MULTISTATE CASE-CONTROL STUDY OF MATERNAL RISK-FACTORS FOR NEONATAL GROUP-B STREPTOCOCCAL DISEASE

Risk factors for early onset disease (EOD) caused by Group B streptoco cci (GBS) that are the foundation of prevention guidelines were identi fied in studies conducted in a few hospital centers. We investigated c ases of EOD identified through laboratory-based active surveillance du ring 1991 and 1992 in a multistate population of 17 million. Ninety-ni ne cases were compared with 253 controls matched for hospital, date of birth and birth weight. Prematurity (<37 weeks of gestation) was pres ent in 28% of cases; 53% of case mothers had rupture of membranes >12 hours; and 48% reported intrapartum fever. The incidence of EOD in eac h surveillance area was higher among blacks. By multivariate analysis, case mothers were more likely than controls to have rupture of membra nes before labor onset (adjusted odds ratio 8.7, P < 0.001), intrapart um fever (adjusted odds ratio 11.9, P < 0.001), and history of urinary infection during pregnancy (adjusted odds ratio 4.3, P < 0.05). Young maternal age was also associated with risk of disease. Three-fourths of case mothers had intrapartum fever, <37 weeks of gestation and/or p rolonged rupture of membranes, indicators previously used to select hi gh risk women for intrapartum chemoprophylaxis. Our findings extend da ta from single hospitals and suggest prenatal screening and selective intrapartum chemoprophylaxis of high-risk mothers could potentially pr event the majority of EOD in the United States.