Whenever antibiotics are taken, there is always a risk of antibiotic resistance developing. When antibiotics are given to pregnant women, this could affect the mother and her baby.
Data are collected by Public Health England on the susceptibility of group B Streptococci to particular antibiotics.
GBS is still universally sensitive to Penicillin (the drug of choice for intrapartum antibiotic prophylaxis against early-onset group B Strep infection), but there has been a significant increase in GBS resistance to clindamycin. Clindamycin was the drug usually offered to women who had an allergy to penicillin to minimise the risk of an allergic reaction. However, it is no longer recommended as the resistance rate is high. In 2010, 452 GBS isolates were tested and 8% were resistant to Clindamycin. In 2015, 911 GBS isolates were tested and 23% were resistant to Clindamycin.
For women allergic to penicillin, provided the woman has not had severe allergy to penicillin, a cephalosporin should be used. If there is any evidence of severe allergy to penicillin, vancomycin should be used.
This situation continues to be monitored by the PHE. Reports on resistance are included in the data series available here.