Guidelines for Duration of Antibiotics During Labor Refuted

Jessica Illuzzi

The intensive and prolonged observation of infants at risk for group B streptococcus (GBS) may not benefit the infant and may heighten parental anxiety, researchers at Yale School of Medicine report in a recent article in Obstetrics & Gynecology.

Current Centers for Disease Control and Prevention (CDC) guidelines recommend at least four hours of antibiotics to treat GBS in pregnant women in labor. About 50 percent of women with GBS are unable to receive the full four hours of treatment due to rapid labor and delivery. The CDC considers their newborns “at risk” for GBS and recommends blood tests and 48 hours of observation in the hospital.

Researchers from Yale School of Medicine’s Departments of Obstetrics, Gynecology & Reproductive Sciences (Ob/Gyn), and Epidemiology and Public Health (EPH) sought evidence to support the CDC guidelines. They conducted a systematic review of all published studies that included the duration of GBS antibiotic treatment of women in the delivery room and the numbers of infants who developed GBS. They calculated risk ratios for GBS colonization or sepsis based on duration of treatment.

“Neither the pharmacologic literature nor the clinical literature provide evidence to support the current CDC guidelines about duration of antibiotic prophylaxis during labor,” said Jessica Illuzzi, M.D., assistant professor in Yale Ob/Gyn who conducted the study with Michael Bracken, the Susan Dwight Bliss Professor of Epidemiology in EPH and Professor of Neurology and Ob/Gyn.

“The current protocol results in large numbers of low risk newborns undergoing invasive, expensive neonatal testing and prolonged observation, despite the lack of evidence that this group of infants is at higher risk for GBS infection,” Illuzzi added.

She said the pharmacologic literature reveals that effective levels of antibiotics are detectable in the fetal bloodstream and amniotic fluid as early as five minutes after treatment begins. The risk of neonatal GBS infection is also significantly reduced after one to two hours of treatment.

“Ultimately, we hope the CDC guidelines will be re-evaluated and revised to reflect the evidence so that resources, invasive testing and prolonged observation are directed to infants truly at risk for GBS disease,” said Illuzzi.

Future research by Illuzzi and Bracken include a possible prospective study to measure the duration of treatment and the spread of GBS among newborns.

Citation: Obstetrics & Gynecology, Vol. 108, No. 5 (November 2006)

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