Methods: All pregnant women with a positive culture for GBS in a five year period, 1-1-2009 to 12-31-2014, were identified using Southern California Kaiser Permanente electronic health records. Those with a history of an active, but unverified, penicillin allergy noted prior to delivery were compared to those with no penicillin allergy history. Method of delivery, hospital utilization over the 6 months after delivery, and antibiotic exposures within 3 days of delivery was determined.
Results: There were 39,374 (23.1%) GBS-positive women with 42,524 pregnancies, 3,500 (8.2%) with unverified penicillin allergy and 39,024 (91.8%) with no history of penicillin allergy. There were significantly more caesarean sections in women with unverified penicillin allergy, 30.4% versus 27.6% (p=0.0004). Mothers with unverified penicillin allergy spent significantly more days in the hospital in the 6 months after delivery, 3.55±1.51 versus 3.46±2.00 (p = 0.002). GBS-positive pregnant women with unverified penicillin allergy were significantly more likely to receive clindamycin or vancomycin. Only 7 GBS-positive women had penicillin allergy testing at Kaiser Permanente Southern California during this time.
Conclusions: Penicillin allergy testing pregnant women who are GBS-positive prior to delivery may result in decreased hospital utilization, as well as less morbidity.