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Objective: To distinguish between prostaglandin and prostamide concentrations in the amniotic fluid of women who had an episode of preterm labor with intact membranes through the utilisation of liquid chromatography-tandem mass spectrometry.Study Design: Liquid chromatography-tandem mass spectrometry analysis of amniotic fluid of women with preterm labor and (1) subsequent delivery at term (2) preterm delivery without intra-amniotic inflammation; (3) preterm delivery with sterile intra-amniotic inflammation (interleukin (IL)-6>2.6 ng/mL without detectable microorganisms); and (4) preterm delivery with intra-amniotic infection [IL-6>2.6 ng/mL with detectable microorganisms].Results: (1) amniotic fluid concentrations of PGE2, PGF2α, and PGFM were higher in patients with intra-amniotic infection than in those without intra-amniotic inflammation; (2) PGE2 and PGF2α concentrations were also greater in patients with intra-amniotic infection than in those with sterile intra-amniotic inflammation; (3) patients with sterile intra-amniotic inflammation had higher amniotic fluid concentrations of PGE2 and PGFM than those without intra-amniotic inflammation who delivered at term; (4) PGFM concentrations were also greater in women with sterile intra-amniotic inflammation than in those without intra-amniotic inflammation who delivered preterm; (5) amniotic fluid concentrations of prostamides (PGE2-EA and PGF2α-EA) were not different among patients with preterm labor; (6) amniotic fluid concentrations of prostaglandins, but no prostamides, were higher in cases with intra-amniotic inflammation; and (7) the PGE2:PGE2-EA and PGF2α:PGF2α-EA ratios were higher in patients with intra-amniotic infection compared to those without inflammation.Conclusions: Mass spectrometric analysis of amniotic fluid indicated that amniotic fluid concentrations of prostaglandins, but no prostamides, were higher in women with preterm labor and intra-amniotic infection than in other patients with an episode of preterm labor. Yet, women with intra-amniotic infection had greater amniotic fluid concentrations of PGE2 and PGF2α than those with sterile intra-amniotic inflammation, suggesting that these two clinical conditions may be differentiated by using mass spectrometric analysis of amniotic fluid. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether previously established mRNA signatures are predictive of early preeclampsia when evaluated by maternal cellular transcriptome analysis in samples collected before clinical manifestation.Materials and Methods: We profiled gene expression at exon-level resolution in whole blood samples collected longitudinally from 49 women with normal pregnancy (controls) and 13 with early preeclampsia (delivery <34 weeks of gestation). After preprocessing and removal of gestational age-related trends in gene expression, data were converted into Z-scores based on the mean and standard deviation among controls for six gestational-age intervals. The average Z-scores of mRNAs in each previously established signature considered herein were compared between cases and controls at 9-11, 11-17, 17-22, 22-28, 28-32, and 32-34 weeks of gestation.Results: (1) Average expression of the 16-gene untargeted cellular mRNA signature was higher in women diagnosed with early preeclampsia at 32-34 weeks of gestation, yet more importantly, also prior to diagnosis at 28-32 weeks and 22-28 weeks of gestation, compared to controls (all, p < .05). (2) A combination of four genes from this signature, including a long non-protein coding RNA [H19 imprinted maternally expressed transcript (H19)], fibronectin 1 (FN1), tubulin beta-6 class V (TUBB6), and formyl peptide receptor 3 (FPR3) had a sensitivity of 0.85 (0.55-0.98) and a specificity of 0.92 (0.8-0.98) for prediction of early preeclampsia at 22-28 weeks of gestation. (3) H19, FN1, and TUBB6 were increased in women with early preeclampsia as early as 11-17 weeks of gestation (all, p < .05). (4) After diagnosis at 32-34 weeks, but also prior to diagnosis at 11-17 weeks, women destined to have early preeclampsia showed a coordinated increase in whole blood expression of several single-cell placental signatures, including the 20-gene signature of extravillous trophoblast (all, p < .05). (5) A combination of three mRNAs from the extravillous trophoblast signature (MMP11, SLC6A2, and IL18BP) predicted early preeclampsia at 11-17 weeks of gestation with a sensitivity of 0.83 (0.52-0.98) and specificity of 0.94 (0.79-0.99).Conclusions: Circulating early transcriptomic markers for preeclampsia can be found either by untargeted profiling of the cellular transcriptome or by focusing on placental cell-specific mRNAs. The untargeted cellular mRNA signature was consistently increased in early preeclampsia after 22 weeks of gestation, and individual mRNAs of this signature were significantly increased as early as 11-17 weeks of gestation. Several single-cell placental signatures predicted future development of the disease at 11-17 weeks and were also increased in women already diagnosed at 32-34 weeks of gestation. [ABSTRACT FROM AUTHOR]

Objective: Pyroptosis is an inflammatory form of programmed cell death that is mediated by the activation of the inflammasome and depends on the pore-forming function of gasdermin D. Therefore, the detection of gasdermin D represents in vivo evidence of pyroptosis. We recently showed that there is intra-amniotic inflammasome activation in spontaneous labor at term; however, evidence of pyroptosis is lacking. The objectives of this study were to investigate (1) whether gasdermin D is detectable in the amniotic fluid of women who delivered at term; (2) whether amniotic fluid gasdermin D concentrations are associated with the process of spontaneous labor at term; and (3) whether gasdermin D is expressed in the chorioamniotic membranes from these patients.Methods: This retrospective cross-sectional study included amniotic fluid samples from 41 women who underwent spontaneous labor at term (n = 17) or delivered at term without labor (n = 24). As a readout of pyroptosis, gasdermin D was determined in amniotic fluid samples using a specific and sensitive ELISA kit. The 90th percentile of amniotic fluid gasdermin D concentrations was calculated among women without spontaneous labor at term (reference group). The association between high amniotic fluid gasdermin D concentrations (≥90th percentile in the reference group) and spontaneous labor at term was tested using the Fisher's exact test. A p value <.05 was considered significant. Multiplex immunofluorescence staining and phenoptics (multispectral imaging) were performed to determine gasdermin D expression in the chorioamniotic membranes and to colocalize this protein with the inflammasome-related molecules caspase-1 and interleukin-1β.Results: (1) Gasdermin D is present in the amniotic fluid of women who delivered at term; (2) the 90th percentile of amniotic fluid gasdermin D concentrations in women who delivered at term without spontaneous labor was 3.4 ng/mL; (3) the proportion of women with amniotic fluid gasdermin D concentrations above the threshold was higher in those who underwent term labor than in those who delivered at term without labor; (4) amniotic fluid concentrations of gasdermin D > 3.4 ng/mL were significantly associated with the presence of spontaneous labor in women who delivered at term (odds ratio 6.0, p-value .048); and (5) the protein expression of gasdermin D is increased in the chorioamniotic membranes of women who underwent spontaneous labor at term and is colocalized with caspase-1 and IL-1β.Conclusions: Gasdermin D is increased in the amniotic fluid and chorioamniotic membranes of women who underwent spontaneous labor at term compared to those without labor. These data provide evidence implicating pyroptosis in the mechanisms that lead to the sterile inflammatory process of term parturition. [ABSTRACT FROM AUTHOR]

This paper discusses power and sample-size computation for likelihood ratio and Wald testing of the significance of covariate effects in latent class models. For both tests, asymptotic distributions can be used; that is, the test statistic can be assumed to follow a central Chi-square under the null hypothesis and a non-central Chi-square under the alternative hypothesis. Power or sample-size computation using these asymptotic distributions requires specification of the non-centrality parameter, which in practice is rarely known.We show how to calculate this non-centrality parameter using a large simulated data set from the model under the alternative hypothesis. A simulation study is conducted evaluating the adequacy of the proposed power analysis methods, determining the key study design factor affecting the power level, and comparing the performance of the likelihood ratio and Wald test. The proposed power analysis methods turn out to perform very well for a broad range of conditions. Moreover, apart from effect size and sample size, an important factor affecting the power is the class separation, implying that when class separation is low, rather large sample sizes are needed to achieve a reasonable power level. [ABSTRACT FROM AUTHOR]

Background: Activation of the coagulation system and increased thrombin generation have been implicated in the pathophysiology of preeclampsia, and this rationale supports the administration of low-molecular-weight heparin to prevent this syndrome in patients at risk. Yet randomized trials of this prophylactic measure have yielded contradictory results. One possible explanation is that only a subset of patients with preeclampsia have excessive thrombin generation and would benefit from the administration of low-molecular-weight heparin. Therefore, the key questions are whether and when patients who subsequently develop preeclampsia present evidence of abnormal thrombin generation.Objectives: The objectives of the study were to determine 1) the kinetics of thrombin generation throughout gestation in women with a normal pregnancy and in those with early and late preeclampsia, and 2) the diagnostic performance of in vivo thrombin generation parameters to predict the development of preeclampsia.Study Design: This retrospective nested case-control study was based on a prospective longitudinal cohort of singleton gestations. Cases comprised women who developed preeclampsia (n=49) and controls consisted of patients with a normal pregnancy (n=45). Preeclampsia was classified into early onset (n=24) and late onset (n=25). The longitudinal changes in the parameters of the thrombin generation assay (lag time, time to peak thrombin concentration, peak thrombin concentration, endogenous thrombin generation, and velocity index) throughout gestation were compared between the study groups, and the normal pregnancy percentiles were derived from the control group. We tested whether a single parameter or a combination of parameters derived from the kinetics of thrombin generation could identify patients who subsequently developed preeclampsia. Time-related parameters <10th percentile were considered short, and concentration-related parameters >90th percentile were considered high.Results: 1) Patients who developed preeclampsia (early- and late-onset) had abnormal thrombin generation kinetics as early as 8-16 weeks of gestation; 2) patients with a combination of a short lag time and a high peak thrombin concentration at 8-16 weeks gestation had an odds ratio (OR) of 43.87 for the subsequent development of preeclampsia [area under the curve (AUC) 0.79; sensitivity 56.8%; specificity 92.7%; positive likelihood ratio 7.76]; 3) at 16-22 weeks of gestation, patients with a combination of a short lag time with a high velocity index had an OR of 16 for the subsequent development of preeclampsia (AUC 0.78; sensitivity 62.2%; specificity 92.5%; positive likelihood ratio 8.29).Conclusion: During early pregnancy, the thrombin generation assay can identify the subset of patients at greater risk for the development of preeclampsia due to accelerated and enhanced production of thrombin. This observation provides a rationale for testing the efficacy of low-molecular-weight heparin in this subset of patients. We propose that future research on the efficacy of low-molecular-weight heparin and other interventions targeting the coagulation system to prevent preeclampsia should be focused on patients with abnormal kinetics of thrombin generation. [ABSTRACT FROM AUTHOR]

Latent Markov (LM) models are increasingly used in a wide range of research areas including psychological, sociological, educational, and medical sciences. Methods to perform power computations are lacking, however. This article presents methods for preforming power analysis in LM models. Two cases of tests of hypotheses on the transition parameters of LM models are considered. The first case concerns the situation where the likelihood ratio test statistic follows a chi-square distribution, implying that the power computation can also be based on this theoretical distribution. In the second case, power needs to be computed based on empirical distributions constructed via Monte Carlo methods. Numerical studies are conducted to illustrate the proposed power computation methods and to investigate design factors affecting the power of this test. [ABSTRACT FROM PUBLISHER]

Objective: Preeclampsia, one of the most serious obstetric complications, is a heterogenous disorder resulting from different pathologic processes. However, placental oxidative stress and an anti-angiogenic state play a crucial role. Mitochondria are a major source of cellular reactive oxygen species. Abnormalities in mitochondrial structures, proteins, and functions have been observed in the placentae of patients with preeclampsia, thus mitochondrial dysfunction has been implicated in the mechanism of the disease. Mitochondrial nuclear retrograde regulator 1 (MNRR1) is a newly characterized bi-organellar protein with pleiotropic functions. In the mitochondria, this protein regulates cytochrome c oxidase activity and reactive oxygen species production, whereas in the nucleus, it regulates the transcription of a number of genes including response to tissue hypoxia and inflammatory signals. Since MNRR1 expression changes in response to hypoxia and to an inflammatory signal, MNRR1 could be a part of mitochondrial dysfunction and involved in the pathologic process of preeclampsia. This study aimed to determine whether the plasma MNRR1 concentration of women with preeclampsia differed from that of normal pregnant women., Methods: This retrospective case-control study included 97 women with preeclampsia, stratified by gestational age at delivery into early (<34 weeks, n  = 40) and late (≥34 weeks, n  = 57) preeclampsia and by the presence or absence of placental lesions consistent with maternal vascular malperfusion (MVM), the histologic counterpart of an anti-angiogenic state. Women with an uncomplicated pregnancy at various gestational ages who delivered at term served as controls ( n  = 80) and were further stratified into early ( n  = 25) and late ( n  = 55) controls according to gestational age at venipuncture. Maternal plasma MNRR1 concentrations were determined by an enzyme-linked immunosorbent assay., Results: 1) Women with preeclampsia at the time of diagnosis (either early or late disease) had a significantly higher median (interquartile range, IQR) plasma MNRR1 concentration than the controls [early preeclampsia: 1632 (924-2926) pg/mL vs. 630 (448-4002) pg/mL, p  = .026, and late preeclampsia: 1833 (1441-5534) pg/mL vs. 910 (526-6178) pg/mL, p  = .021]. Among women with early preeclampsia, those with MVM lesions in the placenta had the highest median (IQR) plasma MNRR1 concentration among the three groups [with MVM: 2066 (1070-3188) pg/mL vs. without MVM: 888 (812-1781) pg/mL, p  = .03; and with MVM vs. control: 630 (448-4002) pg/mL, p  = .04]. There was no significant difference in the median plasma MNRR1 concentration between women with early preeclampsia without MVM lesions and those with an uncomplicated pregnancy ( p  = .3). By contrast, women with late preeclampsia, regardless of MVM lesions, had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM: 1609 (1392-3135) pg/mL vs. control: 910 (526-6178), p  = .045; and without MVM: 2023 (1578-8936) pg/mL vs. control, p  = .01]., Conclusions: MNRR1, a mitochondrial regulator protein, is elevated in the maternal plasma of women with preeclampsia (both early and late) at the time of diagnosis. These findings may reflect some degree of mitochondrial dysfunction, intravascular inflammation, or other unknown pathologic processes that characterize this obstetrical syndrome.

Objective: COVID-19 has been reported to increase the risk of prematurity, however, due to the frequent absence of unaffected controls as well as inadequate accounting for confounders in many studies, the question requires further investigation. We sought to determine the impact of COVID-19 disease on preterm birth (PTB) overall, as well as related subcategories such as early prematurity, spontaneous, medically indicated preterm birth, and preterm labor (PTL). We assessed the impact of confounders such as COVID-19 risk factors, a-priori risk factors for PTB, symptomatology, and disease severity on rates of prematurity., Methods: This was a retrospective cohort study of pregnant women from March 2020 till October 1st, 2020. The study included patients from 14 obstetric centers in Michigan, USA. Cases were defined as women diagnosed with COVID-19 at any point during their pregnancy. Cases were matched with uninfected women who delivered in the same unit, within 30 d of the delivery of the index case. Outcomes of interest were frequencies of prematurity overall and subcategories of preterm birth (early, spontaneous/medically indicated, preterm labor, and premature preterm rupture of membranes) in cases compared to controls. The impact of modifiers of these outcomes was documented with extensive control for potential confounders. A p value <.05 was used to infer significance., Results: The rate of prematurity was 8.9% in controls, 9.4% in asymptomatic cases, 26.5% in symptomatic COVID-19 cases, and 58.8% among cases admitted to the ICU. Gestational age at delivery was noted to decrease with disease severity. Cases were at an increased risk of prematurity overall [adjusted relative risk (aRR) = 1.62 (1.2-2.18)] and of early prematurity (<34 weeks) [aRR = 1.8 (1.02-3.16)] when compared to controls. Medically indicated prematurity related to preeclampsia [aRR = 2.46 (1.47-4.12)] or other indications [aRR = 2.32 (1.12-4.79)], were the primary drivers of overall prematurity risk. Symptomatic cases were at an increased risk of preterm labor [aRR = 1.74 (1.04-2.8)] and spontaneous preterm birth due to premature preterm rupture of membranes [aRR = 2.2(1.05-4.55)] when compared to controls and asymptomatic cases combined. The gestational age at delivery followed a dose-response relation with disease severity, as more severe cases tended to deliver earlier (Wilcoxon p < .05)., Conclusions: COVID-19 is an independent risk factor for preterm birth. The increased preterm birth rate in COVID-19 was primarily driven by medically indicated delivery, with preeclampsia as the principal risk factor. Symptomatic status and disease severity were significant drivers of preterm birth.

Objective: Pyroptosis is an inflammatory form of programmed cell death that is mediated by the activation of the inflammasome and depends on the pore-forming function of gasdermin D. Therefore, the detection of gasdermin D represents in vivo evidence of pyroptosis. We recently showed that there is intra-amniotic inflammasome activation in spontaneous labor at term; however, evidence of pyroptosis is lacking. The objectives of this study were to investigate (1) whether gasdermin D is detectable in the amniotic fluid of women who delivered at term; (2) whether amniotic fluid gasdermin D concentrations are associated with the process of spontaneous labor at term; and (3) whether gasdermin D is expressed in the chorioamniotic membranes from these patients. Methods: This retrospective cross-sectional study included amniotic fluid samples from 41 women who underwent spontaneous labor at term ( n  = 17) or delivered at term without labor ( n  = 24). As a readout of pyroptosis, gasdermin D was determined in amniotic fluid samples using a specific and sensitive ELISA kit. The 90th percentile of amniotic fluid gasdermin D concentrations was calculated among women without spontaneous labor at term (reference group). The association between high amniotic fluid gasdermin D concentrations (≥90th percentile in the reference group) and spontaneous labor at term was tested using the Fisher's exact test. A p value <.05 was considered significant. Multiplex immunofluorescence staining and phenoptics (multispectral imaging) were performed to determine gasdermin D expression in the chorioamniotic membranes and to colocalize this protein with the inflammasome-related molecules caspase-1 and interleukin-1β. Results: (1) Gasdermin D is present in the amniotic fluid of women who delivered at term; (2) the 90th percentile of amniotic fluid gasdermin D concentrations in women who delivered at term without spontaneous labor was 3.4 ng/mL; (3) the proportion of women with amniotic fluid gasdermin D concentrations above the threshold was higher in those who underwent term labor than in those who delivered at term without labor; (4) amniotic fluid concentrations of gasdermin D > 3.4 ng/mL were significantly associated with the presence of spontaneous labor in women who delivered at term (odds ratio 6.0, p -value .048); and (5) the protein expression of gasdermin D is increased in the chorioamniotic membranes of women who underwent spontaneous labor at term and is colocalized with caspase-1 and IL-1β. Conclusions: Gasdermin D is increased in the amniotic fluid and chorioamniotic membranes of women who underwent spontaneous labor at term compared to those without labor. These data provide evidence implicating pyroptosis in the mechanisms that lead to the sterile inflammatory process of term parturition.