Table 4.

Construction of Strategies for Prevention of EOGBS Based on Gestational Age and Intrapartum Risk Factors

StrategyLast Subgroup Designated for ProphylaxisCumulative Effects of Strategy
Gestational
Age
(Weeks)
Intrapartum
Risk
Factors
Intervention% in Which
EOGBS Is
Prevented
Mothers Treated
per 1000 Births
Infants Treated
per 1000 Births
EOGBS Cases
Prevented
(% of Expected)
1<28+Intrapartum20.3370.600.004.1
228–30+Intrapartum10.3851.280.006.5
331–33+Intrapartum5.0532.870.009.1
4<28+Postpartum3.7272.870.609.9
534–36+Intrapartum2.4367.780.6013.9
6<28Intrapartum2.22615.180.6019.4
728–30+Postpartum1.90315.181.2819.8
8≥37+Intrapartum1.12282.951.2845.1
928–30Intrapartum0.99091.271.2847.9
1031–33+Postpartum0.92691.272.8748.4
1131–33Intrapartum0.451110.682.8751.3
1234–36+Postpartum0.447110.687.7852.0
13<28Postpartum0.408110.6815.1853.0
1434–36Intrapartum0.221170.7715.1857.2
15≥37+Postpartum0.206170.7782.9561.9
1628–30Postpartum0.182170.7791.2762.4
17≥37Intrapartum0.0961000.0091.2788.8
1831–33Postpartum0.0821000.00110.6889.3
1934–36Postpartum0.0391000.00170.7790.1
20≥37Postpartum0.0181000.001000.0094.9
  • Abbreviation: EOGBS, early-onset neonatal group B streptococcus infection.