HISTOLOGICAL CHORIOAMNIONITIS: CURRENT CONCEPTS OF DIAGNOSIS, CLASSIFICATION AND CLINICAL SIGNIFICANCE

An evaluation into the use of procalcitonin levels as a biomarker of bacterial sepsis to aid the management of intrapartum pyrexia and chorioamnionitis

BACKGROUND

Procalcitonin is an established biomarker for bacterial sepsis in the nonpregnant population with better diagnostic and prognostic value for bacterial infections.

OBJECTIVE

This study aimed to evaluate whether procalcitonin levels could be used in the diagnosis and management of intrapartum sepsis in women and their neonates suspected of intrapartum bacterial sepsis.

STUDY DESIGN

A prospective observational cohort study was conducted at the University Hospitals of Bristol and Weston NHS Foundation Trust. Overall, 117 women and their neonates managed for suspected intrapartum sepsis from June 2020 to October 2020 were included. Procalcitonin levels were measured in addition to routine biomarkers white cell count and C-reactive protein in women and their neonates during the initial septic screen and follow-up blood samples. The placentas underwent detailed histopathology. Maternal and neonatal parameters were used to categorize cases into “high-suspicion bacterial sepsis,” “equivocal bacterial sepsis,” and “low-suspicion bacterial sepsis.” The Kruskal-Wallis test was used to compare categories with biomarker values and placental histology scores.

RESULTS

Procalcitonin level was increased in 6 women in the initial septic screen sample, compared with 100 women with an increased C-reactive protein level. There was a significant difference in maternal postnatal procalcitonin results between “high-suspicion bacterial sepsis” and “low-suspicion bacterial sepsis” categories (P=.004). Moreover, 71.2% of placentas showed varying degrees of chorioamnionitis.

CONCLUSION

In our cohort of women, 94.6% had normal procalcitonin levels while in labor at the time of the septic screen, consistent with the low number of confirmed bacteremia. The result provided a basis that procalcitonin may complement clinical judgment and interpretation of already used prognostic and diagnostic tests, improving patient care in the management of intrapartum sepsis.

Acute Villitis and Intravascular Microorganisms in Fetal Vessels: A Case Report and Literature Review of an Unusual Histopathological Finding

Optimal management of intrauterine infection to avoid serious adverse perinatal outcomes entails prompt administration of antibiotics and consideration of early delivery of the fetus to remove the focus of infection. We report an unusual case of preterm chorioamnionitis which did not improve with sensitive antibiotics, or delivery of the fetus, and ultimately required an emergency hysterectomy to save the mother's life. Interestingly, subsequent histopathological analysis of the post-hysterectomy specimen did not reveal myometrial necrosis or infectious microorganisms. The placental pathological examination, on the other hand, showed evidence of necrotising chorioamnionitis accompanied by a rarely reported lesion: acute villitis with abundant intravascular Escherichia coli, a finding which is strongly associated with fetal demise and adverse maternal outcomes.

Fetal vascular malperfusion (FVM): diagnostic implications and clinical associations

INTRODUCTION

Fetal vascular malperfusion (FVM) is diagnosed by the presence of vascular lesions in the muscularized fetal vessels in the placenta and the resultant changes in the downstream villi. The Amsterdam Placental Working Group recognizes two patterns of FVM namely segmental and global. The aim of this study was to estimate the frequency of FVM lesion in our population and to understand its neonatal associations.

METHODS

Fifty-four placentas with FVM and 56 controls collected over 34 months. The maternal and neonatal details were collected from the case charts. The patterns and grades of FVM lesions were related to the clinical factors and significance analyzed statistically using the Chi-square test and t-test and p < .05 was considered significant.

RESULTS

The frequency of FVM was 8.7%. The FVM group showed lower mean gestational age, birth weight, and placental weight with a higher frequency of IUGR. Poor neonatal survival, non-reassuring fetal status, neurological abnormalities, neonatal sepsis, asphyxia, low Apgar, and respiratory support requirement were significantly higher in the FVM group. A similar frequency of segmental and global lesions was seen. High grade lesions (n = 35) were common than low grade (n = 19). Neonatal associations were more often seen in segmental and high-grade lesions.

DISCUSSION

In the absence of antenatal diagnostic tools to identify FVM, placental examination is critical and the only definitive method to diagnose FVM, which alerts the clinician to monitor for several neonatal morbidities. Identification and typing the lesion as per the new guidelines proves significant risk associations with specific types of FVM.

Diagnostic Validity of the Proposed Eunice Kennedy Shriver National Institute of Child Health and Human Development Criteria for Intrauterine Inflammation or Infection

OBJECTIVE

To investigate the test characteristics of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) criteria for intrauterine inflammation or infection or both (triple I) and rates of adverse outcomes in a cohort of febrile intrapartum women.

METHODS

This retrospective cohort study included women at 24 weeks of gestation or greater from June 2015 to September 2017 at a single tertiary hospital with a temperature 100.4°F or greater (38.0°C) during labor or within 1 hour postpartum, all of whom had blood culture data. Women with a fetal demise, expectantly managed preterm prelabor rupture of membranes, or nonobstetric infections were excluded. Documented fever was defined as a single temperature 102.2°F or greater (39.0°C) or a temperature 100.4°F or greater (38.0°C) but less than 102.2°F (39.0°C) on two measurements 45 minutes apart. We defined two analysis groups: 1) suspected triple I, defined as women with documented fever with clinical signs of infection; and 2) isolated maternal fever, defined as women with at least one temperature 100.4°F or greater (38.0°C) who did not meet criteria for suspected triple I. We assessed test characteristics of suspected triple I to predict 1) confirmed triple I, defined as suspected triple I with placental pathology diagnostic of infection; and 2) adverse clinical infectious outcome, defined as a composite of maternal and neonatal adverse infectious outcomes. We also calculated the incidence of adverse clinical infectious outcomes for both groups.

RESULTS

Three hundred thirty-nine women were analyzed: 212 with suspected triple I and 127 with isolated maternal fever. Baseline demographic and obstetric characteristics were similar between groups. The incidence of adverse clinical infectious outcomes was 11.8% among women with suspected triple I and 9.5% among women with isolated maternal fever (P=.50). The sensitivity and specificity of suspected triple I for confirmed triple I were 71.4% (95% CI 61.4-80.1%) and 40.5% (95% CI 33.6-47.8%), respectively, and for an adverse clinical infectious outcome were 67.6% (95% CI 50.2-82.0%) and 38.1% (95% CI 32.6-43.8%), respectively.

CONCLUSION

Applying the NICHD criteria to guide clinical diagnosis and management of intrauterine infection or inflammation may overlook an important proportion of laboring febrile women at risk for adverse infectious outcomes.

Neonatal Morbidities Associated with Histologic Chorioamnionitis Defined Based on the Site and Extent of Inflammation in Very Low Birth Weight Infants

Conflicting results on the influences of histologic chorioamnionitis (HC) on neonatal morbidities might be partly originated from using different definition of HC. The aim of this study was to determine the relationship between HC and neonatal morbidities using definition of HC that reflects the site and extent of inflammation. This was a retrospective cohort study of 261 very low birth weight (VLBW) infants admitted at a tertiary academic center. Based on the site of inflammation, HC was categorized: any HC; amnionitis; funisitis; amnionitis+funisitis. The extent of inflammation in each site was reflected by sub-defining high grade (HG). The incidences of morbidities in infants with and without HC were compared. The bronchopulmonary dysplasia (BPD) rate was significantly higher in infants with amnionitis and the severe retinopathy of prematurity (ROP) rate was significantly higher in infants with any HC and funisitis. After adjustment for both gestational age and birth weight, the respiratory distress syndrome (RDS) rate was significantly lower in infants with all categories of HC except for HG amnionitis and HG funisitis, which are not associated with lower RDS rate. HG amnionitis was significantly associated with increased BPD rate but the association of HC with severe ROP disappeared. In conclusion, HC is significantly associated with decreased RDS and HG amnionitis with increased BPD while lacking association with other neonatal morbidities in VLBW infants. The association with HC and neonatal morbidities differs by the site and extent of chorioamnionitis.

Frozen section of placental membranes and umbilical cord: an aid to early postpartum diagnosis of intra-amniotic infection

OBJECTIVES

We devised a rapid frozen section (FS) assessment technique of placental tissues and performed the first rigorous assessment of FS relative to conventional workup.

METHODS

We evaluated 49 placentas with clinical/gross suspicion of intra-amniotic infection by FS. Relative to formalin-fixed and paraffin-embedded tissues, we compared the grading, staging, and interobserver variability.

RESULTS

FS assessment demonstrated a sensitivity of 0.91 (95% CI, 0.77-0.97) and a specificity of 0.60 (95% CI, 0.36-0.80) for the presence of chorioamnionitis and a sensitivity of 0.89 (95% CI, 0.75-0.96) and a specificity of 0.69 (95% CI, 0.42-0.87) for the presence of funisitis. The χ2 goodness of fit for grade and stage in both placental membrane and umbilical cord sections was significant (P<.001). There was no significant difference in interobserver variability in comparison with permanent section results (P=0.06).

CONCLUSIONS

We conclude that FS is a reasonably sensitive screening technique, correlating well with conventional assessment, without significantly different interobserver variability.