Adherence to perinatal group B streptococcal prevention guidelines

Abstract

Objective: To estimate compliance with the 2002 revised perinatal group B streptococci (GBS) prevention guidelines in Tennessee, which recommend universal GBS screening of pregnant women at 35-37 weeks of gestation and, when indicated, administration of intrapartum chemoprophylaxis.

Methods: Active Bacterial Core surveillance conducts active, population-based surveillance for invasive GBS disease in 11 Tennessee counties. A retrospective case-cohort study was conducted using a stratified random sample of all live births in surveillance hospitals during 2003-2004, including all early-onset GBS cases. Factors associated with GBS screening and lack of optimal GBS chemoprophylaxis were analyzed using logistic regression.

Results: Screening was performed for 84.7% of pregnant women, but 26.3% of prenatal tests with documented test dates were performed before 35 weeks of gestation. Among women with an indication for GBS prophylaxis, 61.2% received optimal chemoprophylaxis, defined as initiation of a recommended antibiotic 4 hours or more before delivery. When the analysis was restricted to women who were admitted 4 hours or more before delivery, 70.9% received optimal chemoprophylaxis. Women not receiving optimal chemoprophylaxis were more likely to have penicillin allergy (11.7% compared with 2.5%, adjusted odds ratio [OR] 8.58, 95% confidence interval [CI] 1.57-47.04) or preterm delivery (45.5% compared with 13.2%, adjusted OR 5.52, 95% CI 2.29-13.30) and were less likely to have received the recommended prenatal serologic testing for other infectious diseases (77.9% compared with 91.1%, adjusted OR 0.30, 95% CI 0.09-0.98). Forty cases of early-onset GBS were identified (0.36 per 1,000 live births); 25% of these neonates were born to women who received screening at 35 weeks of gestation or later and, when indicated, optimal chemoprophylaxis.

Conclusion: Universal prenatal GBS screening was implemented widely in Tennessee, although the timing of screening and administration of chemoprophylaxis often were not optimal. A substantial burden of early-onset GBS disease occurs despite optimal prenatal screening and chemoprophylaxis, suggesting that alternative strategies, such as vaccination, are needed.

Level of evidence: II.