Universal screening for group B streptococcus: recommendations and obstetricians' practice decisions

To determine how obstetricians' opinions regarding universal screening of pregnant women for group B streptococcus (GBS) and their responses to positive culture results vary from American Academy of Pediatrics recommendations, and to determine the physician characteristics that predict divergent opinions.

One hundred ninety-four practicing obstetricians in the middle Tennessee region were queried by a mail survey. They were asked if they agreed with universal screening for GBS and to indicate whether they would prescribe antibiotics for women in labor, represented by six scenarios that differed with respect to presence or absence of preterm labor, premature rupture of membranes (ROM), prolonged ROM, and a positive GBS cervical culture. They were also asked to describe their practice and personality characteristics.

Completed surveys were returned by 135 of 194 obstetricians (70%). Although only 28% of the respondents agreed with routine prenatal screening for GBS, most (74%) said they would treat a patient on the basis of a positive culture alone. Other risk factors, when added to a positive culture, slightly increased the decision to treat (from 74 to 88%). Multiple logistic regression, used to assess the relative effect of clinical and physician characteristics on treatment decisions, revealed that chemoprophylaxis for GBS was predicted most strongly by a positive culture at 28 weeks' gestation followed by prolonged ROM and preterm labor. Practicing in an urban location and seeing fewer than 20 patients per day also influenced the decision to treat.

Although most obstetricians in the middle Tennessee region do not believe in universal screening, most will prescribe intrapartum antibiotics on the basis of a positive screening culture. However, other clinical risk factors and physician characteristics significantly and independently affect the decision to treat as well.