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Intraamniotic Infection



Julie S. Moldenhauer

, MD, Children's Hospital of Philadelphia

Reviewed/Revised Jan 2024
Topic Resources

Intraamniotic infection is infection and resulting inflammation of the chorion, amnion, amniotic fluid, placenta, decidua, fetus, or a combination. Infection increases risk of obstetric complications and problems in the fetus and neonate. Symptoms include fever, uterine tenderness, foul-smelling amniotic fluid, purulent cervical discharge, and maternal or fetal tachycardia. Diagnosis is by specific clinical criteria or, for subclinical infection, analysis of amniotic fluid. Treatment includes broad-spectrum antibiotics, antipyretics, and delivery.

Intraamniotic infection typically results from an infection that ascends through the genital tract and is often polymicrobial. Listeria monocytogenes, a cause of listeriosis, causes hematogenous intraamniotic infection.

Risk factors


Intraamniotic infection can cause as well as result from preterm PROM or preterm labor.

Fetal or neonatal complications include increased risk of the following:

Maternal complications include increased risk of the following:

Symptoms and Signs of Intraamniotic Infection

Intraamniotic infection typically causes fever. Other findings include maternal tachycardia, fetal tachycardia, uterine tenderness, foul-smelling amniotic fluid, and/or purulent cervical discharge. However, infection may not cause typical symptoms (ie, subclinical infection).

Diagnosis of Intraamniotic Infection

  • Maternal fever during labor without other identifiable cause

  • Amniocentesis for suspected subclinical infection

  • Isolated maternal fever: A single oral temperature of ≥ 39° C or an oral temperature of 38 to 38.9° C that is still present when the temperature is measured again after 30 minutes (isolated maternal fever does not automatically lead to a diagnosis of infection)

  • Suspected intraamniotic infection: Maternal fever and one or more of the following: elevated maternal white blood cell [WBC] count, fetal tachycardia, or purulent cervical discharge

  • Confirmed intraamniotic infection: Sometimes further evaluation is indicated to confirm intraamniotic infection by amniotic fluid tests Subclinical infection (Gram staining, culture, glucose level) or histologic evidence of placental infection or inflammation

Presence of a single symptom or sign, which may have other causes, is less reliable. For example, fetal tachycardia may be due to fetal distress for other reasons, eg, medications, cocaine, or maternal hyperthyroidism.

Subclinical infection

Refractory preterm labor (persisting despite tocolysis) may suggest subclinical infection. If membranes rupture prematurely before term, clinicians should consider subclinical infection to determine whether induction of labor is indicated.

Amniocentesis with culture of amniotic fluid can help diagnose subclinical infection. The following fluid findings suggest infection:

  • Presence of bacteria or leukocytes using Gram staining

  • Glucose level < 14 mg/dL

  • WBC count > 30 cells/mcL

  • Trace or greater leukocyte esterase activity (tested with urine dipstick reagent strip)

  • Positive culture

Other diagnostic tests for subclinical infection are under study.

Diagnosis reference

Treatment of Intraamniotic Infection

  • Broad-spectrum antibiotics covering gram positives, gram negatives, and anaerobes

  • Antipyretics

  • Delivery as indicated

Treatment of intraamniotic infection is recommended when

  • Intraamniotic infection is suspected or confirmed.

  • Women in labor have an isolated temperature of ≥ 39° C and no other clinical risk factors for fever.

If women have a temperature of 38 to 39° C and no risk factors for fever, treatment can be considered.

Appropriate antibiotic treatment reduces morbidity in the mother and neonate.

As soon as intraamniotic infection is diagnosed, it is treated with broad-spectrum IV antibiotics and delivery (see table ).


A typical intrapartum antibiotic regimen (for a patient with no allergy to penicillin) consists of both of the following:

  • Ampicillin 2 g IV every 6 hours AND

  • Gentamicin 2 mg/kg IV (loading dose) followed by 1.5 mg/kg IV every 8 hours OR gentamicin 5 mg/kg IV every 24 hours

Antibiotics should not automatically be continued after delivery; use should be based on clinical findings (eg, bacteremia, prolonged fever) and on risk factors for postpartum endometritis, regardless of the delivery route.

The risk of postpartum endometritis and pelvic infection is higher after cesarean versus vaginal delivery. After cesarean delivery, patients with intraamniotic infection should receive one additional dose of the intrapartum antibiotic regimen plus anaerobic coverage; a dose of clindamycin 900 mg IV OR metronidazole 500 mg IV is given after the umbilical cord is clamped.

Antipyretics, preferably acetaminophen before delivery, should be given in addition to antibiotics. Antipyretics to manage fevers may improve fetal status during labor, based on fetal monitoring (1 Treatment reference Intraamniotic infection is infection and resulting inflammation of the chorion, amnion, amniotic fluid, placenta, decidua, fetus, or a combination. Infection increases risk of obstetric complications... read more ).

Intraamniotic infection alone is rarely an indication for cesarean delivery. Informing the neonatal care team when intraamniotic infection is suspected or confirmed and which risk factors are present is essential to optimize evaluation and treatment of the neonate.

Treatment reference

Prevention of Intraamniotic Infection

Risk of intraamniotic infection is decreased by avoiding or minimizing digital pelvic examinations in women with preterm PROM Prelabor Rupture of Membranes (PROM) Prelabor rupture of membranes is leakage of amniotic fluid before onset of labor. Diagnosis is clinical. Delivery is recommended when gestational age is ≥ 34 weeks and is generally indicated... read more . Broad-spectrum antibiotics are given to women with preterm PROM to prolong latency until delivery and decrease risk of infant morbidity and mortality.

Universal screening for group B streptococcus should be performed at 35 to 37 weeks gestation for all pregnant patients, and patients who screen positive should be given antibiotic prophylaxis during labor.

Key Points

  • Intraamniotic infection is infection of the chorion, amnion, amniotic fluid, placenta, or a combination that increases risk of obstetric complications and problems in the fetus and neonate.

  • Consider the diagnosis when women have the classic symptoms of infection (eg, fever, purulent cervical discharge, uterine pain or tenderness) or when fetal or maternal tachycardia or refractory preterm labor is present.

  • Determine the white blood cell count, and consider analyzing and culturing amniotic fluid if women have refractory preterm labor or preterm PROM.

  • Treat suspected or confirmed intraamniotic infection with broad-spectrum antibiotics, antipyretics, and delivery.

  • Also treat women in labor if they have an isolated temperature of ≥ 39° C and no other clinical risk factors for fever.

Drugs Mentioned In This Article

Drug Name Select Trade
Garamycin, Genoptic, Genoptic SOP, Gentacidin, Gentafair, Gentak , Gentasol, Ocu-Mycin
Cleocin, Cleocin Ovules, Cleocin Pediatric, Cleocin T, CLIN, Clindacin ETZ, Clindacin PAC, Clindacin-P, Clinda-Derm , Clindagel, ClindaMax, ClindaReach, Clindesse, Clindets, Evoclin, PledgaClin, XACIATO
Flagyl, Flagyl ER, Flagyl RTU, LIKMEZ, MetroCream, MetroGel, MetroGel Vaginal, MetroLotion, Noritate, NUVESSA, Nydamax, Rosadan, Rozex, Vandazole, Vitazol
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Aphen, Apra, Children's Acetaminophen, Children's Pain & Fever , Children's Pain Relief, Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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