From the Guidelines
The newborn of a GBS-positive, untreated mother delivered vaginally should be managed with observation for ≥48 hours, and a limited evaluation including blood culture and complete blood count with differential is recommended, especially if the infant is <37 weeks or membranes were ruptured ≥18 hours before delivery. According to the guidelines from the CDC in 2010 1, well-appearing infants whose mother had an indication for GBS prophylaxis but received no or inadequate intrapartum antibiotics can be managed with observation for ≥48 hours. The algorithm for secondary prevention of early-onset group B streptococcal disease among newborns, as outlined in the CDC guidelines 1, suggests that if the mother did not receive adequate intrapartum antibiotic prophylaxis, the newborn should undergo a limited evaluation and observation for ≥48 hours if the infant is ≥37 weeks and the duration of membrane rupture is <18 hours. However, if the infant is <37 weeks or the duration of membrane rupture is ≥18 hours, a limited evaluation including blood culture and complete blood count with differential is recommended.
- Key considerations in the management of these newborns include:
- Gestational age: Infants <37 weeks are at higher risk and may require more intensive monitoring and evaluation.
- Duration of membrane rupture: Infants born after prolonged membrane rupture (≥18 hours) are at higher risk and may require more intensive monitoring and evaluation.
- Clinical signs of sepsis: Infants should be closely monitored for signs of sepsis, including temperature instability, respiratory distress, poor feeding, lethargy, or hypotension, and a full diagnostic evaluation should be conducted if any of these signs are present. The CDC guidelines 1 emphasize the importance of observation and limited evaluation for newborns of GBS-positive, untreated mothers, highlighting the need for careful monitoring and prompt intervention if signs of sepsis develop.
From the Research
Management Steps for a Vaginally Delivered Newborn of a GBS Positive, Untreated Mother
- The newborn is at risk of developing early-onset Group B Streptococcal (GBS) infection, which can be life-threatening 2, 3.
- According to studies, asymptomatic neonates born to GBS-colonized mothers should be observed for at least 24 hours for signs of sepsis 3.
- Newborns who appear septic should have a diagnostic work-up, including blood culture, followed by initiation of ampicillin and gentamicin 3.
- Intrapartum antibiotic prophylaxis (IAP) is highly effective in preventing early-onset GBS disease in newborns, with a reduction in incidence of over 80% 4.
- The American Family Physician recommends universal screening for GBS among women at 35 to 37 weeks of gestation, and intrapartum chemoprophylaxis based on maternal allergy history and susceptibility of GBS isolates 3.
Antibiotic Prophylaxis
- Penicillin G is the preferred antibiotic for IAP, with ampicillin as an alternative 2, 3.
- For women allergic to penicillin, erythromycin or clindamycin are options, while vancomycin should be used in cases of resistance or unknown susceptibility 3, 5.
- The risk of anaphylactic reaction to penicillin should be minimized by choosing the prophylactic antibiotic based on maternal allergy history 2.
Vaginal Microbiota
- Intrapartum antibiotic prophylaxis can alter the vaginal microbial community composition, with increased microbial diversity and reduced abundance of Lactobacillus sp. 6.
- GBS positive women receiving intrapartum antibiotic prophylaxis have a modified vaginal microbiota composition, with low abundance of Lactobacillus but higher microbial diversity 6.