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

Intra-Amniotic Inflammation or Infection: Suspected and Confirmed Diagnosis of "Triple I" at Term

Chorioamnionitis (CA) at term of pregnancy can have an infectious and/or inflammatory origin and is associated with adverse outcomes. Triple I (intrauterine inflammation, infection, or both, TI) has been proposed to reduce the overdiagnosis of infection and neonatal overtreatment. The aim of this study is to identify clinical and histological variables that could predict adverse outcomes when TI is suspected and/or confirmed. This retrospective cohort study included 404 pregnancies (gestational age ≥ 37 weeks) that were divided into 5 all-inclusive and mutually exclusive groups. TI was defined according to the NICHD definition of 2015, and it could be confirmed (TI+) or not confirmed (TI-) via histological examination. Signs of infection/inflammation that did not conform to the definition of TI were classified as "clinical suspicion" and could be supported (CS+) or not supported (CS-) by histology. Cases of histological chorioamnionitis (HCA) without clinical manifestation represented a fifth group. Whole placental involvement (WPLI) was defined as a histological inflammation involving the maternal and fetal sides. There were 113 TI+, 30 TI-, 186 CS+, 35 CS-, and 40 isolated HCA cases. WPLI was diagnosed in 133 cases (39.2%). Composite neonatal outcome (CNO) occurred in 114 cases (28.2%) while composite maternal outcome (CMO) occurred in 192 cases (47.5%). Compared with CS+, TI+ was more predictive of CNO (p = 0.001), CMO (p < 0.001), and WPLI (p = 0.005). WPLI was related both to CNO (p < 0.001) and to CMO (p = 0.046). TI+ and WPLI showed similar sensitivity but different specificity in predicting CNO. At logistic regression, CNO was independently predicted by TI+ (OR 2.21; p = 0.001) and by WPLI (OR 2.23; p = 0.001). Compared with CS, TI is a better predictor of CNO and can be useful for the identification of newborns at risk.

Changing Laboratory Practice for Early Detection of a Fetal Inflammatory Response: A Contemporary Approach

Neonates born with the fetal inflammatory response (FIR) are at risk of complications such as early-onset neonatal sepsis, meningitis, and pneumonia. Providing an early histopathological diagnosis of FIR is important to guide management but can be a challenge in busy laboratories. This is a retrospective cross-sectional study over a four-month duration recruiting all placental cases with histological chorioamnionitis in our institution. The diagnostic performance of the umbilical cord (UC) section in identifying FIR, relative to the corresponding subsequent placental sections, was assessed. Clinical predictors of umbilical cord FIR were also investigated. A total of 390 UC sections were analyzed, of which 206 (52.8%) were found positive for FIR: 111 cases (53.9%) stage 1, 87 (42.2%) stage 2, and 8 (3.9%) stage 3. Our data revealed a good diagnostic sensitivity, specificity, positive predictive value, and accuracy of 76.2% (95%CI: 68.6-82.7%), 82.4% (95%CI: 65.5-93.2%), 95.0% (95%CI: 90.2-97.6%), and 77.3% (95%CI: 70.6-83.1%) respectively, in cases when clinical chorioamnionitis, fever and/or prolonged rupture of membrane (PROM) were suspected, with the area under the curve of 0.793. A maternal inflammatory response (MIR) was correlated with FIR (p < 0.001). Multivariate logistic regression analysis indicated that the higher the gestational age, clinical suspicion of chorioamnionitis, fever, and/or PROM, and the higher the stage of MIR significantly increased the odds of FIR (p < 0.001). UC section diagnosis of FIR is reasonably accurate in cases with clinical chorioamnionitis, fever, and/or PROM. Changing current laboratory practice to rapid processing of UC ahead of the rest of the other placental sections can be recommended in busy pathology departments.

Actualidad en corioamnionitis

La corioamnionitis se ha relacionados con desenlaces desfavorables en el período prenatal y neonatal (abortos, parto pretérmino, sepsis neonatal, entre otros), además de implicaciones a largo plazo en la infancia, tales como alteraciones en el coeficiente intelectual. Por esta razón es de vital importancia el diagnóstico histopatológico oportuno. En este artículo se revisará el abordaje histopatológico de la corioamnionitis, su estadificación e implicaciones clínicas.

Does acute funisitis predict worse neonatal outcomes among term newborns?

BACKGROUND

Acute funisitis-the histologic diagnosis of inflammation within the umbilical cord-represents a fetal inflammatory response to infection. Although acute funisitis has been associated with an increased risk of adverse outcomes among preterm neonates, there are limited and conflicting data with term deliveries.

OBJECTIVE

This study aimed to evaluate the association between acute funisitis and neonatal morbidity in neonates born at term to pregnant patients with a clinical diagnosis of intraamniotic infection.

STUDY DESIGN

This was a retrospective cohort study of pregnant patients who had clinically diagnosed intraamniotic infection at term, delivered vaginally at a single tertiary institution from 2013 to 2019, and had histologic chorioamnionitis on placental pathology. Patients with intrauterine fetal demise or missing neonatal/placental pathology data were excluded. The primary outcome was a neonatal sepsis composite, defined as culture-positive bacteremia, neutropenia (absolute neutrophil count<3500/μL), or immature-to-total neutrophil ratio>0.2. The secondary outcomes included composite neonatal morbidity, defined as neonatal intensive care unit admission, 5-minute Apgar score <7, bacteremia, endotracheal intubation or need for continuous positive airway pressure, intraventricular hemorrhage (grade 3 or 4), necrotizing enterocolitis (stage 3 or 4), umbilical artery pH<7.1, umbilical artery base excess>12, and neonatal mortality. The components of these composites, neonatal intensive care unit length of stay, and Kaiser early-onset sepsis score were also measured. Neonates with acute funisitis on pathology were compared with those without acute funisitis using bivariate statistics. Regression was used to estimate the relative risk of outcomes.

RESULTS

Of 184 neonates with deliveries complicated by intraamniotic infection, acute funisitis was present in 109 (59%) placental specimens. Composite neonatal sepsis was significantly higher among neonates with acute funisitis (relative risk, 1.85; 95% confidence interval, 1.13-3.03) than in those without acute funisitis. As a marker for sepsis, acute funisitis has a sensitivity of 39.4%, negative predictive value of 47.2%, specificity of 78.7%, and positive predictive value of 72.9%. An immature-to-total neutrophil ratio>0.2 (relative risk, 1.83; 95% confidence interval, 1.09-3.08) was also significantly associated with acute funisitis. Neonatal morbidity composite, intraventricular hemorrhage, necrotizing enterocolitis, neonatal intensive care unit admission, higher Kaiser early-onset sepsis scores, and other examined outcomes were not statistically associated with acute funisitis.

CONCLUSION

In term deliveries complicated by intraamniotic infection, acute funisitis was associated with increased neonatal sepsis. Current approaches for estimating neonatal sepsis risk are limited by their reliance on indirect maternal factors such as maximum maternal temperature and intrapartum antibiotic use. This study suggests that acute funisitis may serve as a marker that could be utilized to augment risk stratification at birth if a protocol for evaluating the umbilical cord in real-time were widely adopted.

Acute Funisitis Correlates With the Risk of Early-Onset Sepsis in Term Newborns Assessed Using the Kaiser Sepsis Calculator

BACKGROUND

The risk of neonatal early-onset sepsis (EOS) is traditionally assessed on maternal signs of clinical chorioamnionitis. Recently, an online EOS risk calculator was developed by Kaiser Permanente using maternal and neonatal clinical parameters. We were interested in whether an increased Kaiser sepsis risk score correlates with histologic acute chorioamnionitis or acute funisitis.

DESIGN

Included in this retrospective review are 119 chorioamnionitis-exposed term neonates from January 1, 2015 and December 31, 2016. Clinical charts from mother-baby pairs were reviewed. An EOS risk score was obtained using the online Kaiser Sepsis Calculator. The presence and severity of acute chorioamnionitis and acute funisitis were recorded. A SPSS software was used for statistical analysis (IBM, New Jersey, USA).

RESULTS

The Kaiser Sepsis Calculator could identify 97 of 119 (81.5%) neonates without increased risk for sepsis. Histologic acute chorioamnionitis was present in 100 of 119 cases (84%), in which 44 cases (44%) show severe acute chorioamnionitis. Acute funisitis was recognized in 87 of 119 (73.1%) cases, all of which had concurrent acute chorioamnionitis. Severe funisitis was seen in 38 of the 87 cases (43.7%). The Kaiser Sepsis risk score correlates with the presence and severity of acute funisitis (P = .037 and P = .044, respectively) but not with the presence or the severity of acute chorioamnionitis (P = .105 and P = .672, respectively).

CONCLUSION

Our study provides histological evidence to support that the Kaiser Sepsis Calculator may help to effectively reduce unwarranted blood culture, antibiotics exposure, and neonatal intensive care unit admission in term neonates.

Placental findings in non-hypertensive term pregnancies and association with future adverse pregnancy outcomes: a cohort study

INTRODUCTION

Women with adverse pregnancy outcomes (APOs) have excess risk of later life cardiovascular disease (CVD) perhaps related to an underlying high-risk vascular phenotype. We sought to determine if placental evidence of maternal malperfusion in uncomplicated pregnancies is associated with an increased risk of APOs in subsequent pregnancies.

METHODS

536 women with more than one delivery and an initial uncomplicated pregnancy with placental pathology examination between 2008 and 2012 were included. APOs (small for gestational age, preterm delivery, or preeclampsia) were identified for each delivery. Multivariable log-binomial regression was used to estimate the risk of an APO in a subsequent pregnancy associated with MVM lesions in index pregnancy with adjustment for covariates.

RESULTS

Placental pathology from the initial pregnancy was compared between women with no APO in any pregnancy (-APO/-APO; n = 403) and women with an initial uncomplicated pregnancy and a subsequent adverse outcome (-APO/+APO; n = 133). Women with MVM lesions had an increased risk of an APO in a subsequent pregnancy relative to women with no MVM lesions after adjusting for covariates (aOR = 1.61; 95%CI = 1.06-2.46). Decidual vasculopathy was found in 13/133 (9.8%) of -APO/+APO women compared with 16/403 (4.0%) of -APO/-APO women, with an adjusted odds ratio of 2.51 (95% CI = 1.31-4.80).

DISCUSSION

MVM lesions found in placentas in uncomplicated pregnancies are associated with an increased risk of an adverse outcome in a subsequent pregnancy. Placental evidence of vascular malperfusion could offer a novel approach to risk stratification for subsequent pregnancy complications and perhaps future CVD.

Meconium aspiration syndrome: a role for fetal systemic inflammation

BACKGROUND

Meconium aspiration syndrome (MAS) is a leading cause of morbidity and mortality in term infants. Meconium-stained amniotic fluid (MSAF) occurs in approximately 1 of every 7 pregnancies, but only 5% of neonates exposed to MSAF develop MAS. Why some infants exposed to meconium develop MAS while others do not is a fundamental question. Patients with MSAF have a higher frequency of intraamniotic inflammation/infection than those with clear fluid. We propose that fetal systemic inflammation is a risk factor for the development of MAS in patients with MSAF.

OBJECTIVE

We sought to investigate whether intraamniotic inflammation and funisitis, the histopathologic landmark of a fetal inflammatory response, predispose to MAS.

STUDY DESIGN

A prospective cohort study was conducted from 1995 through 2009. Amniotic fluid (AF) samples (n = 1281) were collected at the time of cesarean delivery from women who delivered singleton newborns at term (gestational age ≥38 weeks). Intraamniotic inflammation was diagnosed if the AF concentration of matrix metalloproteinase-8 was >23 ng/mL. Funisitis was diagnosed by histologic examination if inflammation was present in the umbilical cord.

RESULTS

The prevalence of MSAF was 9.2% (118/1281), and 10.2% (12/118) of neonates exposed to MSAF developed MAS. There were no significant differences in the median gestational age or umbilical cord arterial pH at birth between neonates who developed MAS and those who did not (each P > .1). Mothers whose newborns developed MAS had a higher median of AF matrix metalloproteinase-8 (456.8 vs 157.2 ng/mL, P < .05). Newborns exposed to intraamniotic inflammation had a higher rate of MAS than those who were not exposed to intraamniotic inflammation [13.0% (10/77) vs 0% (0/32), P = .03], as did those exposed to funisitis [31.3% (5/16) vs 7.3% (6/82); relative risk, 4.3; 95% confidence interval, 1.5-12.3]. Among the 89 newborns for whom both AF and placental histology were available, MAS was more common in patients with both intraamniotic inflammation and funisitis than in those without intraamniotic inflammation and funisitis [28.6% (4/14) vs 0% (0/28), P = .009], while the rate of MAS did not show a significant difference between patients with intraamniotic inflammation alone (without funisitis) and those without intraamniotic inflammation and funisitis [10.9% (5/46) vs 0% (0/28)].

CONCLUSION

The combination of intraamniotic inflammation with fetal systemic inflammation is an important antecedent of MAS. This concept has implications for the understanding of the mechanisms of disease responsible for MAS and for the development of prognostic models and therapeutic interventions for this disorder.

Clinical chorioamnionitis at term VI: acute chorioamnionitis and funisitis according to the presence or absence of microorganisms and inflammation in the amniotic cavity

OBJECTIVE

Neonates born to mothers with clinical chorioamnionitis at term are at an increased risk of infection. Acute subchorionitis, chorioamnionitis, and funisitis are considered placental histologic features consistent with acute inflammation according to the Society for Pediatric Pathology. The objectives of this study were to examine the performance of placental histologic features in the identification of: 1) microbial-associated intra-amniotic inflammation (intra-amniotic infection); and 2) fetal inflammatory response syndrome (FIRS).

METHODS

This retrospective cohort study included women with the diagnosis of clinical chorioamnionitis at term (n=45), who underwent an amniocentesis to determine: 1) the presence of microorganisms using both cultivation and molecular biologic techniques [polymerase chain reaction (PCR) with broad range primers]; and 2) interleukin (IL)-6 concentrations by enzyme-linked immunosorbent assay (ELISA). The diagnostic performance (sensitivity, specificity, accuracy, and likelihood ratios) of placental histologic features consistent with acute inflammation was determined for the identification of microbial-associated intra-amniotic inflammation and FIRS.

RESULTS

1) The presence of acute histologic chorioamnionitis and funisitis was associated with the presence of proven intra-amniotic infection assessed by amniotic fluid analysis; 2) funisitis was also associated with the presence of FIRS; 3) the negative predictive value of acute funisitis ≥stage 2 for the identification of neonates born to mothers with intra-amniotic infection was <50%, and therefore, suboptimal to exclude fetal exposure to bacteria in the amniotic cavity; and 4) acute funisitis ≥stage 2 had a negative predictive value of 86.8% for the identification of FIRS in a population with a prevalence of 20%.

CONCLUSION

Acute histologic chorioamnionitis and funisitis are associated with intra-amniotic infection and the presence of FIRS. However, current pathologic methods have limitations in the identification of the fetus exposed to microorganisms present in the amniotic cavity. Further studies are thus required to determine whether molecular markers can enhance the performance of placental pathology in the identification of neonates at risk for neonatal sepsis.