From the Guidelines
The most appropriate response to this patient is to reassure her that all pregnant women are screened for Group B Streptococcus (GBS) between 36-37 weeks of gestation, and if positive, she will receive intravenous antibiotics during labor to prevent transmission to her baby. Since she is currently at 30 weeks, this screening will be performed in about 6-7 weeks. The standard regimen for GBS prophylaxis during labor is intravenous penicillin G (5 million units initially, then 2.5 million units every 4 hours until delivery) or ampicillin (2 grams initially, then 1 gram every 4 hours until delivery) 1. For penicillin-allergic patients, alternatives include cefazolin, clindamycin, or vancomycin depending on susceptibility testing. GBS is a common bacterium that colonizes the vaginal and rectal areas in about 25% of pregnant women. While maternal colonization is typically asymptomatic, it can cause serious infections in newborns including pneumonia, sepsis, and meningitis if transmitted during delivery. Universal screening and intrapartum antibiotic prophylaxis have significantly reduced the incidence of early-onset GBS disease in newborns, with an estimated 80% decrease in early-onset GBS infection 1. The patient should be reassured that following this standard protocol is highly effective at preventing neonatal GBS infection. Some key points to consider include:
- Women whose culture results are unknown at the time of delivery should be managed according to the risk-based approach, with obstetric risk factors including delivery at <37 weeks' gestation, duration of membrane rupture >18 hours, or temperature >100.4ºF [>38.0ºC] 1.
- Women with negative vaginal and rectal GBS screening cultures within 5 weeks of delivery do not require intrapartum antimicrobial prophylaxis for GBS even if obstetric risk factors develop 1.
- Women with GBS bacteriuria in any concentration during their current pregnancy or who previously gave birth to an infant with GBS disease should receive intrapartum antimicrobial prophylaxis 1. It is essential to follow the most recent guidelines for the prevention of perinatal group B streptococcal disease, which recommend universal screening and intrapartum antibiotic prophylaxis for women with positive screening results 1.
From the Research
Patient Concerns and Risk Factors
- The patient is concerned about the risk of neonatal group B streptococcal infection due to her niece's recent death from the condition.
- The patient is at 30 weeks gestation and has had an uncomplicated prenatal course with normal laboratory results, including a negative urine culture during the first trimester.
- The patient has no chronic medical conditions or medication allergies.
Group B Streptococcal Infection Prevention
- According to the American College of Obstetricians and Gynecologists, universal prenatal screening by vaginal-rectal culture is recommended between 36 0/7 and 37 6/7 weeks of gestation to prevent group B streptococcal early-onset disease (EOD) 2.
- Intrapartum antibiotic prophylaxis is effective in preventing GBS EOD, and penicillin, ampicillin, or cefazolin are recommended for prophylaxis 3.
- The risk of early neonatal GBS infection increases in cases of preterm delivery, maternal fever during delivery, and membrane rupture more than 18 hours before delivery 4.
Appropriate Response to the Patient
- The patient should be informed about the risks and benefits of intrapartum antibiotic prophylaxis and the importance of universal prenatal screening for GBS colonization.
- The patient's concerns and questions should be addressed, and she should be reassured that her healthcare provider will monitor her and her baby's health closely.
- The patient should be advised to follow the recommended guidelines for GBS screening and intrapartum antibiotic prophylaxis to minimize the risk of GBS EOD 5, 6.
- The patient should be encouraged to ask questions and seek clarification on any concerns she may have regarding GBS infection and its prevention.