Re: Question about GBS treatment in labor vs prenatally
From: Efrain Ramirez (eramirezt@coqui.net)
Sat Aug 25 09:00:44 2007
I treat GBS once if positive in urine culture - then prophylaxis.. the
future is GBS vaccine.
Ef
> At Sat, 25 Aug 2007, GIN11153@aol.com wrote:
>
>As a longtime L&D nurse, I remember when moms were treated for GBS during
>pregnancy, thus attempting to avoid some of the potential complication of GBS
>such as PPROM, preterm labor, chorioamnionitis, etc. I don't understand the
>concept of why nowadays women aren't treated until they go into labor, usually
>weeks after the culture comes back positive which potentially could mean that
>the fetus is affected by the infection for at least 4-5 weeks. Someone posted
> these articles on another listserv that brought this topic up in my mind
>again-thoughts appreciated for my learning experience:
>
>Obstet Gynecol. 1997 Aug;90(2):240-Obs
>
>Persistence of penicillin G benzathine in pregnant group B streptococcus
>carriers.
>Weeks JW, Myers SR, Lasher L, Goldsmith J, Watkins C, Gall SA.
>
>Department of Obstetrics & Gynecology, Louisiana State University School of
>Medicine, Shreveport, USA. _jweeks1@mail.jweeks1@mjwe_
>(mailto:jweeks1@mail.sh.lsumc.edu)
>
>OBJECTIVE: To determine if streptococcicidal levels of penicillin G
>benzathine can be detected in maternal serum 4 weeks after treatment with 4.8 million
>units. METHODS: Thirty-seven pregnant women with positive group B
>streptococcus vaginal or urine cultures were each given 4.8 million units of penicillin
>G benzathine. Maternal blood samples were collected after injection and at
>delivery. Serum penicillin levels were measured by high-pressure liquid
>chromatography. Follow-up cultures were done when possible. RESULTS: None of the
>patients had serum penicillin levels below 0.20 microgram/mL 30 days after
>treatment. Cord blood levels were approximately 50% lower than maternal levels.
>In all but three subjects, cord blood levels exceeded 0.06 microgram/mL, the
>minimal inhibitory concentration for group B streptococcus. The three
>exceptions were patients who delivered more than 100 days after treatment. Group B
>streptococcus cultures were negative at the time of delivery in 72% of cases.
>None of the patients with positive cultures were moderately or heavily
>colonized. CONCLUSION: In pregnant women, penicillin G benzathine levels are high
>enough to inhibit the growth of group B streptococcus for more than 4 weeks
>after injection with 4.8 million units. Further studies are needed to evaluate
>whether this regimen can prevent neonatal colonization and invasive group B
>streptococcus disease.
>
>PMID: 9241301
>
>Am J Obstet Gynecol. 2000 Aug;183(2):372-Am
>
>Late third-trimester treatment of rectovaginal group B streptococci with
>benzathine penicillin G.
>Bland ML, Vermillion ST, Soper DE.
>
>Department of Obstetrics and Gynecology, Medical University of South
>Carolina, Charleston 29425, USA.
>
>OBJECTIVE: We sought to determine the efficacy of late third-trimester
>benzathine penicillin G administration in eradicating maternal group B
>streptococcal colonization at delivery. STUDY DESIGN: We performed a prospective trial
>of late third-trimester treatment with benzathine penicillin G versus
>observation in 78 obstetric patients colonized with group B streptococci. Patients
>were screened by use of rectovaginal swabs cultured in selective media between
>34 and 37 completed weeks' gestation. Patients with positive cultures were
>offered antepartum treatment with 4.8 million units of intramuscular benzathine
>penicillin G or observation. Participants in both groups were recultured at
>their delivery admission before receiving standard intrapartum therapy. The
>primary outcome was the frequency of persistent maternal group B streptococcal
>colonization at the delivery admission. Other outcome variables included
>semiquantitative growth characteristics of all group B streptococcal cultures,
>the frequency of neonatal sepsis, and adverse maternal effects. Data were
>analyzed by the Student t test for continuous variables and the chi(2) or Fisher
>exact test for categoric variables, with significance established at P <.05.
>RESULTS: Both groups were similar with respect to selected demographics,
>gestational age at delivery, and frequency of heavy group B streptococcal growth
>in initial screening cultures. The mean interval from treatment until
>delivery was 19.4 +/- 7.5 days (mean +/- SD). There were no cases of neonatal sepsis
>in either group or any adverse maternal effects attributed to the treatment.
>Group B streptococcal culture characteristics at delivery admission were as
>follows. Positive results for group B streptococci were found in 7 (25%)
>treated patients and 41 (82%) patients under observation (relative risk, 0.30;
>95% confidence interval, 0.16-0.59; P <.0001). Positive results for heavy
>growth of group B streptococci were found in 0 (0%) treated patients and 31 (62%)
>patients under observation (relative risk, 0.01; 95% confidence interval,
>0.00-0.12; P <.0001). CONCLUSIONS: Treating group B streptococci carriers with
>benzathine penicillin G in the late third trimester eradicates or
>significantly reduces maternal group B streptococcal colonization at delivery. This may
>provide an adjuvant therapy to those mothers at risk for receiving inadequate
>intrapartum antibiotic prophylaxis against group B streptococci.
>
>PMID: 10942472
>
>J Matern Fetal Neonatal Med. 2005 May;17(5):333-J M
>
>Efficacy of intramuscular penicillin in the eradication of group B
>streptococcal colonization at delivery.
>Pinette MG, Thayer K, Wax JR, Blackstone J, Cartin A.
>
>Division of Maternal-Fetal Medicine, Department of Obstetrics and
>Gynecology, Maine Medical Center, Portland, Maine 04102, USA.
>
>OBJECTIVE: Due to rapid deliveries and human error, not all group B
>streptococcal positive mothers will receive adequate prophylactic antibiotic
>treatment in labor. We sought to determine if long acting intramuscular penicillin
>given after a positive culture result would be efficacious in eradicating group
>B streptococcal colonization at the time of delivery. METHODS: Patients
>positive for group B streptococci at 35-37 weeks were randomized to receive 2.4
>million units of intramuscular benzathine penicillin G suspension (Bicillin
>L-A) versus no treatment. Study patients were recultured at the time of
>admission to labor and delivery prior to receiving prophylactic antibiotics
>according to CDC guidelines. RESULTS: A total of 53 patients were enrolled. A small
>but significant decrease in the rate of group B streptococcal colonization was
>observed in the treatment group (14/27, 52%) versus the control group
>(20/23, 87%), p=0.03. CONCLUSION: The large number of persistent carriers suggests
>that 2.4 million units of intramuscular benzathine penicillin G suspension
>(Bicillin L-A) is insufficient as sole therapy. However, the decline in group B
>streptococcal carriers might lessen the risk of failed or insufficient
>intrapartum treatment. Intramuscular benzathine penicillin G suspension (Bicillin
>L-A) may be useful as an adjunctive treatment for patients at risk for rapid
>delivery, before adequate intrapartum prophylaxis can be given.
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>
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>Gail Neuman RNC CPHW
>---------------------------------------------------------------------------
>student midwife and student nurse practitioner
>---------------------------------------------------------------------------
>certified high risk OB
>---------------------------------------------------------------------------
>Perinatal Nurse Associates
>801 N. Tustin Ave., Suite 305
>Santa Ana, CA 92705
>(714) 314-7070
>(714) 838-1479 fax
>
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“ The greatest obstacle to knowledge is not ignorance,
it is the illusion of knowledge.” Daniel J. Boorstin - Historian
