American Journal of Obstetrics and Gynecology
Ampicillin for neonatal group B streptococcal prophylaxis: How rapidly can bactericidal concentrations be achieved?☆,☆☆,★
Section snippets
MATERIAL AND METHODS
Ampicillin was administered at arbitrarily determined time intervals before delivery in term parturients who were not in labor and who were undergoing elective cesarean delivery. The study protocol was approved by the Institutional Review Board of the University of Texas Southwestern Medical Center at Dallas, and informed written consent was obtained from each participant. Women who had ruptured membranes, signs of infection, or an allergy to penicillin were excluded. A standard 2 gm dose of
RESULTS
Between June 16, 1995, and September 19, 1995, 40 women consented to participate in this investigation. The women ranged in age from 18 to 40 years (27 ± 6 years [mean ± SD]). The gestational age at delivery was 39 ± 1 week (mean ± SD). The majority of patients received regional anesthetics (n = 34) and the remainder received general anesthetics (n = 6). The umbilical artery pH was 7.26 ± 0.06 (mean ± SD), and all infants were born in good condition. No infant had neonatal sepsis.
The time
COMMENT
After an intravenous infusion of 2 gm of ampicillin, concentrations well in excess of the minimum bactericidal concentration reported for group B streptococci3, 4 were achieved within 3 minutes in all maternal and umbilical cord blood samples. In contrast, bactericidal concentrations were not achieved in the amniotic fluid in 15% of the pregnancies studied. We speculate that the variability observed in amniotic fluid ampicillin levels may reflect whether ampicillin excretion by fetal
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Cited by (53)
A Proposed Framework for the Clinical Management of Neonatal “Culture-Negative” Sepsis
2022, Journal of PediatricsThe transplacental passage of commonly used intrapartum antibiotics and its impact on the newborn management: A narrative review
2019, Early Human DevelopmentCitation Excerpt :It is a small molecule (349 Da), minimally protein-bound (18%) and characterized by good tissue penetration [27]. There is good evidence to suggest that it crosses the term placenta very rapidly (as early as within 5 min, and peaks at 30 min) and reaches bactericidal levels in fetal serum (2.5–70 times higher than MIC) for up to 4–5 h after birth [7,28,29] (Table 2). The impact of IAI on the rate of transfer is unknown [30].
Intrapartum antibiotic prophylaxis for Group B Streptococcus: Has the time come to wait more than 4 hours?
2014, American Journal of Obstetrics and GynecologyCitation Excerpt :However, despite adequate bactericidal levels in fetal cord blood, 15% of their mothers will have amniotic fluid antibiotic concentrations below the minimal inhibitory concentration for GBS.7 Cases of neonatal GBS sepsis that occur with short durations of maternal antibiotic prophylaxis (ie, <4 hours) may either be the result of the following: (1) fetal exposure to GBS in utero prior to antibiotic administration when tissue injury by GBS may not be quickly reversible or (2) inadequate time for antibiotics to decrease vaginal GBS colony counts.6,7 Most published medical literature on intrapartum antibiotic prophylaxis for GBS suggest a 4 hour time threshold for antibiotic exposure.
Neonatal group B streptococcal disease: From pathogenesis to preventive strategies
2011, Clinical Microbiology and InfectionPharmacokinetics and Target Attainment of Antimicrobial Drugs Throughout Pregnancy: Part I—Penicillins
2023, Clinical Pharmacokinetics
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From the Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center.
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Reprint requests: Steven L. Bloom, MD, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75235-9032.
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