NEW YORK (Reuters Health) – For most women, a limited course of antibiotic treatment is sufficient for treating chorioamnionitis, according to a report in the June Obstetrics & Gynecology.

“Patients who have chorioamnionitis and who deliver vaginally require only a limited course of treatment (intrapartum plus one dose postpartum) with ampicillin plus gentamicin,” Dr. William Patrick Duff from University of Florida College of Medicine, Gainesville, Florida told Reuters Health in an email. “99% of these individuals will respond to short-term therapy.”

Based on previous work by Dr. Duff and colleagues, an extended course of antibiotics for chorioamnionitis is no longer used at their institution. This retrospective review includes 423 patients treated for chorioamnionitis between 2005 and 2009.

Overall, 399 patients (94%) were treated successfully, and 24 patients (6%) failed treatment.

Seventeen of the women who failed treatment had endometritis, 4 had wound infections, and 3 had septic vein thrombophlebitis.

Twenty-one of the treatment failures were in women who underwent cesarean delivery, and 16 of those had either prolonged rupture of membranes (6 women) or a body mass index (BMI) greater than 30 (10 women). Each of these factors was a significant contributor to treatment failure.

All patients with treatment failure were identified while they were still in the hospital, and none of the women who had an initially uncomplicated hospital course required readmission with a delayed complication of chorioamnionitis.

“For infected patients who require cesarean delivery and who are obese (BMI > 30) and/or who have had prolonged rupture of membranes (> 24 hours), I recommend that they be treated with ampicillin (2 grams Q6h) plus gentamicin (7 mg/kg ideal body weight Q24h) plus either clindamycin (900 mg Q8h) or metronidazole (500 mg Q12 h) until they have been afebrile and asymptomatic for 24 hours,” Dr. Duff said.

“On the basis of this investigation, we now have begun to treat the higher risk patients with a more extended course of therapy,” Dr. Duff said. “After a period of approximately 2 years, we will compare outcomes in these individuals with that observed in our current study. I am reluctant to do this investigation as a randomized controlled trial because I believe that our present data clearly show that short-term treatment is inadequate for the very high risk patients.”

“Chorioamnionitis should be diagnosed quickly and treated aggressively in order to improve outcome for mother and baby,” Dr. Duff added. “Antibiotics need to target specifically group B streptococci and E. coli, which are the dominant pathogens in the neonate. When a mother requires cesarean delivery in the setting of chorioamnionitis, an antibiotic with excellent coverage against anaerobic organisms must also be administered.”

SOURCE:

Limited Course of Antibiotic Treatment for Chorioamnionitis

Obstet Gynecol 2012;119:1102-1105