupture of the membranes. Chorioamnionitis can also cause premature rupture of the membranes and preterm labor. If left untreated, it can lead to maternal sepsis or fetal demise. In fact, chorioamnionitis is associated with a neonatal mortality rate of 1% to 4% for term infants and up to 10% for preterm infants.
The prognosis for the mother with chorioamnionitis is good. Once the baby is delivered, the source of infection is removed. Rarely does chorioamnionitis lead to septic shock. Occasionally, pelvic inflammatory disease can develop if the infection is not totally resolved. The prognosis for the infant varies depending on the degree of infection that is transmitted to the fetus. Occasionally, no signs of infection develop in the infant, but this is not typical. Another factor involved in the infant’s prognosis is prematurity; for the very premature infant, the risk of respiratory distress syndrome may be even greater than the risk of infection.
Causes
Chorioamnionitis is usually caused by bacteria that inhabit the genital tract. Less frequently, it can result from pathogens that cross over from the maternal circulation to the amniotic sac. Rarely, it is caused by the descent of pathogens from the abdominal cavity through the fallopian tubes. Commonly identified pathogens that contribute to chorioamnionitis are Escherichia coli, Streptococcus faecalis, Neisseria gonorrhea, group A and B streptococci, Chlamydia trachomatis, and Staphylococcus aureus.
Predisposing factors that contribute to chorioamnionitis include poor maternal nutritional status, history of drug abuse, history of multiple sexual partners, premature or prolonged rupture of membranes, sexually transmitted infections (STIs), the placement of a cerclage (ligature around the cervix to treat cervical incompetence during pregnancy), chorionic villi sampling, intrauterine transfusion, amniocentesis, mechanical cervical ripening for labor induction, and repeated vaginal examinations during labor.
Genetic considerations
Although it is not strictly a genetic problem, genetic variants in the cytokine tumor necrosis factor-α have been associated with an increased risk of chorioamnionitis and fetal morbidity.
Gender, ethnic/racial, and life span considerations
Chorioamnionitis can occur with any pregnancy regardless of the age of the mother. Pregnant teens may be more at risk because they have a high incidence of bacterial vaginosis, urogenital infections, and STIs. Ethnicity and race have no known effects on the risk for chorioamnionitis.
Global health considerations
Countries in North America and Western Europe have relatively similar incidence rates. Chorioamnionitis prevalence is higher in developing nations with high prevalence of HIV-infected women than in countries with low prevalence of HIV infections. In developing countries such as India and China, the prevalence of group B streptococci infections is lower than in developed Western countries for unknown reasons.
Assessment
History
Ask about the last menstrual period to determine the estimated date of delivery and the gestational age of the fetus. Inquire about any past history of vaginal infections or STIs. Question the patient about the presence of any perineal pain, burning, malaise, or chills. Ask the patient if she is feeling contractions or if she has noted any leakage of the amniotic fluid. If the amniotic sac has ruptured, determine the time it occurred, the color of the fluid, and if the patient noted any odor. Also consider any prenatal tests or procedures, such as placement of a cerclage, chorionic villi sampling, intrauterine transfusions, or amniocentesis, that can predispose the patient to developing an intrauterine infection.
Physical examination
While not all patients will have symptoms, they may experience signs of infection such as abdominal tenderness, malaise, fever, tachycardia, and foul vaginal discharge. Early clinical findings in patients with chorioamnionitis may be vague. IAI can be present with no symptoms, and subclinical IAI may be three times more common than IAI with clinical symptoms. Assess the patient’s vital signs; patients with chorioamnionitis often display an elevated pulse above 120 beats per minute and temperature above 100.4°F. Palpate all quadrants of the abdomen for tenderness, noting the maternal response during examination of each quadrant. Foul odor of the vaginal discharge, color change of amniotic fluid from clear to light yellow to green, and an increase in the purulence of vaginal drainage are all consistent with chorioamnionitis.
Often, preterm labor patients with undiagnosed chorioamnionitis have contractions that do not respond to routine treatments of intravenous hydration and tocolytic therapy. Evaluate the baseline fetal heart rate. Fetal tachycardia, a heart rate above 160 beats per minute; a decreased fetal heart rate, a heart rate below 110 beats per minute; or decreased variability may be present with chorioamnionitis.
Psychosocial
Increased anxiety is usually present with patients who are experiencing preterm labor, premature rupture of membranes (PROM), or a history of a cerclage placement. Assess the patient’s understanding of the situation and encourage the patient to express her fears. Also include an assessment of the patient’s social support and the response of significant others to the patient’s condition.
Diagnostic highlights
General Comments: Diagnosis may be difficult to establish early on because symptoms are vague. Examination of amniotic fluid is definitive.
| Test | Normal Result | Abnormality With Condition | Explanation |
|---|---|---|---|
| Amniocentesis or endocervical culture | No growth | Growth of infecting organism | Culturing the amniotic fluid will reveal the presence of a causative organism, allowing for appropriate choice of antibiotic therapy |
Other Tests: Complete blood count with differential, C-reactive protein, group B streptococcal screening, fetal ultrasound, urinalysis, postpartum histological examination of the placenta
Primary nursing diagnosis
Diagnosis
Infection related to microorganism invasion of sterile areasOutcomes
Risk controlInterventions
Medication management; Labor induction; Cesarean section carePlanning and implementation
Collaborative
medical.
The medical management of a patient diagnosed with chorioamnionitis is delivery of the infant, regardless of the gestational age. Thus, the current recommendation is to induce labor on all term patients presenting with PROM to decrease the incidence of chorioamnionitis. Delivery benefits the mother by emptying the uterus of all infected material. Once delivered, the infant can then receive the necessary antibiotic therapy and supportive care. Usually, spontaneous labor occurs because of the infection. If an adequate contraction pattern and progressive dilation of the cervix are not noted, contractions can be induced by oxytocin (Pitocin). Broad-spectrum antibiotics administered during labor cross the placenta and achieve peak levels in the fetal circulation within an hour after parenteral administration to the mother. Cesarean section is typically avoided because of the increased risk of spreading the infection; however, if the fetus is showing signs of distress, a cesarean section is performed. If the fetus is preterm, arrange for a neonatologist or pediatrician to speak with the patient before delivery; notification of the nursery is also important. Immediately after delivery, cultures of the placenta and baby are obtained, and the newborn is monitored carefully for signs and symptoms of infection.Pharmacologic highlights
| Medication or Drug Class | Dosage | Description | Rationale |
|---|---|---|---|
| Cefoxitin | Varies by drug and patient condition | Second-generation cephalosporin | Broad-spectrum antibiotics are effective against gram-positive, gram-negative, aerobic, and anaerobic organisms; are less toxic; and cross the placenta to help the fetus |
| Mezlocillin | Varies by drug and patient condition | Extended-spectrum antibiotics | Broad-spectrum antibiotics are effective against gram-positive, gram-negative, aerobic, and anaerobic organisms; are less toxic; and cross the placenta to help the fetus |
| Ticarcillin; piperacillin | Varies by drug and patient condition | Penicillin | Broad-spectrum antibiotics are effective against gram-positive, gram-negative, aerobic, and anaerobic organisms; are less toxic; and cross the placenta to help the fetus |
Other Drugs: Other antibiotics such as clindamycin, gentamycin, ampicillin, and penicillin may also be used. Most often combinations of antibiotics are used to treat chorioamnionitis.
Independent
Anticipatory guidance provided by the nurse is beneficial for the patient. Provide information about antibiotic therapy, procedures that occur during labor and delivery, and possible outcomes for the infant. Because the patient’s anxiety level is elevated, you may need to repeat information several times. Allow the patient to express her fears. Answer the questions of the significant others and take time to listen to their concerns as well.
Monitor the patient for signs of infection after delivery, including the mother’s lochia, fundal height, vital signs, and incisional healing. The patient with an intrauterine infection is at a higher risk for a postpartum hemorrhage than are her noninfected counterparts. Careful and frequent assessments for vaginal bleeding and firmness of the fundus are critical. If the fundus is “boggy,” massage the fundus until firm.
Evidence-Based Practice and Health Policy
Nasef, N., Shabaan, A.E., Schurr, P., Iaboni, D., Choudhury, J., Church, P., & Dunn, M.S. (2013). Effect of clinical and histological chorioamnionitis on the outcome of preterm infants. American Journal of Perinatology, 30(1), 59–68.
- Chorioamnionitis has significant implications for neonatal and maternal health and may have longer-term implications for child health.
- In one retrospective study among a sample of 274 preterm infants with a mean gestational age of 27 weeks (SD, ± 1.6 weeks), 47% were born to mothers with clinical or histological chorioamnionitis. Eighty-four percent of all the infants survived to discharge home, and there were no differences in mortality rates between mothers with and without chorioamnionitis.
- The presence of intraventricular hemorrhage was significantly higher among infants born to mothers with clinical (39%) and histological chorioamnionitis (27%) than mothers without chorioamnionitis (16%) (p < 0.05).
- Among the 180 infants available for follow-up at 18 months, children born to mothers with clinical chorioamnionitis had lower cognitive (88 ± 10), language (82 ± 12), and motor scores (89 ± 11) compared to the children born to mothers without chorioamnionitis (99 ± 13, 92 ± 15, 97 ± 13, respectively) (p < 0.05).
Documentation guidelines
- Maternal vital signs; fetal heart rate pattern; uterine activity; maternal response to antibiotics; color, odor, and consistency of vaginal discharge
- If the Patient is Delivered
- Maternal and infant vital signs; amount and odor of lochia; involution of uterus; assessment of episiotomy or abdominal incision
- Amount of the infant’s fluid intake and output, infant’s response to antibiotics, daily weight of the baby