Differences in inflammatory markers between nulliparous women admitted to hospitals in preactive vs active labor

Characterizing uterine responsiveness to oxytocin augmentation across four labor patterns in maternal obesity

BACKGROUND

Optimizing care during labor protraction is a key strategy for reducing cesareans, especially among people with obesity. The pathophysiology of labor dystocia remains poorly understood, limiting precise interventions targeting the cause of protraction.

METHODS

In this secondary analysis of nulliparas (n = 92) with obesity (BMI ≥ 30 kg/m2) and spontaneous labor onset, we classified labor into four phenotypes based on duration of protraction and birth route: (1) no protraction, (2) short protraction and vaginal birth, (3) extended protraction meeting criteria for labor arrest, but with eventual progression and vaginal birth, and (4) extended protraction meeting criteria for labor arrest and cesarean birth. Across these phenotypes, we compared MVU, oxytocin dose, and novel measures of uterine responsiveness to oxytocin augmentation (MVU to oxytocin dose ratios).

RESULTS

In our sample, phenotype group 1 comprised 14.1% (n = 13); group 2 comprised 30.4% (n = 28); group 3 comprised 34.8% (n = 32); and group 4 comprised 20.7% (n = 19). Uterine responsiveness to oxytocin, but not MVU, decreased with each labor phenotype. Participants with cesarean birth had the lowest uterine responsiveness to oxytocin.

CONCLUSION

Labor and birth outcomes were associated with measures of uterine responsiveness to oxytocin rather than MVU alone, and thus these may be more clinically appropriate measures for guiding clinical decision-making. Current criteria for labor arrest are likely too stringent for nulliparas with obesity, many of whom appear to progress to safe vaginal birth after longer labor durations. Differences in uterine responsiveness to oxytocin augmentation across the groups suggests underlying physiologic differences in the labor phenotypes, which should drive future research targeting pathophysiology.

Fever in childbirth: a mini-review of epidural-related maternal fever

Fever during childbirth, which is often observed in clinical settings, is characterized by a temperature of 38°C or higher, and can occur due to infectious and non-infectious causes. A significant proportion of non-infectious causes are associated with epidural-related maternal fever during vaginal delivery. Therapeutic interventions are required because fever has adverse effects on both mother and newborn. Effective treatment options for ERMF are lacking. As it is difficult to distinguish it from intrauterine infections such as chorioamnionitis, antibiotic administration remains the only viable option. We mentioned the importance of interleukin-1 receptor antagonist in the sterile inflammatory fever pathway and the hormonal influence on temperature regulation during childbirth, an important factor in elucidating the pathophysiology of ERMF. This review spotlighted the etiology and management of ERMF, underscoring recent advancements in our understanding of hypothalamic involvement in thermoregulation and its link to sterile inflammation. We propose to deepen the understanding of ERMF within the broader context of autonomic neuroscience, aiming to foster the development of targeted therapies.

Clinical chorioamnionitis at term is characterized by changes in the plasma concentration of CHCHD2/MNRR1, a mitochondrial protein

OBJECTIVE

Mitochondrial dysfunction was observed in acute systemic inflammatory conditions such as sepsis and might be involved in sepsis-induced multi-organ failure. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2), also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1), a bi-organellar protein located in the mitochondria and the nucleus, is implicated in cell respiration, survival, and response to tissue hypoxia. Recently, the reduction of the cellular CHCHD2/MNRR1 protein, as part of mitochondrial dysfunction, has been shown to play a role in the amplification of inflammatory cytokines in a murine model of lipopolysaccharide-induced systemic inflammation. The aim of this study was to determine whether the plasma concentration of CHCHD2/MNRR1 changed during human normal pregnancy, spontaneous labor at term, and clinical chorioamnionitis at term.

METHODS

We conducted a cross-sectional study that included the following groups: 1) non-pregnant women (n = 17); 2) normal pregnant women at various gestational ages from the first trimester until term (n = 110); 3) women at term with spontaneous labor (n = 50); and 4) women with clinical chorioamnionitis at term in labor (n = 25). Plasma concentrations of CHCHD2/MNRR1 were assessed by an enzyme-linked immunosorbent assay.

RESULTS

1) Pregnant women at term in labor with clinical chorioamnionitis had a significantly higher plasma CHCHD2/MNRR1 concentration than those in labor without chorioamnionitis (p = .003); 2) CHCHD2/MNRR1 is present in the plasma of healthy non-pregnant and normal pregnant women without significant differences in its plasma concentrations between the two groups; 3) there was no correlation between maternal plasma CHCHD2/MNRR1 concentration and gestational age at venipuncture; and 4) plasma CHCHD2/MNRR1 concentration was not significantly different in women at term in spontaneous labor compared to those not in labor.

CONCLUSIONS

CHCHD2/MNRR1 is physiologically present in the plasma of healthy non-pregnant and normal pregnant women, and its concentration does not change with gestational age and parturition at term. However, plasma CHCHD2/MNRR1 is elevated in women at term with clinical chorioamnionitis. CHCHD2/MNRR1, a novel bi-organellar protein located in the mitochondria and the nucleus, is released into maternal plasma during systemic inflammation.

New insights on labor progression: a systematic review

The past 20 years witnessed an invigoration of research on labor progression and a change of thinking regarding normal labor. New evidence is emerging, and more advanced statistical methods are applied to labor progression analyses. Given the wide variations in the onset of active labor and the pattern of labor progression, there is an emerging consensus that the definition of abnormal labor may not be related to an idealized or average labor curve. Alternative approaches to guide labor management have been proposed; for example, using an upper limit of a distribution of labor duration to define abnormally slow labor. Nonetheless, the methods of labor assessment are still primitive and subject to error; more objective measures and more advanced instruments are needed to identify the onset of active labor, monitor labor progression, and define when labor duration is associated with maternal/child risk. Cervical dilation alone may be insufficient to define active labor, and incorporating more physical and biochemical measures may improve accuracy of diagnosing active labor onset and progression. Because the association between duration of labor and perinatal outcomes is rather complex and influenced by various underlying and iatrogenic conditions, future research must carefully explore how to integrate statistical cut-points with clinical outcomes to reach a practical definition of labor abnormalities. Finally, research regarding the complex labor process may benefit from new approaches, such as machine learning technologies and artificial intelligence to improve the predictability of successful vaginal delivery with normal perinatal outcomes.

Epidural-related maternal fever: incidence, pathophysiology, outcomes, and management

Epidural-related maternal fever affects 15% to 25% of patients who receive a labor epidural. Two meta-analyses demonstrated that epidural-related maternal fever is a clinical phenomenon, which is unlikely to be caused by selection bias. All commonly used neuraxial techniques, local anesthetics with or without opioids, and maintenance regimens are associated with epidural-related maternal fever, however, the impact of each component is unknown. Two major theories surrounding epidural-related maternal fever development have been proposed. First, labor epidural analgesia may lead to the development of hyperthermia through a sterile (noninfectious) inflammatory process. This process may involve reduced activation of caspase-1 (a protease involved in cell apoptosis and activation of proinflammatory pathways) secondary to bupivacaine, which impairs the release of the antipyrogenic cytokine, interleukin-1-receptor antagonist, from circulating leucocytes. Detailed mechanistic processes of epidural-related maternal fever remain to be determined. Second, thermoregulatory mechanisms secondary to neuraxial blockade have been proposed, which may also contribute to epidural-related maternal fever development. Currently, there is no prophylactic strategy that can safely prevent epidural-related maternal fever from occurring nor can it easily be distinguished clinically from other causes of intrapartum fever, such as chorioamnionitis. Because intrapartum fever (of any etiology) is associated with adverse outcomes for both the mother and baby, it is important that all parturients who develop intrapartum fever are investigated and treated appropriately, irrespective of labor epidural utilization. Institution of treatment with appropriate antimicrobial therapy is recommended if an infectious cause of fever is suspected. There is currently insufficient evidence to warrant a change in recommendations regarding provision of labor epidural analgesia and the benefits of good quality labor analgesia must continue to be reiterated to expectant mothers.

Is human labor at term an inflammatory condition?†

Parturition at term in normal pregnancy follows a predictable sequence of events. There is some evidence that a state of inflammation prevails in the reproductive tissues during labor at term, but it is uncertain whether this phenomenon is the initiating signal for parturition. The absence of a clear temporal sequence of inflammatory events prior to labor casts doubt on the concept that normal human labor at term is primarily the result of an inflammatory cascade. This review examines evidence linking parturition and inflammation in order to address whether inflammation is a cause of labor, a consequence of labor, or a separate but related phenomenon. Finally, we identify and suggest ways to reconcile inconsistencies regarding definitions of labor onset in published research, which may contribute to the variability in conclusions regarding the genesis and maintenance of parturition. A more thorough understanding of the processes underlying normal parturition at term may lead to novel insights regarding abnormal labor, including spontaneous preterm labor, preterm premature rupture of the fetal membranes, and dysfunctional labor, and the role of inflammation in each.

Dynamic changes in maternal immune biomarkers during labor in nulliparous vs multiparous women

BACKGROUND

Immunomodulation is observed in human parturition. However, data from longitudinal studies for the prelabor phase and the active phase of labor are lacking, and no study had compared the immune responses during labor between nulliparous and multiparous women.

OBJECTIVE

This study aimed to investigate the temporal changes of immune biomarkers in maternal blood from the prelabor phase to the latent and active phases of labor and to compare the dynamic changes between nulliparous and multiparous women.

STUDY DESIGN

A prospective case-control study was conducted on women who had induction of labor at term followed by vaginal delivery. Maternal blood was serially collected at 3 consecutive time points: (1) before the onset of labor, (2) during the latent phase of labor, and (3) during the active phase of labor. Peripheral immune cells were measured by 4-color flow cytometry, and the plasma concentrations of cytokines and chemokines were measured by cytometric bead arrays. A longitudinal comparison was made to assess the dynamic changes in inflammatory parameters over 3 time points in nulliparous and multiparous women, respectively, and a cross-sectional comparison was made between nulliparous and multiparous women.

RESULTS

A total of 40 women, including 20 nulliparous and 20 multiparous, were included in the study. Prelabor circulating levels of macrophage inflammatory protein-1β, monokine induced by gamma interferon, and interferon gamma-induced protein-10 were higher in multiparous women than in nulliparous women. In the latent phase of labor, the innate immune system in both groups responded with increases in neutrophils and interleukin 6, and the nulliparous women showed a more pronounced response. During the active phase of labor, such innate immune response continued with both groups, with additional increases in natural killer cells, monocyte chemoattractant protein-1, interleukin 8, and interleukin 10. Conversely, the adaptive immune system in nulliparous women showed a reduction in both cytotoxic and helper T cells, whereas the adaptive immune system in multiparous women only had a reduction in helper T cells, showing a smaller reduction.

CONCLUSION

Innate and adaptive immune responses partake in immunomodulation during human parturition. Nulliparous and multiparous women showed different responses in their blood levels of immune cells and biomarkers during the different phases of labor.

Transcriptome changes in maternal peripheral blood during term parturition mimic perturbations preceding spontaneous Preterm birth†

The complex physiologic process of parturition includes the onset of labor, which requires the orchestrated stimulation of a common pathway involving uterine contractility, cervical ripening, and chorioamniotic membrane activation. However, the labor-specific processes taking place in these tissues have limited use as predictive biomarkers unless they can be probed in non-invasive samples, such as the peripheral blood. Herein, we utilized a transcriptomic dataset to assess labor-specific changes in the peripheral blood of women who delivered at term. We identified a set of genes that were differentially expressed with labor and enriched for immunological processes, and these gene expression changes were strongly correlated with results from prior studies, providing in silico validation of our findings. We then identified significant correlations between labor-specific transcriptomic changes in the maternal circulation and those reported in the chorioamniotic membranes, myometrium, and cervix of women at term, demonstrating that tissue-specific labor signatures are partly mirrored in the peripheral blood. Last, we demonstrated a significant overlap between the peripheral blood transcriptomic changes in term parturition and those observed in asymptomatic women prior to the diagnosis of preterm prelabor rupture of membranes who delivered preterm. Collectively, we provide evidence that the normal process of labor at term is characterized by a unique immunological expression signature, which may serve as a useful tool for assessing labor status and potentially identifying women at risk for preterm birth.

Decidual Inflammation Drives Chemokine-Mediated Immune Infiltration Contributing to Term Labor

Infiltration of maternal peripheral leukocytes into the uterine tissues is a critical event occurring before, during, and after term labor (TL). In this article, we investigate the contribution of uterine smooth muscle (myometrium) and pregnant endometrium (decidua) to the inflammatory process during human TL. We hypothesize that labor-related physiological inflammation is orchestrated by uterine-secreted cytokines, which dually activate the uterine vascular endothelium and maternal leukocytes to promote their adhesion and infiltration into the uterus. Using Luminex and ELISA assays, we examine a full range of cytokines (45 proteins) in media conditioned by primary decidual and myometrial cells from TL and term not in labor (TNL) women. The effect of conditioned media on the activation of human uterine microvascular endothelial cells was measured by qPCR and on peripheral leukocytes by flow cytometry. Transendothelial migration of calcein-labeled primary leukocytes toward media was assessed by fluorometry. Stromal decidual cells secrete significantly higher levels of multiple cytokines compared with myometrial cells (p < 0.05) and significantly more cytokines during TL than TNL. These cytokines activate uterine microvascular endothelial cells through the upregulation of cell adhesion molecule VCAM-1 and peripheral leukocytes by upregulation of CD11b. Furthermore, multiple cytokines secreted from the TL decidua and myometrium significantly increase migration of granulocytes, monocytes, and lymphocytes compared with TNL (p < 0.05), which was blocked by a broad-spectrum chemokine inhibitor (FX125L). These data reveal the critical role for decidual- and myometrial-secreted cytokines in the activation of inflammatory pathways leading to labor. We suggest that these pathways represent targets for therapeutic intervention during preterm labor.

Serum markers of B-cell activation in pregnant women with atopic asthma

PROBLEM

As maternal atopy represents a risk factor for the development of atopy in offspring, we aimed to assess how pregnancy affects B-cell activation markers in women with atopic asthma and whether they correlate with risk manifestations for allergy in newborns from mothers with atopic asthma.

METHOD OF STUDY

Pregnant women with atopic asthma (AP) in the third trimester of gestation and nonpregnant women with atopic asthma (ANP) were prospectively recruited and compared to respective healthy counterparts (HP and HNP). All pregnant women were also assessed during the postpartum period until 6 weeks after delivery (HP/PP and AP/PP). Newborns were clinically evaluated at the age of 6 months. Peripheral blood samples were taken from each woman at each time point. Soluble CD23 (sCD23), B-cell activating factor (BAFF), IgA, IgG, IgM, kappa (κ), and lambda (λ) free light chains (FLC) were quantified in serum samples.

RESULTS

The AP group presented increased sCD23 (p < 0.05) and BAFF (p < 0.001) levels compared to the ANP group and even higher levels of sCD23 during the postpartum period (p < 0.001). Moreover, the cutoffs of 6.74 g/L for IgG (sensitivity 90.9%, specificity 77.8%) and of 11.30 mg/L for λ FLC (sensitivity 81.8%, specificity 88.9%) in the AP group were predictive factors for the manifestation of allergy in their offspring.

CONCLUSIONS

After delivery, the dynamics of sCD23 and BAFF changed significantly in the AP group. Furthermore, we found novel predictive factors for allergy manifestations in the children of these women, with potential clinical application.

Association of lymphocyte count and incidence of maternal fever in epidural analgesia-involved labor

Background

Evidence showed that the use of epidural analgesia increased the risk of maternal fever during labor, and the potential mechanisms involved inflammation. Lymphocyte played a role in the inflammatory responses, and lymphopenia predicted adverse outcomes for patients. The aim of this study was to investigate whether lymphocyte count was associated with the incidence of intrapartum fever in nulliparous women undergoing vaginal delivery.

Methods

In this retrospective cohort study, electronic medical record data at the International Peace Maternity and Child Health Hospital (IPMCH, Shanghai, China) between 2012 and 2017 were extracted. The primary outcome of this study was baseline lymphocyte count in febrile and afebrile parturients who received labor epidural analgesia. Other confounding factors associated with the development of intrapartum fever were analyzed using multivariable logistic regression.

Results

The final study population consisted of 36,562 parturients, of whom 18,952 (51.8%) received labor epidural analgesia. Labor epidural analgesia was associated with an increased risk of maternal fever [relative risk: 4.55; 95% confidence interval (CI): 4.16–4.98; P<0.001]. Among the parturients who received epidural analgesia, both baseline lymphocyte count and lymphocyte percentage were lower in the febrile patients than those in the afebrile patients (P<0.001; P=0.015). The lower (<1.1×10⁹/L) baseline lymphocyte was associated with a higher risk of maternal fever (adjusted odds ratio: 1.30, 95% CI: 1.14–1.48; P<0.001).

Conclusions

Our results suggested that lower lymphocyte baseline indicated an increased risk of maternal fever during epidural analgesia-involved labor. Further studies are needed to confirm the findings and determine the potential mechanisms.

Ageing in human parturition: impetus of the gestation clock in the decidua†

Despite sharing many common features, the relationship between ageing and parturition remains poorly understood. The decidua is a specialized lining of endometrial tissue, which develops in preparation for pregnancy. The structure and location of the decidua support its role as the physical scaffold for the growing embryo and placenta, and thus, it is vital to sustain pregnancy. Approaching term, the physical support properties of the decidua are naturally weakened to permit parturition. In this review, we hypothesize that the natural weakening of decidual tissue at parturition is promoted by the ageing process. Studies of the ageing-related functional and molecular changes in the decidua at parturition are reviewed and classified using hallmarks of ageing as the framework. The potential roles of decidual mesenchymal stem/stromal cell (DMSC) ageing in labor are also discussed because, although stem cell exhaustion is also a hallmark of ageing, its role in labor is not completely understood. In addition, the potential roles of extracellular vesicles secreted by DMSCs in labor, and their parturition-related miRNAs, are reviewed to gain further insight into this research area. In summary, the literature supports the notion that the decidua ages as the pregnancy progresses, and this may facilitate parturition, suggesting that ageing is the probable impetus of the gestational clocks in the decidua. This conceptual framework was developed to provide a better understanding of the natural ageing process of the decidua during parturition as well as to encourage future studies of the importance of healthy ageing for optimal pregnancy outcomes.

The effects of advanced maternal age on T-cell subsets at the maternal-fetal interface prior to term labor and in the offspring: a mouse study

Women who conceive at 35 years of age or older, commonly known as advanced maternal age, have a higher risk of facing parturition complications and their children have an increased risk of developing diseases later in life. However, the immunological mechanisms underlying these pathological processes have yet to be established. To fill this gap in knowledge, using a murine model and immunophenotyping, we determined the effect of advanced maternal age on the main cellular branch of adaptive immunity, T cells, at the maternal-fetal interface and in the offspring. We report that advanced maternal age impaired the process of labor at term, inducing dystocia and delaying the timing of delivery. Advanced maternal age diminished the number of specific proinflammatory T-cell subsets [T helper type 1 (Th1): CD4⁺ IFN-γ⁺ , CD8⁺ IFN-γ⁺ and Th9: CD4⁺ IL-9⁺ ], as well as CD4⁺ regulatory T cells (CD4⁺ CD25⁺ FoxP3⁺ T cells), at the maternal-fetal interface prior to term labor. Advanced maternal age also altered fetal growth and survival of the offspring in early life. In addition, infants born to advanced-age mothers had alterations in the T-cell repertoire but not in CD71⁺ erythroid cells (CD3^- CD71⁺ TER119⁺ cells). This study provides insight into the immune alterations observed at the maternal-fetal interface of advanced-age mothers and their offspring.

Epidural Fever: Hiding in the Shadows

Recent research has focused on inflammation and oxidative stress that is seen in women developing intrapartum fever. The interleukin-6 (IL-6) levels have been found to be elevated in women who receive epidural analgesia and become febrile. This suggests that the epidural itself induces an inflammatory response and it is not a physiologic process of labour. Similar findings with additional proinflammatory mediators and reactive oxygen species seem to support this theory. Epidural analgesia also affects the body’s thermoregulatory mechanisms. It causes an increase in shivering and appears to be associated with a decrease in heat dissipation via sweating and hyperventilation, most likely because of blockade of the sympathetic stimulation. Considering these factors, it is probable that epidurals do contribute to the development of the associated fever. There remains the possibility that subclinical chorioamnionitis might be the underlying cause of a subset of maternal intrapartum fevers. In summary, histologic chorioamnionitis and epidural analgesia appear to be the independent contributors to intrapartum fever.

Cell-Free Fetal DNA Increases Prior to Labor at Term and in a Subset of Preterm Births

Cell-free fetal DNA in the maternal circulation has been associated with the onset of labor at term. Moreover, clinical studies have suggested that cell-free fetal DNA has value to predict pregnancy complications such as spontaneous preterm labor leading to preterm birth. However, a mechanistic link between cell-free fetal DNA and preterm labor and birth has not been established. Herein, using an allogeneic mouse model in which a paternal green fluorescent protein (GFP) can be tracked in the fetuses, we established that cell-free fetal DNA (Egfp) concentrations were higher in late gestation compared to mid-pregnancy and were maintained at increased levels during the onset of labor at term, followed by a rapid decrease after birth. A positive correlation between cell-free fetal DNA concentrations and the number of GFP-positive pups was also observed. The increase in cell-free fetal DNA concentrations prior to labor at term was not linked to a surge in any specific cytokine/chemokine; yet, specific chemokines (i.e., CCL2, CCL7, and CXCL2) increased as gestation progressed and maintained elevated levels in the postpartum period. In addition, cell-free fetal DNA concentrations increased prior to systemic inflammation-induced preterm birth, which was associated with a strong cytokine response in the maternal circulation. However, cell-free fetal DNA concentrations were not increased prior to intra-amniotic inflammation-induced preterm birth, but in this model, a mild inflammatory response was observed in the maternal circulation. Collectively, these findings suggest that an elevation in cell-free fetal DNA concentrations in the maternal circulation precedes the physiological process of labor at term and the pathological process of preterm labor linked with systemic inflammation, but not that associated with intra-amniotic inflammation.

Systemic inflammation is associated with malaria and preterm birth in women living with HIV on antiretrovirals and co-trimoxazole

Women living with HIV (WLHIV) have an increased risk of malaria in pregnancy (MiP). It is unclear if MiP in WLHIV causes a systemic inflammatory response and increases the risk of adverse birth outcomes, especially for women receiving antiretroviral therapy (ART) and daily trimethoprim-sulfamethoxazole (TMP/SXT). We analyzed repeated plasma samples in a cohort of malaria-exposed Ugandan WLHIV receiving ART and daily TMP/SXT to examine changes in inflammatory markers across pregnancy and their association with birth outcomes. Concentrations of CHI3L1, CRP, IL-18BP, IL-6, sICAM-1, and sTNFR2 were quantified by ELISA in 1115 plasma samples collected over pregnancy from 326 women. MiP was associated with increased sTNFR2, sICAM-1 and IL-18BP concentrations across pregnancy. Women who delivered preterm had elevated concentrations of sTNFR2 and altered levels of IL-6 during pregnancy. Women with sTNFR2 concentrations in the highest quartile within 6 weeks of delivery had an increased relative risk of preterm birth. Our results indicate that despite daily TMP/SXT, MiP in WLHIV induced a systemic inflammatory response that was associated with an increased risk of preterm birth. These findings highlight the need for additional strategies to protect WLHIV from malaria infection in pregnancy to promote healthy outcomes for mother and child.

Applying a physiologic partograph to Consortium on Safe Labor data to identify opportunities for safely decreasing cesarean births among nulliparous women

BACKGROUND

The timing of hospital admission for women with spontaneous labor onset and the criteria used to assess active labor progress and diagnose labor dystocia may significantly influence women's risk for primary cesarean birth. Our aims were to assess associations of labor status at admission (i.e., preactive or active) and active labor progress (i.e., dystocic or physiologic) with oxytocin augmentation, cesarean birth, and adverse neonatal outcome rates.

METHODS

A sample of low-risk, nulliparous women admitted to hospitals for spontaneous labor onset was extracted from the Consortium on Safe Labor (n = 27 077). Binomial logistic regression was used to assess associations between labor classifications and outcomes.

RESULTS

At admission, 68.0% of women were in preactive labor and 32.0% were in active labor. Cesarean rates for these groups were 18.0% and 7.2%, respectively (adjusted odds ratio [AOR] 2.69; 95% CI 2.45-2.96). Oxytocin augmentation and adverse neonatal outcomes were more likely for women admitted in preactive labor. Among women admitted in active labor, 9.3% experienced labor dystocia and 90.7% progressed physiologically. Cesarean rates for these groups were 20.4% and 5.9%, respectively (AOR 3.02; 95% CI 2.45-3.73). Nearly half of the cesareans performed for dystocia among women admitted in active labor occurred when cervical dilation was physiologic. Oxytocin augmentation and adverse neonatal outcomes were more likely when active labor was dystocic.

CONCLUSIONS

Adoption of evidence-based, standardized approaches for diagnosing active labor onset, assessing labor progress, and diagnosing dystocia may safely decrease oxytocin augmentation and cesarean birth rates in the United States.

Likelihood of cesarean birth among parous women after applying leading active labor diagnostic guidelines

OBJECTIVES

Hospital admission during early labor may increase women's risk for medical and surgical interventions. However, it is unclear which diagnostic guideline is best suited for identifying the active phase of labor among parous women. Dr. Emanuel Friedman, the United Kingdom's National Institute for Health and Care Excellence (NICE), and the American College of Obstetricians and Gynecologists/Society for Maternal-Fetal Medicine (ACOG/SMFM) support different active labor diagnostic guidelines. Our aims were (1) to determine the proportions of parous women admitted to the hospital before or in active labor per these leading guidelines and (2) to compare associations of labor status at admission (i.e., early labor or active labor) with oxytocin augmentation, cesarean birth, and adverse birth outcomes when using the different active labor diagnostic guidelines.

DESIGN

Active labor diagnostic guidelines were applied retrospectively to cervical examination data. Binomial logistic regression was used to assess associations of labor status at admission (i.e., early labor relative to active labor) and outcomes.

SETTING

A large, academic, tertiary medical center in the Midwestern United States.

PARTICIPANTS

Parous women with spontaneous labor onset who gave birth to a single, cephalic-presenting fetus at term gestation between 2006 and 2010 (n = 3,219).

FINDINGS

At admission, 28.8%, 71.9%, and 24.4% of parous women were in active labor per Friedman, NICE, and ACOG/SMFM diagnostic guidelines, respectively. Oxytocin augmentation was more likely among women admitted in early labor, regardless of the diagnostic strategy used (p < 0.001 for each guideline). Cesarean birth was also more likely among women admitted before versus in active labor according to all guidelines (Friedman: adjusted odds ratio [AOR] 3.63 [95% CI 1.46-9.03]), NICE: AOR 2.71 [95% CI 1.47-4.99]), and ACOG/SMFM: AOR 2.11 [95% CI 1.02-4.34]). There were no differences in a composite measure of adverse outcomes within active labor diagnostic guidelines after adjusting for covariates.

KEY CONCLUSIONS

Many parous women with spontaneous labor onset are admitted to the hospital before active labor. These women are more likely to receive oxytocin augmentation during labor and are more likely to have a cesarean birth.

IMPLICATIONS FOR PRACTICE

Diagnosing active labor prior to admission or prior to intervention aimed at speeding labor after admission may decrease likelihoods for primary cesarean births. The NICE dilation-rate based active labor diagnostic guideline is more inclusive than Friedman or ACOG/SMFM guidelines and its use may be the most clinically-useful for improving the likelihood of vaginal birth among parous women.

Epidural Labor Analgesia and Maternal Fever

Women receiving an epidural for labor analgesia are at increased risk for intrapartum fever. This relationship has been supported by observational, before and after, and randomized controlled trials. The etiology is not well understood but is likely a result of noninfectious inflammation as studies have found women with fever have higher levels of inflammatory markers. Maternal pyrexia may change obstetric management and women are more likely to receive antibiotics or undergo cesarean delivery. Maternal pyrexia is associated with adverse neonatal outcomes. With these consequences, understanding and preventing maternal fever is imperative.

Cell-free DNA, inflammation, and the initiation of spontaneous term labor

BACKGROUND

Hypomethylated cell-free DNA from senescent placental trophoblasts may be involved in the activation of the inflammatory cascade to initiate labor.

OBJECTIVE

To determine the changes in cell-free DNA concentrations, the methylation ratio, and inflammatory markers between women in labor at term vs women without labor.

STUDY DESIGN

In this prospective cohort study, eligible participants carried a nonanomalous singleton fetus. Women with major medical comorbidity, preterm labor, progesterone use, aneuploidy, infectious disease, vaginal bleeding, abdominal trauma, or invasive procedures during the pregnancy were excluded. Maternal blood samples were collected at 28 weeks, 36 weeks, and at admission for delivery. Total cell-free DNA concentration, methylation ratio, and interleukin-6 were analyzed. The primary outcome was the difference in methylation ratio in women with labor vs without labor. Secondary outcomes included the longitudinal changes in these biomarkers corresponding to labor status.

RESULTS

A total of 55 women were included; 20 presented in labor on admission and 35 presented without labor. Women in labor had significantly greater methylation ratio (P = .001) and interleukin-6 (P < .001) on admission for delivery than women without labor. After we controlled for body mass index and maternal age, methylation ratio (adjusted relative risk, 1.38; 95% confidence interval, 1.13 to 1.68) and interleukin-6 (adjusted relative risk, 1.12, 95% confidence interval, 1.07 to 1.17) remained greater in women presenting in labor. Total cell-free DNA was not significantly different in women with labor compared with women without. Longitudinally, total cell-free DNA (P < .001 in labor, P = .002 without labor) and interleukin-6 (P < .001 in labor, P = .01 without labor) increased significantly across gestation in both groups. The methylation ratio increased significantly in women with labor from 36 weeks to delivery (P = .02).

CONCLUSION

Spontaneous labor at term is associated with a greater cell-free DNA methylation ratio and interleukin-6 compared with nonlabored controls. As gestation advances, total cell-free DNA concentrations and interleukin-6 levels increase. A greater methylation ratio reflects a greater maternal contribution (vs placental) in women with labor, likely resulting from greater levels of neutrophils, lymphocytes, and uterine activation proteins at the time of labor. Although not significant, women in labor had a greater total cell-free DNA concentration and thus could theoretically have more hypomethylated DNA available for interaction with the inflammatory cascade. Larger studies are needed to investigate this theory.

Likelihood of cesarean delivery after applying leading active labor diagnostic guidelines

BACKGROUND

Friedman, the United Kingdom's National Institute for Health and Care Excellence (NICE), and the American College of Obstetricians and Gynecologists/Society for Maternal-Fetal Medicine (ACOG/SMFM) support different active labor diagnostic guidelines. Our aims were to compare likelihoods for cesarean delivery among women admitted before vs in active labor by diagnostic guideline (within-guideline comparisons) and between women admitted in active labor per one or more of the guidelines (between-guideline comparisons).

DESIGN

Active labor diagnostic guidelines were retrospectively applied to cervical examination data from nulliparous women with spontaneous labor onset (n = 2573). Generalized linear models were used to determine outcome likelihoods within- and between-guideline groups.

RESULTS

At admission, 15.7%, 48.3%, and 10.1% of nulliparous women were in active labor per Friedman, NICE, and ACOG/SMFM diagnostic guidelines, respectively. Cesarean delivery was more likely among women admitted before vs in active labor per the Friedman (AOR 1.75 [95% CI 1.08-2.82] or NICE guideline (AOR 2.55 [95% CI 1.84-3.53]). Between guidelines, cesarean delivery was less likely among women admitted in active labor per the NICE guideline, as compared with the ACOG/SMFM guideline (AOR 0.55 [95% CI 0.35-0.88]).

CONCLUSION

Many nulliparous women are admitted to the hospital before active labor onset. These women are significantly more likely to have a cesarean delivery. Diagnosing active labor before admission or before intervention to speed labor may be one component of a multi-faceted approach to decreasing the primary cesarean rate in the United States. The NICE diagnostic guideline is more inclusive than Friedman or ACOG/SMFM guidelines and its use may be the most clinically useful for safely lowering cesarean rates.

Immunophenotyping and activation status of maternal peripheral blood leukocytes during pregnancy and labour, both term and preterm

The onset of labour in rodents and in humans is associated with physiological inflammation which is manifested by infiltration of activated maternal peripheral leukocytes (mPLs) into uterine tissues. Here, we used flow cytometry to immunophenotype mPLs throughout gestation and labour, both term and preterm. Peripheral blood was collected from non-pregnant women and pregnant women in the 1st, 2nd and 3rd trimesters. Samples were also collected from women in active labour at term (TL) or preterm (PTL) and compared with women term not-in-labour (TNIL) and preterm not-in-labour (PTNIL). Different leukocyte populations were identified by surface markers such as CD45, CD14, CD15, CD3, CD4, CD8, CD19 and CD56. Their activation status was measured by the expression levels of CD11b, CD44, CD55, CD181 and CD192 proteins. Of all circulating CD45+ leukocytes, we detected significant increases in CD15+ granulocytes (i) in pregnant women versus non-pregnant; (ii) in TL women versus TNIL and versus pregnant women in the 1st/2nd/3rd trimester; (iii) in PTL women versus PTNIL. TL was characterized by (iv) increased expressions of CD11b, CD55 and CD192 on granulocytes; (v) increased mean fluorescent intensity (MFI) of CD55 and CD192 on monocytes; (vi) increased CD44 MFI on CD3+ lymphocytes as compared to late gestation. In summary, we have identified sub-populations of mPLs that are specifically activated in association with gestation (granulocytes) or with the onset of labour (granulocytes, monocytes and lymphocytes). Additionally, beta regression analysis created a set of reference values to rank this association between immune markers of pregnancy and to identify activation status with potential prognostic and diagnostic capability.

A dynamical systems model of progesterone receptor interactions with inflammation in human parturition

BACKGROUND

Progesterone promotes uterine relaxation and is essential for the maintenance of pregnancy. Withdrawal of progesterone activity and increased inflammation within the uterine tissues are key triggers for parturition. Progesterone actions in myometrial cells are mediated by two progesterone receptor (PR) isoforms, PR-A and PR-B, that function as ligand-activated transcription factors. PR-B mediates relaxatory actions of progesterone, in part, by decreasing myometrial cell responsiveness to pro-inflammatory stimuli. These same pro-inflammatory stimuli promote the expression of PR-A which inhibits the anti-inflammatory activity of PR-B. Competitive interaction between the progesterone receptors then augments myometrial responsiveness to pro-inflammatory stimuli. The interaction between PR-B transcriptional activity and inflammation in the pregnancy myometrium is examined using a dynamical systems model in which quiescence and labor are represented as phase-space equilibrium points. Our model shows that PR-B transcriptional activity and the inflammatory load determine the stability of the quiescent and laboring phenotypes. The model is tested using published transcriptome datasets describing the mRNA abundances in the myometrium before and after the onset of labor at term. Surrogate transcripts were selected to reflect PR-B transcriptional activity and inflammation status.

RESULTS

The model coupling PR-B activity and inflammation predicts contractile status (i.e., laboring or quiescent) with high precision and recall and outperforms uncoupled single and two-gene classifiers. Linear stability analysis shows that phase space bifurcations exist in our model that may reflect the phenotypic states of the pregnancy uterus. The model describes a possible tipping point for the transition of the quiescent to the contractile laboring phenotype.

CONCLUSIONS

Our model describes the functional interaction between the PR-A:PR-B hypothesis and tissue level inflammation in the pregnancy uterus and is a first step in more sophisticated dynamical systems modeling of human partition. The model explains observed biochemical dynamics and as such will be useful for the development of a range of systems-based models using emerging data to predict preterm birth and identify strategies for its prevention.

A Role for the Inflammasome in Spontaneous Labor at Term

PROBLEM

Inflammasomes are signaling platforms that, upon sensing pathogens and sterile stressors, mediate the release of mature forms of interleukin (IL)-1β and IL-18. The aims of this study were to determine (i) the expression of major inflammasome components in the chorioamniotic membranes in spontaneous labor at term, (ii) whether there are changes in the inflammasome components associated with the activation of caspase-1 and caspase-4, and (iii) whether these events are associated with the release of the mature forms of IL-1β and IL-18.

METHOD OF STUDY

Chorioamniotic membranes were collected from women at term with and without spontaneous labor. mRNA abundance and protein concentrations of inflammasome components, nucleotide-binding oligomerization domain-containing (NOD)1 and NOD2 proteins, caspase-1, caspase-4, IL-1β, and IL-18 were quantified by qRT-PCR (n = 28-29 each), ELISA (n = 10 each) or immunoblotting (n = 8 each), and immunohistochemistry (n = 10 each). Active caspase-1 and caspase-4, as well as mature IL-18, were determined by immunoblotting (n = 4 each), and pro- and mature forms of IL-1β were determined by ELISA (n = 4-7 each).

RESULTS

Inflammasome components and NOD proteins were expressed in the chorioamniotic membranes obtained from women at term. The chorioamniotic membranes from women who underwent labor had (i) higher concentrations of NLRP3 (NOD-like receptor family, pyrin domain-containing protein 3) and NOD1 protein, (ii) greater immunoreactivity for caspase-1 and caspase-4, (iii) a greater quantity of the active form of caspase-1 (p20), and (iv) higher mRNA abundance and protein concentrations of pro- and mature IL-1β. However, mRNA abundance and protein concentrations of the mature form of IL-18 were not increased in tissues from women who underwent labor at term.

CONCLUSIONS

Spontaneous labor at term is characterized by the expression of inflammasome components, which may participate in the activation of caspase-1 and lead to the cleavage and release of mature IL-1β by the chorioamniotic membranes. These results support the participation of the inflammasome in the mechanisms responsible for spontaneous parturition at term.

Pyoderma gangrenosum and pregnancy: an example of abnormal inflammation and challenging treatment

Pyoderma gangrenosum (PG) is a neutrophil-predominant inflammatory disease that initially presents as a sterile pustule and may progress to ulcerations. Its root cause is unknown, but the presentation is commonly associated with systemic inflammatory conditions such as inflammatory bowel disease, arthritis and haematological abnormalities. On the other hand, pregnant women show a progressive neutrophilia during gestation, which culminates in a major inflammatory event to help drive labour. Although uncommonly, PG has been associated with pregnancy, which provides an additional link to systemic inflammation as an underlying cause of PG. We reviewed documented presentations of PG in gravid and post-partum patients, and have speculated on the possible pathogenesis based on their clinical presentations. Also, we summarize the reported treatments and their outcomes in these patients.

Incidence, diagnosis and management of tubal and nontubal ectopic pregnancies: a review

BACKGROUND

Ectopic pregnancy is a potentially life-threatening condition occurring in 1-2 % of all pregnancies. The most common ectopic implantation site is the fallopian tube, though 10 % of ectopic pregnancies implant in the cervix, ovary, myometrium, interstitial portion of the fallopian tube, abdominal cavity or within a cesarean section scar.

FINDINGS

Diagnosis involves a combination of clinical symptoms, serology, and ultrasound. Medical management is a safe and effective option in most clinically stable patients. Patients who have failed medical management, are ineligible, or present with ruptured ectopic pregnancy or heterotopic pregnancy are most often managed with excision by laparoscopy or, less commonly, laparotomy. Management of nontubal ectopic pregnancies may involve medical or surgical treatment, or a combination, as dictated by ectopic pregnancy location and the patient's clinical stability. Following tubal ectopic pregnancy, the rate of subsequent intrauterine pregnancy is high and independent of treatment modality.

CONCLUSION

This review describes the incidence, risk factors, diagnosis, and management of tubal and non-tubal ectopic and heterotopic pregnancies, and reviews the existing data regarding recurrence and future fertility.

Changes in the Blood Serum Levels of the Costimulatory Soluble B7-H4 Molecule in Pregnant Women During the Peripartal Phase

PROBLEM

B7-H4, a transmembrane protein that negatively regulates T lymphocytes, seems to play a role in the suppression of the im\mune response at the maternal-fetal interface. The aim of this study was to compare the blood serum concentration levels of soluble B7-H4 (sB7-H4) prepartal and postpartal in both women who experienced spontaneous onset of labor and those who underwent elective cesarian section.

METHOD OF STUDY

Blood was obtained from 30 prepartal and postpartal women who delivered at the University Hospital of Essen between 2011 and 2012. These patients were further divided into two subgroups depending on the advancement of labor. The sB7-H4 blood serum concentration levels of the women in the groups were then determined by ELISA (BIOZOL, Eching, Germany).

RESULTS

In women who underwent elective cesarian section, a significant increase in sB7-H4 blood serum concentration levels occurred postpartal, while in women who experienced spontaneous onset of labor, no differences between prepartal and postpartal concentration levels were observed. The sB7-H4 blood serum concentration levels on the day after delivery in the women who experienced spontaneous labor and those who underwent elective cesarian section were comparable; however, higher blood serum concentration levels of sB7-H4 were observed prepartal in women with spontaneous onset of labor compared to those found in the women about to undergo elective cesarian section.

CONCLUSION

These changes in sB7-H4 blood serum concentration levels suggest that this protein is involved in immunological changes associated with the spontaneous onset of labor and post-delivery homeostasis.