A review of premature birth and subclinical infection

Top-cited articles in the Journal: a bibliometric analysis

BACKGROUND

The Journal has had a profound influence in nearly 150 years of publishing. A bibliometric analysis, which uses citation analyses to evaluate the impact of articles, can be used to identify the most impactful papers in the Journal's history.

OBJECTIVE

The objective was to identify and characterize the top-cited articles published in the Journal since 1920.

STUDY DESIGN

We used the Web of Science and Scopus databases to identify the most frequently cited articles of the Journal from 1920 through 2018. The top 100 articles from each database were included in our analysis. Articles were evaluated for several characteristics including year of publication, article type, topic, open access, and country of origin. Using the Scopus data, we performed an unadjusted categorical analysis to characterize the articles and a 2 time point analysis to compare articles before and after 1995, the median year of publication from each database list.

RESULTS

The top 100 articles from each database were included in the analysis. This included 120 total articles: 80 articles listed in both and 20 unique in each database. More than half (52%) were observational studies, 9% were RCTs, and 75% were from US authors. When the post-1995 studies were compared with the articles published before 1995, articles were more frequently cited (median 27 vs 13 citations per year, P < .001), more likely to be randomized (14.0% vs 4.8%, P = .009), and more likely to originate from international authors (33.3% vs 17.5%, P = .045).

CONCLUSION

Slightly more than half of the top-cited papers in the Journal since 1920 were observational studies and three quarters of all papers were from US authors. Compared with top-cited papers before 1995, the Journal's top-cited papers after 1995 were more likely to be randomized and to originate from international authors.

Pro- and anti-inflammatory effects of sulforaphane on placental cytokine production

Placental inflammation increases the risk of adverse pregnancy outcomes and possibly neurodevelopmental disorders in the offspring. Previous research suggests it may be possible to modulate the placental immune response to bacteria to favor an anti-inflammatory phenotype with dietary factors. Sulforaphane (SFN) is a dietary supplement with known anti-inflammatory activities, however, its effects on placental cytokine production are unclear. Therefore, we evaluated the effects of SFN on biomarkers of inflammation and neurodevelopment under basal conditions and a setting of mild infection. Placental explant cultures were established and treated with up to 10 μM SFN in the presence and absence of 10⁷ CFU/ml heat-killed E. coli. Concentrations of IL-1β, TNF-α, IL-6, sgp130, HO-1 and BDNF in conditioned medium were quantified by immunoassay. SFN increased antioxidant HO-1 expression in the absence, but not the presence, of infection. SFN inhibited IL-1β and IL-10, but tended to promote, TNF-α production by bacteria-stimulated cultures. IL-6 and BDNF were inhibited by SFN irrespective of co-treatment with E.coli. A negative regulator of IL-6 signaling, sgp130, was increased by SFN under basal conditions, but not in E. coli-stimulated cultures. These results suggest that SFN has mixed effects on the placenta inhibiting both pro-inflammatory (IL-1β) and anti-inflammatory factors (IL-10) but promoting regulators of oxidative stress and inflammation (HO-1 and sgp130) in an infection-dependent manner.

Hematological malignancies during pregnancy

Hematological malignancy during pregnancy is a rare event, therefore most data on this issue is based on case studies, retrospective studies and expert opinion. The purpose of the present narrative review was to provide an overview of the diagnosis and recommended management of the most common hematological malignancies during pregnancy, based on current literature, with clinical cases, and discussion of the diagnostic and therapeutic options. The therapeutic consensus while coping with hematological malignancies in pregnancy is to salvage the mother, while trying to preserve pregnancy and avoid treatment-related-toxicity to the fetus. In most scenarios, particularly during late trimesters, the goal is to administer the same treatment as outside of pregnancy, if possible. Further research is needed for better evidence-based management.

[Diagnosis and management of intra-uterine infection: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVE

To determine the diagnosis criteria and management of intra-uterine inflammation or infection (Triple I, III).

METHODS

PubMed and Cochrane Central databases search.

RESULTS

III is defined as an infection of the fetal membranes, and/or other components like the decidua, fetus, amniotic fluid or placenta. This word should be preferred to the word chorioamnionitis that is less precise (Professional consensus). III clinical signs exhibit poor limited sensibility and specificity (EL3). The diagnosis of III is retained in case of maternal fever (defined by a body temperature≥38°C) with no alternative cause identified and at least 2 signs among the following: fetal tachycardia>160 bpm for 10min or longer, uterine pain of labor, purulent fluid from the cervical canal (Professional consensus). Maternal hyperleukocytosis>20 giga/L in the absence of corticosteroids treatment or increased plasmatic C-reactive protein also argue for III, despite their limited sensibility and specificity (EL3). III requires prompt delivery (Grade A). III is not by itself an indication for cesarean delivery (Professional consensus). Antibiotic treatment should cover Streptococcus agalactiae and Escherichia coli. Antibiotics should be started immediately and maintained all over delivery, to reduce neonatal and maternal morbidity (Grade B). Treatment should rely on a combination of betalactamin and aminoglycoside (Grade B). After vaginal delivery, one single dose of antibiotic is required. Antibiotic duration should be longer in case of bacteremia. Longer duration could be considered in case of persistent fever or of cesarean delivery (Professional consensus).

Fetal-placental crosstalk occurs through fetal cytokine synthesis and placental clearance

BACKGROUND

Cytokines modulate fetal well-being and contribute to parturition. Their origin in fetal blood, whether maternal, placental or fetal, at the time of parturition remains unclear.

OBJECTIVE

To determine fetal and placental contributions to circulating fetal cytokines by measuring umbilical arterial (UmA) and venous (UmV) concentration differences in uncomplicated term pregnancies in the absence and presence of labor.

METHODS

Term uncomplicated pregnancies were assessed: Group 1 were not in labor and delivered by elective cesarean section (n = 20); Group 2 delivered vaginally following uncomplicated pregnancy and labor (n = 30). UmA and UmV blood was collected before delivery of the placenta to measure circulating cytokines. Placental tissue was collected for histology and to determine cytokine contents and localization.

RESULTS

Group 1 UmA and UmV IL-10 concentrations were similar (504 ± 15 and 468 ± 16 pg/ml, respectively; P ≥ 0.1); other cytokines were below level of detection. During labor, IL-10 concentrations increased 15-34%, but placental contents decreased. Group 2 UmA IL-6 and IL-8 concentrations increased (P < 0.001) to 16.7 ± 1.6 and 18.4 ± 4.3 pg/ml, respectively, but were less (P < 0.001) in UmV, 0.29 ± 0.2 and 0.74 ± 0.3 pg/ml, respectively, demonstrating placental clearances ≥97%. This was associated with >6-fold increases in placental IL-6/IL-8 contents (P < 0.001) and chorioamniotic infiltration of activated maternal neutrophils. IL-6 and IL-10 were localized to villous syncytiotrophoblasts.

CONCLUSIONS

In uncomplicated term pregnancies fetal circulating IL-10 is likely of placental origin, whereas IL-6/IL-8 are derived from the fetus, increase during parturition, and circulating levels are modulated by non-saturable placental clearance, revealing a novel pathway for fetal-placental crosstalk and signaling.

Efficacy of serum procalcitonin to predict spontaneous preterm birth in women with threatened preterm labour: a prospective observational study

Background

A hypothesis of preterm parturition is that the pathogenesis of spontaneous preterm birth (sPTB) may be associated with an inflammatory process. Based on this theory, we have hypothesized that an inflammatory biomarker, procalcitonin (PCT), may be a good predictive marker of sPTB at the admission for threatened preterm labour (TPL). The present study was aimed to investigate the association between serum PCT and sPTB in women with TPL and to evaluate whether PCT levels may predict sPTB in women with TPL within 7 or 14 days.

Methods

In a prospective observational laboratory-based study, women with singleton pregnancies, TPL between 24 and 36 weeks and intact membranes, were enrolled between January 2014 and June 2016. Participants received routine medical management of TPL (tocolysis with atosiban, antenatal corticosteroids, and biological tests at admission (C-reactive protein, white blood cell count, and PCT measured on electrochemiluminescence immunoassay)). The primary endpoint was sPTB before 37 weeks of gestation. The value of serum PCT levels to predict sPTB within 7 or 14 days were evaluated using receiver-operating curves (ROC) analysis.

Results

A total of 124 women were included in our study. PCT levels did not statistically differ between women with sPTB (n = 30, 24.2%) and controls (n = 94) (median in ng/mL [interquartile range]: 0.043 [0.02–0.07] compared to 0.042 [0.02–0.13], respectively; P = 0.56). PCT levels did not also statistically differ between women with sPTB within 7 days (n = 7, 5.6%) or 14 days (n = 12, 9.7%) after testing and controls. Moreover, subgroup analysis revealed no difference among PCT levels at admission between 24 and 28 weeks, between 28 and 32 weeks and over 32 weeks, and controls. On the basis of the receiver-operating characteristic curve, the highest sensitivity and specificity corresponded to a PCT concentration of 0.038 ng/mL, with poor predictive values for sPTB within 7 or 14 days.

Conclusion

Serum PCT was not relevant to predict sPTB within 7 or 14 days in women admitted with TPL between 24 and 36 weeks, and thus it is not a suitable biological marker to confirm the hypothesis of an inflammatory process associated with preterm parturition.

Trial registration

Clinicaltrials.gov (NCT01977079), Registered 24 October 2013.

Spontaneous preterm birth: advances toward the discovery of genetic predisposition

Evidence from family and twin-based studies provide strong support for a significant contribution of maternal and fetal genetics to the timing of parturition and spontaneous preterm birth. However, there has been only modest success in the discovery of genes predisposing to preterm birth, despite increasing sophistication of genetic and genomic technology. In contrast, DNA variants associated with other traits/diseases have been identified. For example, there is overwhelming evidence that suggests that the nature and intensity of an inflammatory response in adults and children are under genetic control. Because inflammation is often invoked as an etiologic factor in spontaneous preterm birth, the question of whether spontaneous preterm birth has a genetic predisposition in the case of pathologic inflammation has been of long-standing interest to investigators. Here, we review various genetic approaches used for the discovery of preterm birth genetic variants in the context of inflammation-associated spontaneous preterm birth. Candidate gene studies have sought genetic variants that regulate inflammation in the mother and fetus; however, the promising findings have often not been replicated. Genome-wide association studies, an approach to the identification of chromosomal loci responsible for complex traits, have also not yielded compelling evidence for DNA variants predisposing to preterm birth. A recent genome-wide association study that included a large number of White women (>40,000) revealed that maternal loci contribute to preterm birth. Although none of these loci harbored genes directly related to innate immunity, the results were replicated. Another approach to identify DNA variants predisposing to preterm birth is whole exome sequencing, which examines the DNA sequence of protein-coding regions of the genome. A recent whole exome sequencing study identified rare mutations in genes encoding for proteins involved in the negative regulation (dampening) of the innate immune response (eg, CARD6, CARD8, NLRP10, NLRP12, NOD2, TLR10) and antimicrobial peptide/proteins (eg, DEFB1, MBL2). These findings support the concept that preterm labor, at least in part, has an inflammatory etiology, which can be induced by pathogens (ie, intraamniotic infection) or "danger signals" (alarmins) released during cellular stress or necrosis (ie, sterile intraamniotic inflammation). These findings support the notion that preterm birth has a polygenic basis that involves rare mutations or damaging variants in multiple genes involved in innate immunity and host defense mechanisms against microbes and their noxious products. An overlap among the whole exome sequencing-identified genes and other inflammatory conditions associated with preterm birth, such as periodontal disease and inflammatory bowel disease, was observed, which suggests a shared genetic substrate for these conditions. We propose that whole exome sequencing, as well as whole genome sequencing, is the most promising approach for the identification of functionally significant genetic variants responsible for spontaneous preterm birth, at least in the context of pathologic inflammation. The identification of genes that contribute to preterm birth by whole exome sequencing, or whole genome sequencing, promises to yield valuable population-specific biomarkers to identify the risk for spontaneous preterm birth and potential strategies to mitigate such a risk.

The combined exposure to intra-amniotic inflammation and neonatal respiratory distress syndrome increases the risk of intraventricular hemorrhage in preterm neonates

OBJECTIVE

To evaluate the impact of combined exposure to intra-amniotic inflammation and neonatal respiratory distress syndrome (RDS) on the development of intraventricular hemorrhage (IVH) in preterm neonates.

METHODS

This retrospective cohort study includes 207 consecutive preterm births (24.0-33.0 weeks of gestation). Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. According to McMenamin's classification, IVH was defined as grade II or higher when detected by neurosonography within the first weeks of life.

RESULTS

(1) IVH was diagnosed in 6.8% (14/207) of neonates in the study population; (2) IVH was frequent among newborns exposed to intra-amniotic inflammation when followed by postnatal RDS [33% (6/18)]. The frequency of IVH was 7% (8/115) among neonates exposed to either of these conditions - intra-amniotic inflammation or RDS - and 0% (0/64) among those who were not exposed to these conditions; and (3) Neonates exposed to intra-amniotic inflammation and postnatal RDS had a significantly higher risk of IVH than those with only intra-amniotic inflammation [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.1-19.3] and those with RDS alone (OR 5.6, 95% CI 1.0-30.9), after adjusting for gestational age.

CONCLUSION

The combined exposure to intra-amniotic inflammation and postnatal RDS markedly increased the risk of IVH in preterm neonates.

Comparison of rapid MMP-8 and interleukin-6 point-of-care tests to identify intra-amniotic inflammation/infection and impending preterm delivery in patients with preterm labor and intact membranes. J Matern Fetal Neonatal Med 2018;31:228-244. [PMID: 28081646 PMCID: PMC5769687 DOI: 10.1080/14767058.2017.1281904]

OBJECTIVE

Among patients presenting with preterm labor and intact membranes, those with intra-amniotic inflammation have adverse obstetrical and neonatal outcomes. The diagnosis of intra-amniotic inflammation can easily be made by detecting an elevated concentration of the cytokine interleukin (IL)-6 or the enzyme neutrophil collagenase, also known as matrix metalloproteinase (MMP)-8. The diagnostic performances of MMP-8 and IL-6 enzyme-linked immunosorbent assay tests are similar. Recently, a rapid test has become available for point-of-care determination of either MMP-8 or IL-6. The objectives of this study were to compare the diagnostic indices and predictive values between the rapid MMP-8 and IL-6 tests for the identification of intra-amniotic inflammation in patients with preterm labor and intact membranes.

MATERIALS AND METHODS

We performed a retrospective cohort study including 124 women with singleton pregnancies who presented with symptoms of preterm labor and underwent transabdominal amniocentesis for the evaluation of microbial invasion of the amniotic cavity (MIAC). MIAC was defined according to amniotic fluid culture results (aerobic and anaerobic bacteria as well as genital Mycoplasmas). Amniotic fluid white blood cell (WBC) counts were determined using a hemocytometer chamber. An elevated amniotic fluid MMP-8 concentration was assessed using Yoon's MMP-8 Check® (cutoff: 10 ng/mL). An elevated amniotic fluid IL-6 concentration was scored when there was a positive result for the lateral flow-based immunoassay (cutoff: ≥745 pg/mL and ≥1000 pg/mL). In order to objectively compare rapid MMP-8 and rapid IL-6 tests to identify intra-amniotic inflammation, an amniotic fluid WBC count of ≥50 cells/mm3 was used to define intra-amniotic inflammation.

RESULTS

(1) The rapid tests had the same sensitivity for the detection of intra-amniotic inflammation [85.7% (18/21) for all]; (2) the specificity of the rapid MMP-8 test was higher than that of the rapid IL-6 test (cutoff: 745 pg/mL) for the identification of intra-amniotic inflammation [72.8% (75/103) vs. 64.1% (66/103); p < 0.05]; and (3) there were no differences in the sensitivity and specificity between the rapid MMP-8 test and the rapid IL-6 test (cutoff:1000 pg/mL) in the identification of intra-amniotic inflammation. Of 13 patients with discrepant results between the rapid MMP-8 and rapid IL-6 tests, two had a positive MMP-8 but a negative rapid IL-6 test, and both delivered preterm - one within 24 h, and the other within 10 days - and both had acute histologic chorioamnionitis. On the other hand, there were 11 patients with a positive rapid IL-6 but a negative rapid MMP-8 result: 10 delivered preterm, 3 had acute histologic chorioamnionitis and 1 had subacute chorionitis.

CONCLUSION

We conclude that the rapid MMP-8 test has a better specificity than the rapid IL-6 (cutoff: 745 pg/mL) assay for the detection of intra-amniotic infection. Moreover, we observed that among patients who were not identified as having intra-amniotic infection or inflammation by the standard cultivation technique and amniotic fluid WBC count, those who had a positive MMP-8 rapid test delivered preterm and had acute histologic chorioamnionitis.

Cost effects of preterm birth: a comparison of health care costs associated with early preterm, late preterm, and full-term birth in the first 3 years after birth

Preterm birth is one of the main causes for infant morbidity and mortality. Apart from negative health outcomes, preterm birth also produces significant health care expenditures. This study evaluates the costs associated with preterm birth in different health sectors during the first 3 years of infants' lives. In a retrospective observational study based on claims data from a German statutory health insurance company, average costs for medication, hospital treatment, ambulatory treatment, and non-medical remedies during the first 3 years after birth were analyzed for early preterm, late preterm, and full-term births. Costs associated with preterm births were generally higher than for full-term births, with the highest costs for the hospital treatment of early preterm births. Cost differences tended to decrease in the second and third year after birth except for ambulatory treatment costs, which decreased for late preterm and full-term births but not for early preterm births. The study shows that preterm birth is associated with increased health care costs, particularly during the first year after birth, indicating that the implementation of adequate programs and policies for preventing preterm birth is not only desirable from a medical but also from a health economic perspective.

Amniotic fluid neutrophils can phagocytize bacteria: A mechanism for microbial killing in the amniotic cavity

PROBLEM

Neutrophils are capable of performing phagocytosis, a primary mechanism for microbial killing. Intra-amniotic infection is characterized by an influx of neutrophils into the amniotic cavity. Herein, we investigated whether amniotic fluid neutrophils could phagocytize bacteria found in the amniotic cavity of women with intra-amniotic infection.

METHODS

Amniotic fluid neutrophils from women with intra-amniotic infection were visualized by transmission electron microscopy (n=6). The phagocytic activity of amniotic fluid neutrophils from women with intra-amniotic infection and/or inflammation (n=10) or peripheral neutrophils from healthy individuals (controls, n=3) was tested using ex vivo phagocytosis assays coupled with live imaging. Phagocytosis by amniotic fluid neutrophils was also visualized by confocal microscopy (n=10) as well as scanning and transmission electron microscopy (n=5).

RESULTS

(i) Intra-amniotic infection-related bacteria including cocci (eg Streptococcus agalactiae), bacilli (eg Bacteriodes fragilis and Prevotella spp.), and small bacteria without a cell wall (eg Ureaplasma urealyticum) were found inside of amniotic fluid neutrophils; (ii) peripheral neutrophils (controls) rapidly phagocytized S. agalactiae, U. urealyticum, Gardnerella vaginalis, and Escherichia coli; (iii) amniotic fluid neutrophils rapidly phagocytized S. agalactiae and G. vaginalis; and (iv) amniotic fluid neutrophils slowly phagocytized U. urealyticum and E. coli; yet, the process of phagocytosis of the genital mycoplasma was lengthier.

CONCLUSION

Amniotic fluid neutrophils can phagocytize bacteria found in the amniotic cavity of women with intra-amniotic infection, namely S. agalactiae, U. urealyticum, G. vaginalis, and E. coli. Yet, differences in the rapidity of phagocytosis were observed among the studied microorganisms. These findings provide a host defense mechanism whereby amniotic fluid neutrophils can kill microbes invading the amniotic cavity.

A Role for the Inflammasome in Spontaneous Preterm Labor With Acute Histologic Chorioamnionitis

Inflammasomes are cytosolic multiprotein complexes that orchestrate inflammation in response to pathogens and endogenous danger signals. Herein, we determined whether the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis (1) express major inflammasome components; (2) express caspase (CASP)-1 and CASP-4 as well as their active forms; (3) exhibit apoptosis-associated speck-like protein containing a CARD (ASC)/CASP-1 complex formation; and (4) release the mature forms of interleukin (IL)-1β and IL-18. We utilized quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, immunoblotting, and immunohistochemistry to determine the messenger RNA (mRNA) and protein expression of major inflammasome components, nucleotide-binding oligomerization domain (NOD) proteins, and the pro- and mature/active forms of CASP-1, CASP-4, IL-1β, and IL-18. The ASC/CASP-1 complex formation was determined using an in situ proximity ligation assay. When comparing the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis to those without this placental lesion, we found that (1) the mRNA of NLR family pyrin domain-containing protein ( NLRP) 1, NLRP3, NLR family CARD domain-containing protein 4 ( NLRC4), and NOD2 were higher; (2) the NLRP3 protein was increased; (3) the mRNA and active form (p10) of CASP-1 were greater; (4) the mRNA and active form of CASP-4 were increased; (5) the mRNA and mature form of IL-1β were higher; (6) the mature form of IL-18 was elevated; and (7) ASC/CASP-1 complex formation was increased. In conclusion, spontaneous preterm labor with acute histologic chorioamnionitis is characterized by an upregulation of NLRP3 and the active form of CASP-4, as well as increased ASC/CASP-1 complex formation, which may participate in the activation of CASP-1 and the maturation of IL-1β and IL-18 in the chorioamniotic membranes. These findings provide the first evidence that supports a role for the inflammasome in the pathological inflammation implicated in spontaneous preterm labor with acute histologic chorioamnionitis.

The cytokine network in women with an asymptomatic short cervix and the risk of preterm delivery

PROBLEM

To characterize the amniotic fluid (AF) inflammatory-related protein (IRP) network in patients with a sonographic short cervix (SCx) and to determine its relation to early preterm delivery (ePTD).

METHOD OF STUDY

A retrospective cohort study included women with a SCx (≤25 mm; n=223) who had amniocentesis and were classified according to gestational age (GA) at diagnosis and delivery (ePTD <32 weeks of gestation).

RESULTS

(i) In women with a SCx ≤ 22 1/7 weeks, the concentration of most IRPs increased as the cervix shortened; those with ePTD had a higher rate of increase in MIP-1α, MCP-1, and IL-6 concentrations than those delivering later; and (ii) the concentration of most IRPs and the correlation between several IRP pairs were higher in the ePTD group than for those delivering later.

CONCLUSION

Women with a SCx at 16-22 1/7 weeks have a unique AF cytokine network that correlates with cervical length at diagnosis and GA at delivery. This network may aid in predicting ePTD.

Clinical chorioamnionitis at term VII: the amniotic fluid cellular immune response

OBJECTIVES

1) To characterize the cellular composition of the amniotic fluid of patients diagnosed with clinical chorioamnionitis at term, as a function of the presence or absence of microorganisms determined by cultivation techniques, and 2) to characterize the cytokine production by white blood cells present in the amniotic fluid using flow cytometry-based techniques.

MATERIALS AND METHODS

Amniotic fluid samples from 20 women who had the diagnosis of clinical chorioamnionitis at term were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital Mycoplasmas). Amniotic fluid IL-6 concentrations were determined by an enzyme-linked immunosorbent assay. Amniotic fluid leukocytes were visualized by using hematoxylin and eosin staining and immunofluorescence. Immunophenotyping of surface markers and cytokines was performed in amniotic fluid leukocytes using flow cytometry.

RESULTS

1) Neutrophils (CD45+CD15+ cells) were the most common leukocyte subset found in the amniotic fluid, followed by monocytes (CD45+CD14+ cells); other white blood cells (such as lymphocytes and natural killer cells) were scarce in the amniotic fluid; 2) the absolute counts of neutrophils and monocytes were significantly higher in patients with microorganisms found in the amniotic fluid than in those without detectable microorganisms, using cultivation techniques; 3) there was a significant correlation between the absolute counts of neutrophils and monocytes determined by flow cytometry (Spearman's correlation=0.97; P<0.001); 4) there was a significant correlation between the absolute white blood cell count determined with a hemocytometer chamber and by flow cytometric analysis (Spearman's correlation=0.88; P<0.001); and 5) the profile of cytokine expression differed between monocytes and neutrophils; while neutrophils predominantly produced TNF-α and MIP-1β, monocytes expressed higher levels of IL-1β and IL-1α.

CONCLUSION

Flow cytometry analysis of the amniotic fluid of patients with intra-amniotic infection and clinical chorioamnionitis at term demonstrated that neutrophils and monocytes are the most common cells participating in the inflammatory process. We have characterized, for the first time, the differential cytokine expression by these cells in this important complication of pregnancy.

The Association between Periodontal Disease and Preterm Low Birthweight in Kosovo

OBJECTIVE

Periodontal diseases have a high prevalence worldwide. Existing evidence support the concept that gingivitis and periodontitis are potentially infectious and they present inflammatory reservoirs that can be threatening to the fetoplacental unit. The objective of this study was to compare the periodontal status between women with normal delivery and those with preterm low-birthweight delivery.

MATERIALS AND METHODS

This study included 200 postpartum women whose periodontal and obstetrical parameters were taken. The periodontal condition was assessed bedside according to the modified criteria established by Machtei, while the birthweight and gestational age were assessed according to the World Health Organization criteria.

RESULTS

Women with periodontitis are statistically at 3.2 times higher risk to deliver a child with low weight, and at 3.4 times higher risk to deliver preterm, compared to women without periodontitis. The women with preterm low-birthweight babies had deeper periodontal pockets (2.49mm ± 0.49mm) than women with normal delivery (2.26mm ± 0.49mm).

CONCLUSIONS

Periodontal disease in pregnant women with a reservoir of organisms and their products can be considered a risk factor for adverse pregnancy outcome.

Intra-amniotic administration of lipopolysaccharide induces spontaneous preterm labor and birth in the absence of a body temperature change

OBJECTIVE

Intra-amniotic infection is associated with spontaneous preterm labor. In most cases, the infection is subclinical and bacteria are detected in the amniotic cavity rather than in the chorioamniotic membranes. The aims of this study were to establish a model of intra-amniotic lipopolysaccharide (LPS)-induced preterm labor/birth that resembles the subclinical syndrome and to compare this model to two established models of LPS-induced preterm labor/birth.

METHODS

Pregnant B6 mice received an intra-amniotic, intra-uterine, or intra-peritoneal injection of LPS (100 ng/amniotic sac, 15 μg/25 μL, and 15 μg/200 μL respectively) or PBS (control). Following injection, body temperature (every two hours for a 12-h period), gestational age, and the rate of preterm labor/birth were recorded.

RESULTS

An intra-amniotic injection of LPS resulted in preterm labor/birth [LPS 80 ± 24.79% (8/10) versus PBS 0% (0/8); p = 0.001] without causing maternal hypothermia. Intra-peritoneal [LPS 100% (8/8) versus PBS 0% (0/8); p < 0.001)] and intra-uterine [LPS 100% (8/8) versus PBS 28.57 ± 33.47% (2/7); p =0 .007] injections of LPS induced preterm labor/birth; yet, maternal hypothermia was observed.

CONCLUSION

Intra-amniotic injection of LPS induces preterm labor/birth in the absence of a body temperature change, which resembles the subclinical syndrome.

The Microbiome and Complement Activation: A Mechanistic Model for Preterm Birth

Preterm birth (PTB, <37 completed weeks' gestation) is one of the leading obstetrical problems in the United States, affecting approximately one of every nine births. Even more concerning are the persistent racial disparities in PTB, with particularly high rates among African Americans. There are several recognized pathophysiologic pathways to PTB, including infection and/or exaggerated systemic or local inflammation. Intrauterine infection is a causal factor linked to PTB thought to result most commonly from inflammatory processes triggered by microbial invasion of bacteria ascending from the vaginal microbiome. Trials to treat various infections have shown limited efficacy in reducing PTB risk, suggesting that other complex mechanisms, including those associated with inflammation, may be involved in the relationship between microbes, infection, and PTB. The complement system, a key mediator of the inflammatory response, is an innate defense mechanism involved in both normal physiologic processes that occur during pregnancy implantation and processes that promote the elimination of pathogenic microbes. Recent research has demonstrated an association between this system and PTB. The purpose of this article is to present a mechanistic model of inflammation-associated PTB, which hypothesizes a relationship between the microbiome and dysregulation of the complement system. Exploring the relationships between the microbial environment and complement biomarkers may elucidate a potentially modifiable biological pathway to PTB.

Inflammatory Stimuli Increase Progesterone Receptor-A Stability and Transrepressive Activity in Myometrial Cells

The steroid hormone progesterone acting via the nuclear progesterone receptor (PR) isoforms, progesterone receptor A (PR-A) and progesterone receptor B (PR-B), is essential for the maintenance of uterine quiescence during pregnancy. Inhibition of PR signaling augments uterine contractility and induces labor. Human parturition is thought to be triggered by modulation of PR signaling in myometrial cells to induce a functional progesterone withdrawal. One mechanism for functional progesterone withdrawal is increased abundance of PR-A, which decreases progesterone responsiveness by inhibiting the transcriptional activity of PR-B. Human parturition also involves tissue-level inflammation within the myometrium. This study examined the control of PR-A abundance and transrepressive activity in myometrial cells and the role of the inflammatory stimuli in the form of interleukin-1β (IL-1β) and lipopolysaccharide (LPS) in these processes. We found that abundance of PR-A was markedly increased by progesterone and by exposure to IL-1β and LPS via posttranslational mechanisms involving increased PR-A protein stability. In contrast, progesterone decreased abundance of PR-B by increasing its rate of degradation. Together, progesterone and proinflammatory stimuli induced a PR-A-dominant state in myometrial cells similar to that observed in term laboring myometrium. IL-1β and LPS also increased the capacity for PR-A to inhibit the transcriptional activity of PR-B. Taken together, our data suggest that proinflammatory stimuli increase the steady-state levels of PR-A and its transrepressive activity in myometrial cells and support the hypothesis that tissue-level inflammation triggers parturition by inducing PR-A-mediated functional progesterone withdrawal.

Genital tract microbial isolate in women with preterm pre-labour rupture of membranes in resource-constrained community setting

This study determined patterns of microbial isolates in genital tract of women with preterm pre-labour rupture of membranes (PPROM) compared with cases without PPROM. Endocervical swabs of women with confirmed diagnosis of PPROM were examined microbiologically and compared in blinded pattern with gestational-age-matched controls. One hundred and five microbiological results each for cases and controls were analysed. Positive microbial cultures were seen in 79.05% of cases versus 6.67% of controls. Streptococcus spp. (31.43%) was the commonest organism isolated in cases (p < 0.001), while Candida albicans was significantly more in controls (p < 0.001). The highest incidence of PPROM (82.86%) occurred in gestational ages of 28-30 and 34-36 weeks. No fewer than 75.24% cases occurred in low parity (0-2). Majority occurred in extremes of viable preterm gestation and in women of low parity.

Evaluation of Human Papillomavirus as a Risk Factor for Preterm Birth or Pregnancy-Related Hypertension

OBJECTIVE

To compare rates of preterm birth and pregnancy-related hypertension in women with and without human papillomavirus (HPV) infection.

METHODS

We performed a retrospective cohort study of all women delivered at our institution in 2013 who had cervical cancer screening test results within 3 years before delivery. Patients were excluded if they had prior procedure(s) for cervical dysplasia other than biopsy. There were two primary outcomes: preterm birth (less than 37 weeks of gestation) and pregnancy-related hypertension (gestational hypertension, preeclampsia, or eclampsia). Multivariable logistic regression was performed to adjust for confounders including demographic variables, diabetes, prior preterm birth, chronic hypertension, and other genital infections. Assuming a 10% prevalence of HPV, a rate of 12% in the HPV-negative group for both preterm birth and pregnancy-related hypertension, α of 0.05, and β of 0.2, we needed 2,207 patients to detect a 60% increase in the rate of either outcome in the HPV-positive group.

RESULTS

A total of 3,958 patients delivered in 2013, of whom 2,321 met eligibility criteria, 242 (10.4%) of whom were HPV-positive and 2,079 (89.2%) of whom were HPV-negative. In multivariate analyses, the rate of preterm birth was not significantly different between HPV-positive and HPV-negative women (16.5% compared with 12.2%, adjusted odds ratio [OR] 1.3, 95% confidence interval [CI] 0.9-1.9); rates of pregnancy-related hypertension also were not significantly different between HPV-positive and HPV-negative women (17.0% compared with 16.4%, adjusted OR 1.0, 95% CI 0.7-1.5).

CONCLUSION

Maternal HPV infection is not an independent risk factor for preterm birth or pregnancy-related hypertension.

Lipidomic analysis of patients with microbial invasion of the amniotic cavity reveals up-regulation of leukotriene B4

Bioactive lipids derived from the metabolism of polyunsaturated fatty acids are important mediators of the inflammatory response. Labor per se is considered a sterile inflammatory process. Intra-amniotic inflammation (IAI) due to microorganisms (i.e., intra-amniotic infection) or danger signals (i.e., sterile IAI) has been implicated in the pathogenesis of preterm labor and clinical chorioamnionitis at term. Early and accurate diagnosis of microbial invasion of the amniotic cavity (MIAC) requires analysis of amniotic fluid (AF). It is possible that IAI caused by microorganisms is associated with a stereotypic lipidomic profile, and that analysis of AF may help in the identification of patients with this condition. To test this hypothesis, we analyzed the fatty acyl lipidome of AF by liquid chromatography-mass spectrometry from patients in spontaneous labor at term and preterm gestations. We report that the AF concentrations of proinflammatory lipid mediators of the 5-lipoxygenase pathway are significantly higher in MIAC than in cases of sterile IAI. These results suggest that the concentrations of 5-lipoxygenase metabolites of arachidonic acid, 5-hydroxyeicosatetraenoic acid, and leukotriene B4 in particular could serve as potential biomarkers of MIAC. This finding could have important implications for the rapid identification of patients who may benefit from anti-microbial treatment.-Maddipati, K. R., Romero, R., Chaiworapongsa ,T., Chaemsaithong, P., Zhou, S.-L., Xu, Z., Tarca, A. L., Kusanovic, J. P., Gomez, R., Chaiyasit, N., Honn, K. V. Lipidomic analysis of patients with microbial invasion of the amniotic cavity reveals up-regulation of leukotriene B4.

Periodontitis, cardiovascular disease and pregnancy outcome--focal infection revisited?

Over the last two decades there has been a renewed interest around the possible effects of periodontal disease on both cardiovascular health and pregnancy outcome (among other diseases), a topic which has interested science for hundreds of years. These have led to a range of studies, workshops and consensus documents being published, with corresponding coverage in general and professional media. In this article the authors summarise the history and supporting theories behind such associations, whether clinical studies have been able to confirm these and what this might mean for general practitioners who are questioned on this topic by patients.

Clinical chorioamnionitis at term: the amniotic fluid fatty acyl lipidome

Clinical chorioamnionitis at term (TCC) is the most common obstetrical infliction diagnosed in labor and delivery units worldwide and is associated with a substantial increase in maternal and neonatal morbidity and mortality. This obstetrical complication is a heterogeneous condition, as only half of patients have detectable microorganisms in the amniotic cavity. Because bioactive lipids play a key role in the initiation and resolution of an inflammatory response, we aimed to characterize the amniotic fluid lipidome in patients with TCC. We studied the amniotic fluid of patients in the following groups: 1) spontaneous labor at term without clinical chorioamnionitis (TLB) and 2) spontaneous labor at term with clinical chorioamnionitis (TCC). The TCC group was subdivided into a) those with microbial invasion of the amniotic cavity (TCC-MIAC) and b) those without microbial invasion of the amniotic cavity (TCC-noMIAC). The amniotic fluid concentration of proinflammatory lipid mediators did not differ between patients in TLB with TCC. In contrast, concentration of lipids with anti-inflammatory/proresolution properties was significantly lower in all patients with TCC than in those with TLB. These results suggest that while proinflammatory lipid mediators are involved in infection-driven intra-amniotic inflammation, a relative deficiency of anti-inflammatory/proresolution lipid mediator biosynthesis is a characteristic of TCC.

Microbial Changes during Pregnancy, Birth, and Infancy

Several healthy developmental processes such as pregnancy, fetal development, and infant development include a multitude of physiological changes: weight gain, hormonal, and metabolic changes, as well as immune changes. In this review, we present an additional important factor which both influences and is affected by these physiological processes-the microbiome. We summarize the known changes in microbiota composition at a variety of body sites including gut, vagina, oral cavity, and placenta, throughout pregnancy, fetal development, and early childhood. There is still a lot to be discovered; yet several pieces of research point to the healthy desired microbial changes. Future research is likely to unravel precise roles and mechanisms of the microbiota in gestation; perhaps linking the metabolic, hormonal, and immune changes together. Although some research has started to link microbial dysbiosis and specific microbial populations with unhealthy pregnancy complications, it is important to first understand the context of the natural healthy microbial changes occurring. Until recently the placenta and developing fetus were considered to be germ free, containing no apparent microbiome. We present multiple study results showing distinct microbiota compositions in the placenta and meconium, alluding to early microbial colonization. These results may change dogmas and our overall understanding of the importance and roles of microbiota from the beginning of life. We further review the main factors shaping the infant microbiome-modes of delivery, feeding, weaning, and exposure to antibiotics. Taken together, we are starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points.

Periodontal status in Taiwanese pregnant women

BACKGROUND/PURPOSE

Few studies have investigated the periodontal status of Taiwanese pregnant women. This study aimed to investigate the periodontal status of pregnant women and to examine its relation to oral hygiene.

MATERIAL AND METHODS

This study randomly recruited 477 pregnant women. Among them, 203 women were in their first trimester. Forty-six women completed the study to the end of their third trimester. We also recruited 160 nonpregnant women as the control group. Clinical periodontal parameters were recorded and included probing pocket depth [PPD (mm)], clinical attachment level [CAL (mm)], gingival index simplified [GI-s (%)], and plaque index [PI (%)].

RESULTS

The GI-s of the pregnant group (PG) was higher than that of the control group [CG; (i.e., nonpregnant)], but only the third trimester was statistically significantly different (P < 0.001).The full mouth dental PI was higher in the PG than in the CG (P < 0.001), particularly in the interproximal areas. The mean PPD was greater in the PG than in the CG (P < 0.001) in all tooth areas. The mean CAL was higher in the PG than in the CG (P < 0.001), but no difference existed between the different trimesters. The CG had a higher percentage of sites with a shallow PPD, compared to the PG (P < 0.001); the PG had a higher percentage of sites with a PPD of 4-6 mm, compared to the CG (P < 0.001). Only the PI of the full mouth and lingual tooth surfaces in the third trimester were better than in the first trimester throughout the pregnancy.

CONCLUSION

Gingival inflammation in pregnant women is positively correlated with the increased deposition of a dental plaque biofilm.

[Update in family medicine: Periodontal disease]

About 85-94% of the Spanish adults older than 35 experience gum problems, and about 15-30% suffer from periodontitis, being severe in up to 5-11% of them. Unlike other inflammatory conditions, periodontal disease rarely causes discomfort, or limits life or causes functional limitations until its advanced stages, when clinical signs and symptoms arise (gingival recession, pathological teeth migration, or mobility). Lack of knowledge about the disease, together with the idea that tooth loss is linked to ageing, frequently results in a late diagnosis, requiring extensive treatments with a worse prognosis. At Primary Care level, there is series of drugs have been related to periodontal disease (anticonvulsants, immunosuppressive drugs, and calcium channel blockers) as secondary effects, which vary as regards their frequency and severity depending of the amount of accumulated plaque. Stress and depression have also been reported to alter the immune response and to increase the inflammatory response as well as periodontal susceptibility. Certain systemic conditions, such as diabetes mellitus, cardiovascular disorders, respiratory diseases, as well as low-weight pre-term birth, have also been linked to periodontitis.

Maternal microbiome - A pathway to preterm birth

Despite great medical advances in preventing maternal and infant mortality in the past century, one issue remains unresolved: why do so many women give birth prematurely? A major new field of human microbiome studies has begun to shed light on the impact of microbes (of both the commensal and pathogen varieties) on pregnancy outcomes. Recent advances in next-generation sequencing and metagenomic analysis have revealed that maternal microbiomes at a variety of niches including the oral, vaginal, gut, cervical, and even the placenta itself govern pregnancy outcomes. In this review, we describe how alterations in the microbial biomasses impact preterm birth and we discuss the major research questions concerning the cause and/or interdependent relationships between microbiome, infection, and preterm delivery.

The relationship of circulating proteins in early pregnancy with preterm birth

BACKGROUND

Preterm birth (PTB) (< 37 completed weeks' gestation) is a pathological outcome of pregnancy and a major global health problem. Babies born preterm have an elevated risk for long-term adverse medical and neurodevelopmental sequelae. Substantial evidence implicates intrauterine infection and/or inflammation in PTB. However, these are often relatively late findings in the process, when PTB is inevitable. Identification of earlier markers of PTB may make successful intervention possible. Although select proteins, notably those related to the inflammatory pathways, have been associated with PTB, there has been a lack of research into the role of other protein pathways in the development of PTB. The purpose of this study was to investigate, using a previously described biomarker discovery approach, a subset of circulating proteins and their association with PTB focusing on samples from early pregnancy.

OBJECTIVES

The objectives of the study were as follows: (1) to perform a large-scale biomarker discovery, utilizing an innovative platform to identify proteins associated with preterm birth in plasma taken between 10 and 15 weeks' gestation and, (2) to determine which protein pathways are most strongly associated with preterm birth. To address these aims, we measured 1129 proteins in a plasma sample from early pregnancy using a multiplexed aptamer-based proteomic technology developed in Colorado by SomaLogic.

STUDY DESIGN

Using a nested case-control approach, we measured proteins at a single time point in early pregnancy in 41 women who subsequently delivered preterm and 88 women who had term uncomplicated deliveries. We measured 1129 proteins using a multiplexed aptamer-based proteomic technology developed by SomaLogic. Logistic regressions and random forests were used to compare protein levels.

RESULTS

The complement factors B and H and the coagulation factors IX and IX ab were the highest-ranking proteins distinguishing cases of preterm birth from term controls. The top 3 pathways associated with preterm birth were the complement cascade, the immune system, and the clotting cascade.

CONCLUSION

Using a discovery approach, these data provide further confirmation that there is an association of immune- and coagulation-related events in early pregnancy with preterm birth. Thus, plasma protein profiles at 10-15 weeks of gestation are related to the development of preterm birth later in pregnancy.

What is the optimal strategy in the management of patients with preterm premature rupture of membranes before 32 weeks of gestation?

Objective:

Our aim was to compare the outcomes of expectant management of pregnancy or immediate delivery in patients with preterm premature rupture of membranes (PPROM) between 24+⁰ and 32+⁰ weeks of pregnancy.

Materials and Methods:

This is a retrospective cohort study conducted at a tertiary medical center. Patients who were diagnosed as having PPROM between 24+⁰ and 32+⁰ weeks of gestation were selected from an electronic database. Thirty-one patients with expectant management and 22 patients with spontaneous immediate delivery were analyzed. Birth weight, Apgar score, duration of stay in the neonatal intensive care unit (NICU), composite adverse outcomes, and mortality rates of groups were compared. Binary logistic regression analysis with backward stepwise elimination was used to determine confounding factors for antenatal complications and neonatal composite adverse outcomes.

Results:

Gestational age at admission was smaller in the expectant management group. The median latency period was 6 days (range, 2-58 days). Although gestational age at delivery was similar, birth weights were smaller in expectant management group compared with the immediate delivery group (p=0.264 and p<0.05, respectively). Apgar scores, duration in the NICU, composite adverse outcomes, and neonatal mortality rates were similar in each group. Antenatal complication in the expectant management group was higher (p<0.05). Gestational age at delivery and serum C-reactive protein levels were two confounding factors for antenatal complication and gestational age at delivery was the only factor affecting composite adverse outcome.

Conclusion:

Expectant management in patients with PPROM at 24 to 32 gestational weeks might be considered as a good alternative.

Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile

INTRODUCTION

Fever is a major criterion for clinical chorioamnionitis; yet, many patients with intrapartum fever do not have demonstrable intra-amniotic infection. Some cytokines, such as interleukin (IL)-1, IL-6, interferon-gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α), can induce a fever. The objective of this study was to determine whether maternal plasma concentrations of cytokines could be of value in the identification of patients with the diagnosis of clinical chorioamnionitis at term who have microbial-associated intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=41; cases) and women in spontaneous labor at term without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified into three groups according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), and amniotic fluid IL-6 concentration: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. The maternal plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) The maternal plasma concentrations of pyrogenic cytokines (IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) were significantly higher in patients with clinical chorioamnionitis at term than in those with spontaneous term labor without clinical chorioamnionitis; 2) the maternal plasma concentrations of cytokines were not significantly different among the three subgroups of patients with clinical chorioamnionitis (intra-amniotic inflammation with and without detectable bacteria and those without intra-amniotic inflammation); and 3) among women with the diagnosis of clinical chorioamnionitis, but without evidence of intra-amniotic inflammation, the maternal plasma concentrations of pyrogenic cytokines were significantly higher than in patients with spontaneous labor at term. These observations suggest that a fever can be mediated by increased circulating concentrations of these cytokines, despite the absence of a local intra-amniotic inflammatory response.

CONCLUSIONS

1) The maternal plasma concentrations of pyrogenic cytokines (e.g. IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) are higher in patients with intra-partum fever and the diagnosis of clinical chorioamnionitis at term than in those in spontaneous labor at term without a fever; and 2) maternal plasma cytokine concentrations have limited value in the identification of patients with bacteria in the amniotic cavity. Accurate assessment of the presence of intra-amniotic infection requires amniotic fluid analysis.

Enhanced Expression of Contractile-Associated Proteins and Ion Channels in Preterm Delivery Model Mice With Chronic Odontogenic Porphyromonas Gingivalis Infection

Inflammation and infection have been reported to induce preterm delivery. We have studied the relationship between inflammation and various ion channels, including the L-type Ca(2+) channel and P2X7 receptor, during acute inflammation of the pregnant rat uterus induced by lipopolysaccharides. Recently, we found that mice with odontogenic Porphyromonas gingivalis (P.g, an important odontogenic pathogen) infection delivered at day 18.3 of gestation (vs. day 20.5 in normal mice). The purpose of this study was to investigate the expression of myometrial contractile-associated proteins inducing contractions and confirm that these mice are useful as a model for preterm delivery induced by chronic inflammation. We examined the expression of the oxytocin receptor, connexin 43, prostaglandin F receptors, L-type Ca(2+) channel, and P2X7 receptor in the myometrium at day 18 of gestation by real-time PCR and western blot analyses. We also measured TNF-α and IL-1β levels in the blood serum, placenta, fetal membrane and myometrium on the same day. mRNA expression of the oxytocin receptor, connexin 43, prostaglandin F receptors, L-type Ca(2+) channel, and P2X7 receptor was elevated by 5.4, 3.2, 2.4, 2.5, and 1.7 fold, respectively, in the P.g-infected mice. Protein levels of the oxytocin receptor and connexin 43 also increased. Serum levels of TNF-α and IL-1β were elevated, showing that systemic inflammation continued during pregnancy. IL-1β levels in the placenta and fetal membrane also increased, suggesting inflammatory reactions were induced. Thus, mice with odontogenic infection may be useful as a model of chronic inflammation-induced preterm delivery.

About one-half of early spontaneous preterm deliveries can be identified by a rapid matrix metalloproteinase-8 (MMP-8) bedside test at the time of mid-trimester genetic amniocentesis

OBJECTIVE

Mid-trimester amniocentesis continues to be used for the prenatal diagnosis of chromosomal anomalies and other genetic disorders. Analysis of amniotic fluid obtained at the time of mid-trimester genetic amniocentesis identifies those patients who are at risk for early spontaneous preterm delivery. This is based on a solid body of evidence that found subclinical intra-amniotic inflammation/infection to be causally linked to early spontaneous preterm birth. Although several biomarkers have been proposed to identify intra-amniotic inflammation, the accumulated data suggest that the determination of amniotic fluid matrix metalloproteinase-8 (MMP-8), or neutrophil collagenase, is a powerful predictor of spontaneous preterm delivery. MMP-8 is released by inflammatory cells in response to microbial products or "danger signals". A rapid point-of-care test has been developed to determine MMP-8 at the bedside within 20 min, and without the requirement of laboratory equipment. The objective of this study was to determine whether an elevation of MMP-8 in the amniotic fluid, measured by a rapid point-of-care test, can identify those patients at risk for spontaneous preterm delivery after a mid-trimester genetic amniocentesis.

STUDY DESIGN

A case-control study was designed to obtain amniotic fluid from asymptomatic singleton pregnant women who underwent mid-trimester genetic amniocentesis. An MMP-8 bedside test was performed to analyze the amniotic fluid of 64 patients with early spontaneous preterm delivery (<30 weeks) and 128 matched controls with normal pregnancy outcomes.

RESULTS

(1) The MMP-8 bedside test (Yoon's MMP-8 Check™) was positive in 42.2% (27/64) of patients with spontaneous preterm delivery but in none (0/128) of the control cases (p < 0.001); (2) the MMP-8 bedside test had a sensitivity of 42.2%, and a specificity of 100% in the prediction of spontaneous preterm delivery (<30 weeks) following a mid-trimester genetic amniocentesis; and (3) among the patients with spontaneous preterm delivery, those with a positive MMP-8 bedside test had a significantly higher rate of spontaneous delivery within 2 weeks and 4 weeks of an amniocentesis [40.7% (11/27) versus 5.4% (2/37); 63.0% (17/27) versus 24.3% (9/37)] and a shorter interval-to-delivery period than those with a negative test [interval-to-delivery: median (range), 16 d (0-95 d) versus 42 d (2-91 d); p < 0.05 for each].

CONCLUSION

We conclude that 42% of patients with an early spontaneous preterm delivery (< 30 weeks) could be identified by a rapid MMP-8 bedside test at the time of their mid-trimester genetic amniocentesis. The MMP-8 bedside test is a powerful predictor of early spontaneous preterm birth in asymptomatic pregnant women.

Gastric fluid versus amniotic fluid analysis for the identification of intra-amniotic infection due to Ureaplasma species

OBJECTIVE

Early neonatal sepsis is often due to intra-amniotic infection. The stomach of the neonate contains fluid swallowed before and during delivery. The presence of bacteria as well as neutrophils detected by culture or Gram stain of the gastric fluid during the first day of life is suggestive of exposure to bacteria or inflammation. We undertook this study to determine the relationship between gastric fluid analysis and amniotic fluid obtained by transabdominal amniocentesis in the detection of Ureaplasma species, the most frequent microorganisms responsible for intra-amniotic infection.

MATERIALS AND METHODS

The study population consisted of 100 singleton pregnant women who delivered preterm neonates (<35 weeks) within 7 days of amniocentesis. Gastric fluid of newborns was obtained by nasogastric intubation on the day of birth. Amniotic fluid and gastric fluid were cultured for genital Mycoplasmas, and polymerase chain reaction (PCR) for Ureaplasma species was performed. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL).

RESULTS

(1) Ureaplasma species were detected by culture or PCR in 18% (18/100) of amniotic fluid samples and in 5% (5/100) of gastric fluid samples; (2) among the amniotic fluid cases positive for Ureaplasma species, these microorganisms were identified in 27.8% (5/18) of gastric fluid samples; (3) none of the cases negative for Ureaplasma species in the amniotic fluid were found to be positive for these microorganisms in the gastric fluid; (4) patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms had a significantly higher rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death than those with both amniotic fluid and gastric fluid negative for Ureaplasma species; and (5) no significant differences were observed in the rate of intra-amniotic inflammation, acute histologic chorioamnionitis, and neonatal death between patients with amniotic fluid positive for Ureaplasma species but with gastric fluid negative for these microorganisms and those with both amniotic fluid and gastric fluid positive for Ureaplasma species.

CONCLUSIONS

Gastric fluid analysis has 100% specificity in the identification of intra-amniotic infection with Ureaplasma species. However, the detection of Ureaplasma species by culture or PCR in the gastric fluid of neonates at birth did not identify these microorganisms in two-thirds of cases with microbial invasion of the amniotic cavity. Thus, amniotic fluid analysis is superior to that of gastric fluid in the identification of intra-amniotic infection.

Evidence of perturbations of the cytokine network in preterm labor

OBJECTIVE

Intraamniotic inflammation/infection is the only mechanism of disease with persuasive evidence of causality for spontaneous preterm labor/delivery. Previous studies about the behavior of cytokines in preterm labor have been largely based on the analysis of the behavior of each protein independently. Emerging evidence indicates that the study of biologic networks can provide insight into the pathobiology of disease and improve biomarker discovery. The goal of this study was to characterize the inflammatory-related protein network in the amniotic fluid of patients with preterm labor.

STUDY DESIGN

A retrospective cohort study was conducted that included women with singleton pregnancies who had spontaneous preterm labor and intact membranes (n = 135). These patients were classified according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry, and amniotic fluid concentration of interleukin (IL)-6 into the following groups: (1) those without intraamniotic inflammation (n = 85), (2) those with microbial-associated intraamniotic inflammation (n = 15), and (3) those with intraamniotic inflammation without detectable bacteria (n = 35). Amniotic fluid concentrations of 33 inflammatory-related proteins were determined with the use of a multiplex bead array assay.

RESULTS

Patients with preterm labor and intact membranes who had microbial-associated intraamniotic inflammation had a higher amniotic fluid inflammatory-related protein concentration correlation than those without intraamniotic inflammation (113 perturbed correlations). IL-1β, IL-6, macrophage inflammatory protein (MIP)-1α, and IL-1α were the most connected nodes (highest degree) in this differential correlation network (degrees of 20, 16, 12, and 12, respectively). Patients with sterile intraamniotic inflammation had correlation patterns of inflammatory-related proteins, both increased and decreased, when compared to those without intraamniotic inflammation (50 perturbed correlations). IL-1α, MIP-1α, and IL-1β were the most connected nodes in this differential correlation network (degrees of 12, 10, and 7, respectively). There were more coordinated inflammatory-related protein concentrations in the amniotic fluid of women with microbial-associated intraamniotic inflammation than in those with sterile intraamniotic inflammation (60 perturbed correlations), with IL-4 and IL-33 having the largest number of perturbed correlations (degrees of 15 and 13, respectively).

CONCLUSIONS

We report for the first time an analysis of the inflammatory-related protein network in spontaneous preterm labor. Patients with preterm labor and microbial-associated intraamniotic inflammation had more coordinated amniotic fluid inflammatory-related proteins than either those with sterile intraamniotic inflammation or those without intraamniotic inflammation. The correlations were also stronger in patients with sterile intraamniotic inflammation than in those without intraamniotic inflammation. The findings herein could be of value in the development of biomarkers of preterm labor.

A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10

OBJECTIVE

Intra-amniotic inflammation is a mechanism of disease implicated in preterm labor, preterm prelabor rupture of membrane, cervical insufficiency, a short cervix, and idiopathic vaginal bleeding. Determination of interleukin (IL)-6 with immunoassays has been proven for more than two decades to be an excellent method for the detection of intra-amniotic inflammation. However, assessment of IL-6 for this indication has been based on immunoassays which are not clinically available, and this has been an obstacle for the implementation of this test in clinical practice. It is now possible to obtain results within 20 min with a point of care (POC) test which requires minimal laboratory support. This test is based on lateral flow-based immunoassay. The objective of this study was to compare amniotic fluid (AF) IL-6 and interferon-γ - inducible protein 10 (IP-10 or CXCL-10) concentrations determined using lateral flow-based immunoassay or POC test and standard enzyme-linked immunosorbent assay (ELISA) techniques.

MATERIAL AND METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 20). AF IL-6 and IP-10 concentrations were determined by lateral flow-based immunoassay and ELISA. Intra-amniotic inflammation was defined as AF IL-6 ≥ 2.6 ng/ml. AF IL-6 and IP-10 concentrations between two assays were compared.

RESULTS

(1) Lateral flow-based immunoassay POC AF IL-6 and IP-10 test results were strongly correlated with concentrations of this cytokine/chemokine determined by ELISA (Spearman's ρ = 0.92 and 0.83, respectively, both p < 0.0001); (2) AF IL-6 concentrations determined by the lateral flow-based immunoassay test were, on average, 30% lower than those determined by ELISA, and the median difference was statistically significant (p < 0.0001); and (3) in contrast, AF IP-10 concentrations determined by the lateral flow-based immunoassay test were, on average, only 7% lower than those determined by ELISA, and the median difference was not statistically significant (p = 0.81).

CONCLUSION

AF IL-6 and IP-10 concentrations determined using a lateral flow-based immunoassay POC are strongly correlated with concentrations determined by conventional ELISA. This justifies further studies about the diagnostic indices and predictive values of this POC test.

A Case of Delayed Interval Delivery with a Successful Hospital Move

This report is the first case of delayed interval twin delivery in which the first infant and mother survived without major morbidity following transport to another facility. In addition, this case is only the second report of asynchronous delivery in which both twins survived and neither suffered any major morbidity. A 30-year-old G₅P₁₀₃₁ African American female with a diamniotic/dichorionic twin pregnancy presented to U.S. Naval Hospital Okinawa, Japan, at 22 + 5 weeks due to vaginal bleeding. At 23 + 2 weeks, Twin A was born secondary to advanced cervical dilation. Twin A's birth weight was 650 g with APGAR scores of 6 (1 min) and 7 (5 min). Following delivery of Twin A, Placenta A was left in utero with high ligation of the umbilical cord. Due to a scheduled hospital move, the mother and Twin A were transported to the new facility at Camp Foster. Three weeks later, Twin B was delivered at 26 + 4 weeks. Twin B's birth weight was 930 g with APGAR scores of 3 (1 min) and 7 (5 min). Both twins were discharged without IVH, PVL, ROP, or CLD. This case demonstrates the possibility of transporting both the mother and surviving infant A to a higher level of care prior to delivery of subsequent fetuses.

Inflammatory and Angiogenic Factors at Mid-Pregnancy Are Associated with Spontaneous Preterm Birth in a Cohort of Tanzanian Women

Research Question

Preterm birth (PTB) is the leading cause of perinatal mortality worldwide, with the greatest burden occurring in resource-constrained settings. Based on the hypothesis that altered placental angiogenesis and inflammation early in pregnancy lead to PTB, we examined whether levels of inflammatory and angiogenic mediators, measured early in pregnancy, were predictive of spontaneous PTB (sPTB).

Study Design

Plasma samples were collected from a prospective cohort of primigravid Tanzanian women between 12–27 weeks gestation. A panel of 18 markers was screened on a training cohort of 426 women. Markers associated with sPTB in the training cohort were repeated in a test cohort of 628 women. All markers were measured by ELISA.

Findings

In both the training and test cohorts plasma levels of IL-18BP, sICAM-1, sEndoglin and CHI3L1 were elevated and Leptin was lower at enrollment in women who subsequently experienced sPTB. In multivariate analysis women with plasma levels of CHI3L1, C5a, sICAM-1, AngptL3, sEndgolin, sFlt-1 and IL-18BP in the highest quartile had an increased risk of sPTB compared with those in the lowest quartile. Women with Leptin and Ang2 in the highest quartile had a reduced risk of sPTB compared with women in the lowest quartile.

Implications

Levels of angiogenic and inflammatory mediators measured at mid-pregnancy were associated with subsequent sPTB. These findings provide insight into mechanisms underlying sPTB and suggest biomarkers that may have clinical utility in risk-stratifying pregnancies.

Sterile intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix: prevalence and clinical significance

OBJECTIVE

To determine the frequency and clinical significance of sterile and microbial-associated intra-amniotic inflammation in asymptomatic patients with a sonographic short cervix.

METHODS

Amniotic fluid (AF) samples obtained by transabdominal amniocentesis from 231 asymptomatic women with a sonographic short cervix [cervical length (CL) ≤25 mm] were analyzed using cultivation techniques (for aerobic and anaerobic as well as genital mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). The frequency and magnitude of intra-amniotic inflammation [defined as an AF interleukin (IL)-6 concentration ≥2.6 ng/mL], acute histologic placental inflammation, spontaneous preterm delivery (sPTD), and the amniocentesis-to-delivery interval were examined according to the results of AF cultures, PCR/ESI-MS and AF IL-6 concentrations.

RESULTS

Ten percent (24/231) of patients with a sonographic short cervix had sterile intra-amniotic inflammation (an elevated AF IL-6 concentration without evidence of microorganisms using cultivation and molecular methods). Sterile intra-amniotic inflammation was significantly more frequent than microbial-associated intra-amniotic inflammation [10.4% (24/231) versus 2.2% (5/231); p < 0.001]. Patients with sterile intra-amniotic inflammation had a significantly higher rate of sPTD <34 weeks of gestation [70.8% (17/24) versus 31.6% (55/174); p < 0.001] and a significantly shorter amniocentesis-to-delivery interval than patients without intra-amniotic inflammation [median 35, (IQR: 10-70) versus median 71, (IQR: 47-98) days, (p < 0.0001)].

CONCLUSION

Sterile intra-amniotic inflammation is more common than microbial-associated intra-amniotic inflammation in asymptomatic women with a sonographic short cervix, and is associated with increased risk of sPTD (<34 weeks). Further investigation is required to determine the causes of sterile intra-amniotic inflammation and the mechanisms whereby this condition is associated with a short cervix and sPTD.

DNA methylation provides insight into intergenerational risk for preterm birth in African Americans

African Americans are at increased risk for spontaneous preterm birth (PTB). Though PTB is heritable, genetic studies have not identified variants that account for its intergenerational risk, prompting the hypothesis that epigenetic factors may also contribute. The objective of this study was to evaluate DNA methylation from maternal leukocytes to identify patterns specific to PTB and its intergenerational risk. DNA from peripheral leukocytes from African American women that delivered preterm (24-34 weeks; N = 16) or at term (39-41 weeks; N = 24) was assessed for DNA methylation using the HumanMethylation450 BeadChip. In maternal samples, 17,829 CpG sites associated with PTB, but no CpG site remained associated after correction for multiple comparisons. Examination of paired maternal-fetal samples identified 5,171 CpG sites in which methylation of maternal samples correlated with methylation of her respective fetus (FDR < 0.05). These correlated sites were enriched for association with PTB in maternal leukocytes. The majority of correlated CpG sites could be attributed to one or more genetic variants. They were also significantly more likely to be in genes involved in metabolic, cardiovascular, and immune pathways, suggesting a role for genetic and environmental contributions to PTB risk and chronic disease. The results of this study may provide insight into the factors underlying intergenerational risk for PTB and its consequences.

[Preterm rupture of membranes: Is home care a safe management?]

OBJECTIVE

Compare the maternal and neonatal outcomes in pregnancies complicated by preterm prelabour rupture of membranes (PPROM), which were managed either at home (HAD) or hospital (HC).

MATERIALS AND METHODS

Retrospective study in two level III maternities during 2 years. Inclusion criteria in HAD were: singleton pregnancy, PPROM between 24 and 35 weeks of gestation, absence of chorioamnionitis, clinical stability at D7 of the rupture, cervical dilatation <3 cm, patient residing in the geographic area.

RESULTS

Thirty-two patients were included in the HAD group and 24 in the HC group. Our populations were similar in the 2 groups. The duration of latency was longer in the HAD group than in the HC group (27.5 d [20-37] versus 16.5 d [12.5 to 29.5]; P=0.026). Patients in the HAD group received fewer antibiotics with a similar rate of chorioamnionitis. No difference in terms of obstetrical and neonatal outcomes was observed. Number of days in neonatal resuscitation was lower in the HAD group than in the HC group (12.5 d [10-22] versus 43 d [20-52]; P=0.003).

CONCLUSION

HAD seems to be an alternative to continuous hospitalization for patients followed for PPROM between 24 and 35 weeks. A randomized study with a larger number of patients, including other data such as maternal satisfaction and cost analysis, would be interesting to confirm those preliminary results.

Viral infections during pregnancy

Viral infections during pregnancy have long been considered benign conditions with a few notable exceptions, such as herpes virus. The recent Ebola outbreak and other viral epidemics and pandemics show how pregnant women suffer worse outcomes (such as preterm labor and adverse fetal outcomes) than the general population and non-pregnant women. New knowledge about the ways the maternal-fetal interface and placenta interact with the maternal immune system may explain these findings. Once thought to be 'immunosuppressed', the pregnant woman actually undergoes an immunological transformation, where the immune system is necessary to promote and support the pregnancy and growing fetus. When this protection is breached, as in a viral infection, this security is weakened and infection with other microorganisms can then propagate and lead to outcomes, such as preterm labor. In this manuscript, we review the major viral infections relevant to pregnancy and offer potential mechanisms for the associated adverse pregnancy outcomes.

Obstetric and neonatal outcomes after preterm premature rupture of membranes among women carrying group B streptococcus

OBJECTIVE

To evaluate whether carriers of group B streptococcus (GBS) have adverse obstetric and neonatal outcomes when preterm premature rupture of membranes (PPROM) occurs.

METHODS

In a retrospective study, data were reviewed for women with a singleton pregnancy and PPROM before 34 weeks who attended the Meir Medical Center, Kfar Saba, Israel, between 2005 and 2012. All women received roxithromycin for 1 week, and ampicillin until GBS culture results were available. Ampicillin was continued to 1 week if the GBS culture was positive. The primary study outcome measure was the latency period (time from rupture of membranes to active/induced labor).

RESULTS

Among 116 eligible patients, 21 (18.1%) were GBS carriers and 95 (81.9%) noncarriers. The latency period was 11.2 ± 18.1 days for GBS carriers versus 7.5 ± 9.6 days for noncarriers (P=0.93). However, there was a correlation between the length of ampicillin treatment and the latency period (Spearman correlation coefficient 0.7; P<0.001). There were no differences in early neonatal outcomes.

CONCLUSION

GBS carriers with PPROM did not have adverse outcomes. Longer treatment with ampicillin among GBS carriers prolonged the latency period.

Effect of intensive oral hygiene regimen during pregnancy on periodontal health, cytokine levels, and pregnancy outcomes: a pilot study

BACKGROUND

Data are limited on the potential effect of intensive oral hygiene regimens and periodontal therapy during pregnancy on periodontal health, gingival crevicular fluid (GCF) and serum cytokines, and pregnancy outcomes.

METHODS

A clinical trial was conducted on 120 community-dwelling, 16- to 35-year-old pregnant women at 16 to 24 weeks of gestation. Each participant presented with clinical evidence of generalized, moderate-to-severe gingivitis. Oral hygiene products were provided, together with instructions for an intensive daily regimen of hygiene practices. Non-surgical therapy was provided at baseline. Oral examinations were completed at baseline and again at 4 and 8 weeks. In addition, samples of blood and GCF were collected at baseline and week 8. Mean changes in clinical variables and GCF and serum cytokine levels (interleukin [IL]-1β, IL-6, tumor necrosis factor [TNF]-α) between baseline and week 8 were calculated using paired t test. Pregnancy outcomes were recorded at parturition.

RESULTS

RESULTS indicated a statistically significant reduction in all clinical variables (P <0.0001) and decreased levels of TNF-α (P = 0.0076) and IL-1β (P = 0.0098) in GCF during the study period. The rate of preterm births (<37 weeks of gestation) was 6.7% (P = 0.113) and low birth weight (<2,500 g) was 10.2% (P = 1.00).

CONCLUSIONS

Among the population studied, intensive instructions and non-surgical periodontal therapy provided during 8 weeks at early pregnancy resulted in decreased gingival inflammation and a generalized improvement in periodontal health. Large-scale, randomized, controlled studies are needed to substantiate these findings.