Current management and long-term outcomes following chorioamnionitis

Abstract

Chorioamnionitis is the process of active infection within the amniotic cavity that induces an inflammatory response. A wide variety of pathologic organisms can cause chorioamnionitis. Prompt diagnosis and timely treatment with broad-spectrum antibiotics can help avert the significant short-term and long-term consequences that may result. This review aims to summarize the up-to-date diagnosis criteria, treatment protocols, and long-term sequelae of missed diagnoses or poorly treated disease. It also calls for future studies that aim to better understand the mechanism of disease and to develop better detection and intervention methods to prevent the significant associated morbidity.

Keywords: Chorioamnionitis; Endometritis; Fetal infection; Fetal inflammation; Funisitis; Neonatal sepsis; Perinatal infection; Perinatal inflammation.

Figure 1

A diagram exhibiting the relationship between different diagnostic criteria of chorioamnionitis and neonatal outcomes.

Figure 2

Incidence of early- and late-onset invasive group B streptococcal (GBS) disease --- Active Bacterial Core surveillance areas, 1990--2008, and activities for prevention of GBS disease. The United States and Western Europe are similar in terms of their prevalence of GBS. From Verani JR, McGee L, Schrag SJ. Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010. MMWR Recomm Rep. Nov 19 2010;59(RR-10):1-36; with permission.

Figure 3

Algorithm for screening for group B streptococcal (GBS) colonization and use of intrapartum prophylaxis for women with preterm* labor (PTL). * At <37 weeks and 0 days' gestation. ^† If patient has undergone vaginal-rectal GBS culture within the preceding 5 weeks, the results of that culture should guide management. GBS-colonized women should receive intrapartum antibiotic prophylaxis. No antibiotics are indicated for GBS prophylaxis if a vaginal-rectal screen within 5 weeks was negative. ^§ See Figure 4 for recommended antibiotic regimens. ^¶ Patient should be regularly assessed for progression to true labor; if the patient is considered not to be in true labor, discontinue GBS prophylaxis. ** If GBS culture results become available prior to delivery and are negative, then discontinue GBS prophylaxis. ^†† Unless subsequent GBS culture prior to delivery is positive. ^§§ A negative GBS screen is considered valid for 5 weeks. If a patient with a history of PTL is re-admitted with signs and symptoms of PTL and had a negative GBS screen >5 weeks prior, she should be rescreened and managed according to this algorithm at that time. From Verani JR, McGee L, Schrag SJ. Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010. MMWR Recomm Rep. Nov 19 2010;59(RR-10):1-36; with permission.

Figure 4

Recommended regimens for intrapartum antibiotic prophylaxis for prevention of early-onset group B streptococcal (GBS) disease. Abbreviation: IV = intravenously. * Broader spectrum agents, including an agent active against GBS, might be necessary for treatment of chorioamnionitis. ^† Doses ranging from 2.5 to 3.0 million units are acceptable for the doses administered every 4 hours following the initial dose. The choice of dose within that range should be guided by which formulations of penicillin G are readily available to reduce the need for pharmacies to specially prepare doses. ^§ Penicillin-allergic patients with a history of anaphylaxis, angioedema, respiratory distress, or urticaria following administration of penicillin or a cephalosporin are considered to be at high risk for anaphylaxis and should not receive penicillin, ampicillin, or cefazolin for GBS intrapartum prophylaxis. For penicillin-allergic patients who do not have a history of those reactions, cefazolin is the preferred agent because pharmacologic data suggest it achieves effective intraamniotic concentrations. Vancomycin and clindamycin should be reserved for penicillin-allergic women at high risk for anaphylaxis. ^¶ If laboratory facilities are adequate, clindamycin and erythromycin susceptibility testingshould be performed on prenatal GBS isolates from penicillin-allergic women at high risk for anaphylaxis. If no susceptibility testing is performed, or the results are not available at the time of labor, vancomycin is the preferred agent for GBS intrapartum prophylaxis for penicillin-allergic women at high risk for anaphylaxis. ** Resistance to erythromycin is often but not always associated with clindamycin resistance. If an isolate is resistant to erythromycin, it might have inducible resistance to clindamycin, even if it appears susceptible to clindamycin. If a GBS isolate is susceptible to clindamycin, resistant to erythromycin, and testing for inducible clindamycin resistance has been performed and is negative (no inducible resistance), then clindamycin can be used for GBS intrapartum prophylaxis instead of vancomycin. From Verani JR, McGee L, Schrag SJ. Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010. MMWR Recomm Rep. Nov 19 2010;59(RR-10):1-36; with permission.

Figure 5

Algorithm for suggested management of chorioamnionitis with a viable fetus. *Broad Spectrum antibiotics consideration may include Ampicillin, Gentamycin, Clindamycin, Flagyl, Erythromycin and Zosyn.

Figure 6

Algorithm for secondary prevention of early-onset group B streptococcal (GBS) disease among newborns. From Verani JR, McGee L, Schrag SJ. Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010. MMWR Recomm Rep. Nov 19 2010;59(RR-10):1-36; with permission. * Full diagnostic evaluation includes a blood culture, a complete blood count (CBC) including white blood cell differential and platelet counts, chest radiograph (if respiratory abnormalities are present), and lumbar puncture (if patient is stable enough to tolerate procedure and sepsis is suspected). ^† Antibiotic therapy should be directed toward the most common causes of neonatal sepsis, including intravenous ampicillin for GBS and coverage for other organisms (including Escherichia coli and other gram-negative pathogens) and should take into account local antibiotic resistance patterns. ^§ Consultation with obstetric providers is important to determine the level of clinical suspicion for chorioamnionitis. Chorioamnionitis is diagnosed clinically and some of the signs are nonspecific. ^¶ Limited evaluation includes blood culture (at birth) and CBC with differential and platelets (at birth and/or at 6--12 hours of life). ** See Table 3 for indications for intrapartum GBS prophylaxis. ^†† If signs of sepsis develop, a full diagnostic evaluation should be conducted and antibiotic therapy initiated. ^§§ If ≥37 weeks' gestation, observation may occur at home after 24 hours if other discharge criteria have been met, access to medical care is readily available, and a person who is able to comply fully with instructions for home observation will be present. If any of these conditions is not met, the infant should be observed in the hospital for at least 48 hours and until discharge criteria are achieved. ^¶¶ Some experts recommend a CBC with differential and platelets at age 6--12 hours.