Background. Infants born to mothers who are colonized with group B streptococcus (GBS) but received <4 hours of intrapartum antibiotic prophylaxis (IAP) are at-risk for presenting later with sepsis. We assessed if <4 hours of maternal IAP for GBS are associated with an increased incidence of clinical neonatal sepsis. Materials and Methods. A retrospective cohort study of women-infant dyads undergoing IAP for GBS at ≥37-week gestation who presented in labor from January 1, 2003 through December 31, 2007 was performed. Infants diagnosed with clinical sepsis by the duration of maternal IAP received (< or ≥4-hours duration) were determined. Results. More infants whose mothers received <4 hours of IAP were diagnosed with clinical sepsis, 13 of 1,149 (1.1%) versus 15 of 3,633 (0.4%), . Multivariate logistic regression analysis showed that treatment with ≥4 hours of IAP reduced the risk of infants being diagnosed with clinical sepsis by 65%, adjusted relative risk 0.35, CI 0.16–0.79, and . Conclusion. The rate of neonatal clinical sepsis is increased in newborns of GBS colonized mothers who receive <4 hours compared to ≥4 hours of IAP. 1. Introduction Guidelines for group B streptococcus (GBS) originally established in 1996 (and reaffirmed in 2002 and 2010) by the Centers for Disease Control and Prevention (CDC) identify asymptomatic infants born to mothers who were colonized with GBS but received <4 hours of intrapartum antibiotics, as at-risk for presenting later with sepsis [1–3]. Past management recommendations for infants have been limited either to evaluation with a blood culture and complete blood count or more recently only just to observation for ≥48 hours [1–3]. The origin of this four-hour duration for intrapartum GBS antibiotic prophylaxis is unclear. In the presence of at least one risk factor such as premature delivery <37-week gestation, rupture of membranes >6 hours, or maternal fever of ≥37.5°C, intrapartum antibiotic prophylaxis of <4 hours results in higher rates of vertical transmission of neonatal GBS colonization [4, 5]. Yet even in the presence of maternal risk factors, if intrapartum antibiotic was given at least 2 hours before delivery, the effectiveness in preventing early onset group B streptococci disease was demonstrated [6]. However, the majority of infants exposed to GBS at birth are delivered to colonized mothers without additional risk factors. Small prospective observation studies in women without risk factors have shown a lower rate of infant colonization with GBS, if maternal intrapartum prophylaxis was >4-hour duration
References
[1]
Centers for Disease Control Prevention, “Prevention of perinatal group B streptococcal disease: a public health perspective,” Morbidity and Mortality Weekly Report, vol. 45, no. RR-7, pp. 1–24, 1996.
[2]
Centers for Disease Control Prevention, “Prevention of perinatal group B streptococcal disease. Revised guidelines from CDC,” Morbidity and Mortality Weekly Report, vol. 51, no. RR-11, pp. 1–22, 2002.
[3]
Centers for Disease Control Prevention, “Prevention of perinatal group B streptococcal disease. Revised guidelines from CDC,” Morbidity and Mortality Weekly Report, vol. 59, no. RR-10, pp. 1–22, 2010.
[4]
K. M. Boyer, C. A. Gadzala, P. D. Kelly, and S. P. Gotoff, “Selective intrapartum chemoprophylaxis of neonatal group B streptococcal early-onset disease. III. Interruption of mother-to-infant transmission,” Journal of Infectious Diseases, vol. 148, no. 5, pp. 810–816, 1983.
[5]
M. Pylipow, M. Gaddis, and J. S. Kinney, “Selective intrapartum prophylaxis for group B Streptococcus colonization: management and outcome of newborns,” Pediatrics, vol. 93, no. 4, pp. 631–635, 1994.
[6]
F. Y. C. Lin, R. A. Brenner, Y. R. Johnson et al., “The effectiveness of risk-based intrapartum chemoprophylaxis for the prevention of early-onset neonatal group B streptococcal disease,” The American Journal of Obstetrics and Gynecology, vol. 184, no. 6, pp. 1204–1210, 2001.
[7]
M. de Cueto, M. J. Sanchez, A. Sampedro, J. A. Miranda, A. J. Herruzo, and M. Rosa-Fraile, “Timing of intrapartum ampicillin and prevention of vertical transmission of group B Streptococcus,” Obstetrics and Gynecology, vol. 91, no. 1, pp. 112–114, 1998.
[8]
D. Lijoi, E. D. Capua, S. Ferrero et al., “The efficacy of 2002 CDC guidelines in preventing perinatal group B Streptococcal vertical transmission: a prospective study,” Archives of Gynecology and Obstetrics, vol. 275, no. 5, pp. 373–379, 2007.
[9]
A. Berardi, C. Rossi, A. Biasini et al., “Efficacy of intrapartum chemoprophylaxis less than 4 hours duration,” Journal of Maternal-Fetal and Neonatal Medicine, vol. 24, no. 4, pp. 619–625, 2011.
[10]
J. L. Illuzzi and M. B. Bracken, “Duration of intrapartum prophylaxis for neonatal group B streptococcal disease: a systematic review,” Obstetrics and Gynecology, vol. 108, no. 5, pp. 1254–1265, 2006.
[11]
International Classification of Diseases 9th revision, Clinical Modification, St. Anthony Publishing (Ingenix), Salt Lake City, Utah, USA, 6th edition, 2008.
[12]
M. C. Ottolini, K. Lundgren, L. J. Mirkinson, S. Cason, and M. G. Ottolini, “Utility of complete blood count and blood culture screening to diagnose neonatal sepsis in the asymptomatic at risk newborn,” Pediatric Infectious Disease Journal, vol. 22, no. 5, pp. 430–434, 2003.
[13]
P. Bromberger, J. M. Lawrence, D. Braun, B. Saunders, R. Contreras, and D. B. Petitti, “The influence of intrapartum antibiotics on the clinical spectrum of early-onset group B streptococcal infection in term infants,” Pediatrics, vol. 106, no. 2 I, pp. 244–250, 2000.
[14]
G. J. Escobar, D. K. Li, M. A. Armstrong et al., “Neonatal sepsis workups in infants ≥2000 grams at birth: a population-based study,” Pediatrics, vol. 106, no. 2 I, pp. 256–263, 2000.
[15]
W. P. Goins, T. R. Talbot, W. Schaffner et al., “Adherence to perinatal group B streptococcal prevention guidelines,” Obstetrics and Gynecology, vol. 115, no. 6, pp. 1217–1224, 2010.
[16]
S. J. Schrag, E. R. Zell, R. Lynfield et al., “A population-based comparison of strategies to prevent early-onset group B streptococcal disease in neonates,” The New England Journal of Medicine, vol. 347, no. 4, pp. 233–239, 2002.
[17]
M. de Cueto, M. J. Sanchez, L. Molto et al., “Efficacy of a universal screening program for the prevention of neonatal group B streptococcal disease,” The European Journal of Clinical Microbiology and Infectious Diseases, vol. 14, no. 9, pp. 810–812, 1995.
[18]
S. L. Bloom, S. M. Cox, R. E. Bawdon, and L. C. Gilstrap, “Ampicillin for neonatal group B streptococcal prophylaxis: how rapidly can bactericidal concentrations be achieved?” The American Journal of Obstetrics and Gynecology, vol. 175, no. 4 I, pp. 974–976, 1996.
[19]
D. F. Colombo, J. L. Lew, C. A. Pedersen, J. R. Johnson, and P. Fan-Havard, “Optimal timing of ampicillin administration to pregnant women for establishing bactericidal levels in the prophylaxis of group B Streptococcus,” The American Journal of Obstetrics and Gynecology, vol. 194, no. 2, pp. 466–470, 2006.
[20]
E. L. Barber, G. Zhao, I. A. Buhimschi, and J. L. Illuzzi, “Duration of intrapartum prophylaxis and concentration of penicillin G in fetal serum at delivery,” Obstetrics and Gynecology, vol. 112, no. 2, pp. 265–270, 2008.
[21]
D. A. Grimes, “False alarms and pseudo-epidemics. The limitations of observational epidemiology,” Obstetrics and Gynecology, vol. 120, no. 4, pp. 920–927, 2012.
