Association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis among patients undergoing induction of labor at term

Defining Appropriate Comparator Populations for Placental Pathology for Pregnant People With HIV

Background. Widespread adoption of antiretroviral therapy has reduced perinatal transmission of HIV; however, people living with HIV (PWH) have higher rates of preterm birth and hypertensive disorders of pregnancy. The placenta is the critical fetal support organ in pregnancy, and multiple investigations have sought associations in PWH between HIV and placental pathology. However, results have been inconclusive. We posit that selection of control group populations influences the apparent anomalies in placentas from PWH and examined the differences seen between these placentas and those of four comparator populations. Methods. Placentas from PWH were compared with those from all patients without HIV, controls from a recent study of severe acute respiratory syndrome coronavirus 2 in pregnancy, patients with a history of melanoma-an indication for examination relatively orthogonal to other problems in pregnancy, and patients paired with PWH using propensity score matching. Results. People living with HIV differ in demographics and comorbidities from comparator groups other than propensity score-matched patients. Placentas from PWH had higher rates of acute placental inflammation, including maternal inflammatory response and fetal inflammatory response, than multiple comparator groups. Placentas from PHW had lower rates of chronic placental inflammation than three of four comparator groups, including the largest comparator group and the group matched to PWH using propensity scores. Conclusion. Differences in placental pathology in PWH depend on the comparator group. Commonly used comparator groups have significantly different demographic and comorbidity profiles, suggesting they are inappropriate comparators for PWH. Propensity score matching may be useful in identifying comparator populations.

Group B streptococcal infections in pregnancy and early life

SUMMARYBacterial infections with Group B Streptococcus (GBS) are an important cause of adverse outcomes in pregnant individuals, neonates, and infants. GBS is a common commensal in the genitourinary and gastrointestinal tracts and can be detected in the vagina of approximately 20% of women globally. GBS can infect the fetus either during pregnancy or vaginal delivery resulting in preterm birth, stillbirth, or early-onset neonatal disease (EOD) in the first week of life. The mother can also become infected with GBS leading to postpartum endometritis, and rarely, maternal sepsis. An invasive GBS infection of the neonate may present after the first week of life (late-onset disease, LOD) through transmission from caregivers, breast milk, and other sources. Invasive GBS infections in neonates can result in sepsis, pneumonia, meningitis, neurodevelopmental impairment, death, and lifelong disability. A policy of routine screening for GBS rectovaginal colonization in well-resourced countries can trigger the administration of intrapartum antibiotic prophylaxis (IAP) when prenatal testing is positive, which drastically reduces rates of EOD. However, many countries do not routinely screen pregnant women for GBS colonization but may administer IAP in cases with a high risk of EOD. IAP does not reduce rates of LOD. A global vaccination campaign is needed to reduce the significant burden of invasive GBS disease that remains among infants and pregnant individuals. In this narrative review, we provide a comprehensive overview of the global impact of GBS colonization and infection, virulence factors and pathogenesis, and current and future prophylactics and therapeutics.

Maternal and Neonatal Infectious Outcomes Compared According to Rupture of Membrane Duration and Antibiotic Administration: A Retrospective Study

BACKGROUND

Prolonged rupture of membranes (ROM) is associated with peripartum infections; the optimal timing to initiate prophylactic antibiotic treatment is inconclusive. We compared maternal and neonatal infectious morbidity and bacterial distribution in chorioamniotic-membrane cultures according to a ROM-to-delivery interval of 12-18 versus ≥18 hours.

METHODS

This retrospective cohort study was conducted in a single tertiary university-affiliated hospital from January 2020 to January 2023. Labor was induced in term singleton pregnant women with ROM ≥12 hours who did not deliver spontaneously within 12-24 hours. Prophylactic ampicillin was administered based on risk factors. Outcomes were compared between ROM 12-18 hours (n = 683) and >18 hours (n = 1039); the latter uniformly received intrapartum antibiotics. The primary maternal outcome was clinical chorioamnionitis. The secondary outcomes included intrapartum fever, cesarean delivery, puerperal endometritis and hospitalization length. Neonatal outcomes included early-onset sepsis, 5-minute Apgar score <7, length of stay, respiratory distress and ventilation support.

RESULTS

The clinical chorioamnionitis rate was comparable between the ROM 12- to 18- and the ≥18-hour groups. However, intrapartum fever occurred more frequently in the former (15.5% vs. 11.6%, P = 0.024), and postoperative infections were significantly higher (11.7% vs. 4.5%, P = 0.020). Cesarean deliveries were more common in ROM ≥18 versus 12-18 hours (21.3% vs. 16.3%, P = 0.028). Neonatal outcomes were similar between the groups. The bacterial distributions among chorioamniotic-membrane cultures were similar, the most common isolated pathogens were Enterobacteriaceae.

CONCLUSIONS

Although the risk of chorioamnionitis was similar, the incidence of intrapartum fever and postoperative infections were higher in ROM 12-18 versus ≥18 hours. Initiating antibiotic prophylactic treatment at 12 hours post-prelabor ROM may be beneficial.

Association between Group B Streptococcus and Clinical Chorioamnionitis by Gestational Week at Delivery-A Multicenter Cohort Study

OBJECTIVE

 In the era of group B Streptococcus (GBS) screening and intrapartum antibiotic prophylaxis (IAP), GBS colonization has been associated with a lower risk of chorioamnionitis, possibly due to a protective effect of IAP. We sought to confirm this finding and assess whether this association varies by gestational week at delivery.

STUDY DESIGN

 We performed a retrospective cohort study of term (37.0-42.6 weeks), singleton parturients with known GBS status who delivered from 2005 to 2021 at two academic medical centers in Israel. We excluded patients who underwent planned cesarean, out of hospital birth, or had a fetal demise. Patients received GBS screening and IAP for GBS positivity as routine clinical care. The primary outcome was a diagnosis of clinical chorioamnionitis as determined by the International Classification of Diseases 10th Revision code, compared between GBS-positive and -negative groups, and assessed by gestational week at delivery.

RESULTS

 Of 292,126 deliveries, 155,255 met inclusion criteria. In total, 30.1% were GBS positive and 69.9% were negative. GBS-positive patients were 21% less likely to be diagnosed with clinical chorioamnionitis than GBS-negative patients, even after controlling for confounders (1.5 vs. 2.2%, adjusted odds ratio: 0.79, 95% confidence interval: 0.68-0.92). When assessed by gestational week at delivery, there was a significantly greater difference in rates of clinical chorioamnionitis between GBS-positive versus GBS-negative groups with advancing gestational age: 1.5-fold difference at 38 to 40 weeks, but a twofold difference at 42 weeks. The risk of clinical chorioamnionitis remained stable in the GBS-positive group, but increased significantly in the GBS-negative group at 41- and 42-week gestation (2.0 vs. 2.9%, p < 0.01 at 41 weeks; up to 3.9% at 42 weeks, p < 0.01).

CONCLUSION

 In a large multicenter cohort with universal GBS screening and IAP, GBS positivity was associated with a lower risk of chorioamnionitis, driven by an increasing rate of chorioamnionitis among GBS-negative patients after 40 weeks.

KEY POINTS

· GBS positivity and IAP may be associated with lower risk of chorioamnionitis.. · GBS-positive patients were less likely to be diagnosed with chorioamnionitis.. · This difference increased with advancing gestational age after 40 weeks..

Sexual activity, vaginal symptoms, maternal perineal hygiene behavior, and constipation on ano-vaginal colonization of group B streptococcus in near term pregnancy

BACKGROUND

Maternal Group B Streptococcus (GBS) colonization is influenced by many factors but results are inconsistent. Consideration of antenatal risk factors may help inform decision making on GBS microbiological culture screening where universal screening is not standard of care. We sought to identify independent predictors of GBS colonization at 34-37 weeks gestation incorporating vaginal symptoms, perineal hygiene measures, sexual activity, and a potential novel factor, constipation.

METHODS

In this prospective cross-sectional study, 573 women at 34-37 weeks gestation had an ano-vaginal swab taken and sent for selective culture for GBS. Women were asked about vaginal bleeding, discharge, irritation and candidiasis, antibiotic use during pregnancy, ano-vaginal hygiene practices such as douching and perineal cleansing after toileting, sexual intercourse related activities, and a potential novel factor for GBS carriage, constipation. Maternal basic demographics and obstetric-related characteristics were also collected. Bivariate analyses were performed to identify associates of GBS colonization. All variables with p < 0.05 found on bivariate analysis were then included into a model for multivariable binary logistic regression analysis to identify independent risk factors for GBS colonization.

RESULTS

GBS colonization was found in 235/573 (41.0%) of participants. Twenty six independent variables were considered for bivariate analysis. Eight were found to have p < 0.05. Following adjusted analysis, six independent predictors of GBS colonization were identified: ethnicity, previous neonatal GBS prophylaxis, antenatal vaginal irritation, antibiotic use, recent panty liner use, and frequency of sexual intercourse. Vaginal discharge and perineal cleansing were not associated after adjustment. Recent douching and constipation were not associated on bivariate analysis.

CONCLUSION

The identification of independent predictors of GBS colonization in late pregnancy may inform the woman and care provider in their shared decision making for microbiological screening at 35-38 weeks gestation in locations where universal GBS screening is not standard of care.

ETHICS OVERSIGHT

This study was approved by the Medical Ethics Committee of University Malaya Medical Centre (UMMC) on August 9, 2022, reference number 2022328-11120.

Association between glycemic control and group B streptococcus colonization among pregnant individuals with pregestational diabetes

PROBLEM

Pregestational diabetes increases the risk of group B streptococcus (GBS) colonization in pregnancy. Whether glycemic control is associated with differences in this risk is unknown. We examined the association between glycemic control and GBS colonization among pregnant individuals with pregestational diabetes.

METHOD OF STUDY

A retrospective cohort of pregnant individuals with pregestational diabetes at a tertiary care center. The exposure was glycemic control, measured as hemoglobin A1c (A1c) at >20 weeks and assessed categorically at thresholds of <6.5% and <6.0%, and secondarily, as a continuous percentage. The outcome was maternal GBS colonization. Multivariable logistic regression was used and adjusted for age, parity, race, and ethnicity as a social determinant, body mass index, type of diabetes, and gestational age at A1c assessment.

RESULTS

Among 305 individuals (33% Type 1, 67% type 2), 45.0% (n = 140) were colonized with GBS. Individuals with an A1c < 6.5% were half as likely to be colonized with GBS compared with those with a A1c ≥ 6.5% (38.8% vs. 53.9%; adjusted odds ratio, AOR: 0.55; 95% CI: 0.33-0.91). Results were unchanged at an A1c threshold of <6.0% (35.7% vs. 48.5%; AOR: 0.60; 95% CI: 0.36-0.98). Individuals with a higher A1c as a continuous measure (%) were more likely to be colonized (AOR: 1.57 per 1%; 95% CI: 1.25-1.97).

CONCLUSIONS

Pregnant individuals with pregestational diabetes with worse glycemic control were at an increased risk of GBS colonization. Further study is needed to understand if improved glycemic control leads to lower risk of GBS colonization.