Benzylpenicillin concentrations in umbilical cord blood and plasma of premature neonates following intrapartum doses for group B streptococcal prophylaxis

BACKGROUND AND METHOD

Dutch obstetrics guideline suggest an initial maternal benzylpenicillin dose of 2,000,000 IU followed by 1,000,000 IU every 4 h for group-B-streptococci (GBS) prophylaxis. The objective of this study was to evaluate whether concentrations of benzylpenicillin reached concentrations above the minimal inhibitory concentrations (MIC) in umbilical cord blood (UCB) and neonatal plasma following the Dutch guideline.

RESULTS

Forty-six neonates were included. A total of 46 UCB samples and 18 neonatal plasma samples were available for analysis. Nineteen neonates had mothers that received intrapartum benzylpenicillin. Benzylpenicillin in UCB corresponded to concentrations in plasma drawn directly postpartum (R2 = 0.88, p < 0.01). A log-linear regression suggested that benzylpenicillin concentrations in neonates remained above the MIC threshold 0.125 mg/L up to 13.0 h after the last intrapartum dose.

CONCLUSIONS

Dutch intrapartum benzylpenicillin doses result in neonatal concentrations above the MIC of GBS.

Antibiotic choice for Group B Streptococcus prophylaxis in mothers with reported penicillin allergy and associated newborn outcomes

OBJECTIVE

To evaluate the choice of antibiotic used for intrapartum Group B Streptococcus (GBS) prophylaxis in pregnant individuals with reported penicillin allergies compared to those without reported penicillin allergies and investigate whether there are associated differences in neonatal outcomes.

STUDY DESIGN

This retrospective cohort study included mother-infant dyads of GBS positive pregnant individuals who labored and delivered newborns ≥ 35 weeks of gestation at a high-volume urban hospital (2005-2018). The type of antibiotic administered to the mothers for GBS prophylaxis (beta-lactam prophylaxis defined as penicillin-class drug or cefazolin; alternative prophylaxis defined as vancomycin or clindamycin) was compared between those with a penicillin allergy documented in their medical record versus those who did not. Neonatal outcomes included number of postnatal blood draws, antibiotic administration, neonatal intensive care unit (NICU) admission, bacteremia, and hospital length of stay and were compared between groups. Bivariable and multivariable analyses were performed.

RESULTS

Of 11,334 mother-infant pairs, 1170 (10.3%) mothers had a penicillin allergy documented in their medical record. Of them, 49 (4.2%) received a penicillin, 259 (22.1%) received cefazolin, 449 (38.4%) received clindamycin, and 413 (35.3%) received vancomycin. Patients with a reported penicillin allergy were significantly more likely to receive alternative GBS prophylaxis compared to those without penicillin allergy (73.7% vs. 0.2%, p < 0.01). Neonates of patients who received alternative GBS prophylaxis were significantly more likely to undergo a postnatal lab draw compared to neonates of patients who received beta-lactam antibiotics (20.8% vs. 17.3%, OR 1.25 (95% CI 1.08-1.46)). This significant association persisted after adjusting for potential confounders (aOR 1.23, 95% CI 1.06-1.43). There were no other significant differences seen in other newborn outcomes.

CONCLUSION

Pregnant individuals who report a penicillin allergy were more likely to receive alternative antibiotics for GBS prophylaxis compared to those without a penicillin allergy. This was associated with an increased frequency of postnatal blood draws among neonates of mothers with a reported penicillin allergy. Administration of alternative intrapartum antibiotic prophylaxis with vancomycin or clindamycin is common in individuals with self-reported penicillin allergy, and maternal alternative antibiotic administration may impact neonatal care, particularly via increased lab draws.

Vancomycin during delivery hospitalizations for women with group B streptococcus

OBJECTIVE

Vancomycin use for intrapartum GBS prophylaxis is not well characterized. The objective of this study was to describe trends in the use of vancomycin among women undergoing vaginal delivery with group B Streptococcus (GBS) colonization.

METHODS

An administrative inpatient database that includes medications was analyzed to evaluate antibiotic use in women undergoing vaginal delivery hospitalizations complicated by GBS colonization from January 2006 to March 2015. Patients with other obstetric or infectious indications for antibiotics were excluded. Frequency of use of individual antibiotic agents was determined. The Cochran-Armitage test was used to assess temporal trends. An adjusted log-linear regression model accounting for demographic and hospital factors with vancomycin receipt as the outcome was performed with adjusted risk ratios (aRR) and 95% confidence intervals (CI) as the measure of effect. Hospital level variation in administration of vancomycin was also evaluated.

RESULTS

469,717 deliveries met inclusion criteria and were included in this analysis. Use of vancomycin increased from 0.8% of patients in 2006 to 3.8% of patients in the first quarter of 2015. Comparing 2015 to 2006 both the unadjusted (relative risk 4.89 95% CI 4.26-5.60) and adjusted (aRR 4.52 95% 3.94-5.19) models demonstrated significantly increased likelihood of vancomycin administration. In evaluating hospital level vancomycin use, variation was noted with 8.0% of centers administering vancomycin to ≥6.0% of patients.

CONCLUSIONS

Vancomycin is becoming increasingly commonly used for intrapartum GBS prophylaxis. Further research and quality improvements initiatives are indicated to optimize intrapartum GBS antibiotic prophylaxis.

Intrapartum Group B Streptococcus Antibiotic Prophylaxis in Penicillin Allergic Pregnant Women

Objectives  To estimate the prevalence of and identify modifiable risk factors for alternative antibiotics for group B Streptococcus (GBS) prophylaxis in penicillin-allergic women. Methods  Retrospective cohort study of pregnant women within a health care network from January 1, 2014, to December 31, 2017. Included women were GBS colonized, delivered at ≥ 37 weeks' gestation, and reported penicillin/cephalosporin allergy. The primary outcome was the use of alternate antibiotics GBS prophylaxis, defined per Centers for Disease Control and Prevention guidelines as antibiotics other than penicillin, ampicillin, or cefazolin. Results  We identified 190 GBS-colonized pregnant women self-reporting a penicillin/cephalosporin allergy; 5% reported anaphylaxis, 44% high-risk symptoms (isolated hives, shortness of breath, swelling, or vomiting), and 51% low-risk symptoms (isolated rash, itching, or nausea). Two-thirds (63%) had alternative antibiotic prophylaxis. In adjusted analyses, nonwhite race (adjusted odds ratio [aOR]: 2.42; 95% confidence interval [CI]: 1.19-4.94) and high-risk allergic reaction (aOR: 2.42; 95% CI: 1.30-4.49) were associated with higher odds of alternative antibiotics prophylaxis compared with low-risk allergic reaction. Low-risk allergic reaction group was less likely to receive alternative antibiotic prophylaxis (aOR: 0.36; 95 CI%: 0.19-0.66). Conclusion  Alternative antibiotic use for GBS prophylaxis is frequent with penicillin/cephalosporin allergies. Efforts to confirm allergy and perform penicillin hypersensitivity testing may increase compliance with guidelines for antibiotic administration.