Historical evolution of ideas on eclampsia/preeclampsia: A proposed optimistic view of preeclampsia

The endocannabinoidome in human placenta: Possible contribution to the pathogenesis of preeclampsia

Preeclampsia (PE) was first reported thousands of years ago, yet there is still a shortage of biomarkers to determine the severity and type of PE. The importance of the expanded endocannabinoid system, or endocannabinoidome (eCBome), has emerged recently in placental physiology and pathology, though the potential alterations of the eCBome in PE have not been fully explored. Analysis by qRT-PCR using placental samples of normotensive and PE women demonstrate for the first time the presence of ABHD4, GDE1, and DAGLβ in both normotensive and PE placental tissues. Interestingly, NAPE-PLD, FAAH-1, DAGLα, MAGL, and ABHD6 mRNA levels were increased in the placental tissues of PE patients. Quantification in plasma and placental tissues showed a decrease for anandamide (AEA), N-oleoylethanolamine (OEA), and N-docosahexaenoylethanolamine (DHEA) in the placenta, accompanied only by a decrease in plasma levels of AEA. In addition, a strong negative correlation was obtained between OEA and the biomarker of PE, soluble fms-like tyrosine kinase-1. Given the inflammatory nature of PE and the anti-inflammatory role of OEA and DHEA, the decrease in the local levels of these mediators may underlie the inflammatory component of this pathology. Additionally, lower AEA levels in both placenta and plasma may contribute to the atypical alterations of the spiral arteries in PE due to the vasorelaxation effects of AEA. These results add new information to the role of the eCBome members in placental development, while also pointing to a potential role as biomarkers of PE.

Augmented Intelligence for Clinical Discovery in Hypertensive Disorders of Pregnancy Using Outlier Analysis

Objectives Clinical discoveries are heralded by observing unique and unusual clinical cases. The effort of identifying such cases rests on the shoulders of busy clinicians. We assess the feasibility and applicability of an augmented intelligence framework to accelerate the rate of clinical discovery in preeclampsia and hypertensive disorders of pregnancy-an area that has seen little change in its clinical management. Methods We conducted a retrospective exploratory outlier analysis of participants enrolled in the folic acid clinical trial (FACT, N=2,301) and the Ottawa and Kingston birth cohort (OaK, N=8,085). We applied two outlier analysis methods: extreme misclassification contextual outlier and isolation forest point outlier. The extreme misclassification contextual outlier is based on a random forest predictive model for the outcome of preeclampsia in FACT and hypertensive disorder of pregnancy in OaK. We defined outliers in the extreme misclassification approach as mislabelled observations with a confidence level of more than 90%. Within the isolation forest approach, we defined outliers as observations with an average path length z score less or equal to -3, or more or equal to 3. Content experts reviewed the identified outliers and determined if they represented a potential novelty that could conceivably lead to a clinical discovery. Results In the FACT study, we identified 19 outliers using the isolation forest algorithm and 13 outliers using the random forest extreme misclassification approach. We determined that three (15.8%) and 10 (76.9%) were potential novelties, respectively. Out of 8,085 participants in the OaK study, we identified 172 outliers using the isolation forest algorithm and 98 outliers using the random forest extreme misclassification approach; four (2.3%) and 32 (32.7%), respectively, were potential novelties. Overall, the outlier analysis part of the augmented intelligence framework identified a total of 302 outliers. These were subsequently reviewed by content experts, representing the human part of the augmented intelligence framework. The clinical review determined that 49 of the 302 outliers represented potential novelties.  Conclusions Augmented intelligence using extreme misclassification outlier analysis is a feasible and applicable approach for accelerating the rate of clinical discoveries. The use of an extreme misclassification contextual outlier analysis approach has resulted in a higher proportion of potential novelties than using the more traditional point outlier isolation forest approach. This finding was consistent in both the clinical trial and real-world cohort study data. Using augmented intelligence through outlier analysis has the potential to speed up the process of identifying potential clinical discoveries. This approach can be replicated across clinical disciplines and could exist within electronic medical records systems to automatically identify outliers within clinical notes to clinical experts.

Do Case Reports and Case Series Generate Clinical Discoveries About Preeclampsia? A Systematic Review

Background

Preeclampsia is a leading cause of maternal and perinatal mortality and morbidity. The management of preeclampsia has not changed much in more than two decades, and its aetiology is still not fully understood. Case reports and case series have traditionally been used to communicate new knowledge about existing conditions. Whether this is true for preeclampsia is not known.

Objective

To determine whether recent case reports or case series have generated new knowledge and clinical discoveries about preeclampsia.

Methods

A detailed search strategy was developed in consultation with a medical librarian. Two bibliographic databases were searched through Ovid: Embase and MEDLINE. We selected case reports or case series published between 2015 and 2020, comprising pregnant persons diagnosed with hypertensive disorders of pregnancy, including preeclampsia. Two reviewers independently screened all publications. One reviewer extracted data from included studies, while another conducted a quality check of extracted data. We developed a codebook to guide our data extraction and outcomes assessment. The quality of each report was determined based on Joanna Briggs Institute (JBI) critical appraisal checklist for case reports and case series.

Results

We included 104 case reports and three case series, together comprising 118 pregnancies. A severe presentation or complication of preeclampsia was reported in 81% of pregnancies, and 84% had a positive maternal outcome, free of death or persistent complications. Only 8% of the case reports were deemed to be of high quality, and 53.8% of moderate quality; none of the case series were of high quality. A total of 26 of the 107 publications (24.3%) included a novel clinical discovery as a central theme.

Conclusion

Over two-thirds of recent case reports and case series about preeclampsia do not appear to present new knowledge or discoveries about preeclampsia, and most are of low quality.

Prevalence, maternal characteristics, and birth outcomes of preeclampsia: A cross-sectional study in a single tertiary healthcare center in greater Kuala Lumpur Malaysia

Background

Preeclampsia is associated with an increased risk of adverse maternal and perinatal outcomes. This study aimed to assess preeclampsia prevalence in a Malaysian referral maternity hospital and the association between preeclampsia and maternal characteristics and outcomes.

Methods

A cross-sectional study was conducted between January 2010 and December 2020 using secondary data from a single tertiary healthcare center in Greater Kuala Lumpur, Malaysia. A total of 40,212 deliveries were included for analysis to investigate the association between conditions (maternal characteristics and adverse birth outcomes) and preeclampsia. Multivariable logistic regression was conducted to assess the association between multiple independent variables and the outcome variable (preeclampsia).

Results

The reported prevalence of preeclampsia was 1.6%. Pregnant women with preeclampsia had a higher risk of preterm delivery (67.7%), instrumental and cesarean delivery (74.7%), neonatal low birth weight (48.5%), neonatal 5-min Apgar score <7 (18.1%), and neonatal intensive care unit (NICU) admission (19.8%). There were significantly higher odds of developing preeclampsia among nullipara [adjusted odd ratio (adjOR) 1.792, 95% CI: 1.518-2.115], women with a previous history of preeclampsia (adjOR 5.345, 95% CI: 2.670-10.698) and women with multiple pregnancies (adjOR 1.658, 95% CI: 1.071-2.566). However, there is a significant association between maternal characteristic variables. There was a significant association when a combination of variables for risk assessment: the presence of anemia and gestational hypertension effect on preeclampsia (OR 26.344, 95% CI: 9.775-70.993, p < 0.002) and gestational hypertension without anemia on preeclampsia (OR 3.084, 95% CI: 2.240-4.245, p < 0.001). Similarly, an association was seen between chronic hypertension and younger age (<35 years old) on preeclampsia (OR 14.490, 95% CI: 9.988-21.021, p < 0.001), and having chronic hypertension with advanced maternal age (≥35 years old) on preeclampsia (OR 5.174, 95% CI: 3.267-8.195, p < 0.001). Both conditions had increased odds of preeclampsia, in varying magnitudes. Overall, the significant interaction effects suggest that a history of chronic or gestational hypertension has a different relationship to the incidence of preeclampsia depending on the maternal age and anemia status. Pregnant women with preeclampsia had significantly higher odds for preterm delivery (adjOR 6.214, 95% CI: 5.244-7.364), instrumental and cesarean delivery (adjOR 4.320, 95% CI: 3.587-5.202), neonatal low birth weight (adjOR 7.873, 95% CI: 6.687-9.271), 5-min Apgar score <7 (adjOR 3.158, 95% CI: 2.130-4.683), and NICU admission (adjOR 8.778, 95% CI: 7.115-10.830).

Conclusions

Nulliparity, previous history of preeclampsia, and multiple pregnancies were associated with an increased risk of preeclampsia. The presence of different underlying conditions, such as chronic hypertension, anemia, and extremes of maternal age played an important role in increasing preeclampsia risk in the considered study. Larger samples are needed to validate such findings.

Impact of gestational hypertension and pre-eclampsia on preterm birth in China: a large prospective cohort study

OBJECTIVE

To investigate the impact of gestational hypertension and pre-eclampsia on preterm birth.

DESIGN

The data were collected from the China-US Collaborative Project for Neural Tube Defect Prevention; this was a large population-based cohort study.

SETTING AND PARTICIPANTS

We selected participants registered in two southern provinces, for whom we had exact information on gestational blood pressure and pregnancy outcomes, and who were not affected by chronic hypertension. In total, 200 103 participants were recruited from 1993 to 1995.

OUTCOME MEASURES

Preterm birth was defined as a singleton pregnancy and birth before 37 gestational weeks.

RESULTS

The incidences of gestational hypertension and pre-eclampsia were 5.47% and 5.44%, respectively, for women who gave birth at full term, and 5.63% and 7.33%, respectively, for those who gave birth preterm. After adjusting for potential confounders, the risk ratios (RRs) of preterm birth in women with gestational hypertension and pre-eclampsia were 1.04 (95% CI 0.98 to 1.11) and 1.39 (95% CI 1.25 to 1.55), respectively. The associations were stronger for early-onset (<28 weeks of gestation) gestational hypertension (adjusted RR=2.13, 95% CI 1.71 to 2.65) and pre-eclampsia (adjusted RR=8.47, 95% CI 5.59 to 12.80).

CONCLUSIONS

Pre-eclampsia was associated with a higher risk of preterm birth. The early-onset gestational hypertension and pre-eclampsia were associated with more severe risks than late-onset conditions.

Periconceptional 1,3-butanediol supplementation suppresses the superimposed preeclampsia-like phenotype in the Dahl salt-sensitive rat

Preeclampsia is a hypertensive pregnancy disorder with no treatment beyond management of symptoms and delivery of the fetus and placenta. Chronic hypertension increases the risk of developing superimposed preeclampsia. Previous reports showed that 1,3-butanediol attenuates hypertension in rodents; however, the therapeutic potential of 1,3-butanediol for the prevention of preeclampsia has not been investigated. This study tested the hypothesis that attenuating hypertension before pregnancy and through the placentation period via 1,3-butanediol prevents the onset of preeclampsia in female Dahl salt-sensitive (SS/Jr) rats. Female Dahl SS/Jr rats were divided into two groups: 1,3-butanediol treated (20% via drinking water) and control (ad libitum water). Both groups were maintained on low-salt rodent chow (Teklad 7034, 0.3% NaCl; n = 8/group). Animals were treated with 1,3-butanediol for 7 wk (baseline), mated, and treated through day 12 of pregnancy. 1,3-Butanediol treatment increased plasma β-hydroxybutyrate (metabolite of 1,3-butanediol) that negatively correlated with maternal body weight in late pregnancy. Mean arterial pressure was lower in the treated group at baseline, early, and mid pregnancy, but no difference was observed in late pregnancy after treatment ended. Uterine artery resistance index (UARI) was reduced in the treated dams. No adverse fetal effects were observed, and there were no differences in pup weight or length. Placentas from treated dams had decreased vascular endothelial growth factor levels as well as decreased placental basal zone thickness and increased labyrinth zone thickness. These findings support the therapeutic role of physiological ketosis via 1,3-butanediol as a potential therapeutic approach for managing chronic hypertension, thereby preventing and mitigating adverse pregnancy outcomes associated with preeclampsia.NEW & NOTEWORTHY A ketogenic diet or increased β-hydroxybutyrate levels can reduce hypertension, but the potential of 1,3-butanediol, a β-hydroxybutyrate precursor, for treatment of preeclampsia is unknown. We hypothesized that attenuating hypertension before and during pregnancy via 1,3-butanediol prevents preeclampsia in Dahl Salt-sensitive rats. 1,3-Butanediol significantly lowered blood pressure and improved uterine artery resistance with no observable adverse fetal effects. Physiological ketosis via 1,3-butanediol may be a potential therapeutic approach for managing hypertension and mitigating adverse pregnancy outcomes.

Progress in the understanding of the pathophysiology of immunologic maladaptation related to early-onset preeclampsia and metabolic syndrome related to late-onset preeclampsia

Among mammalian species, human reproduction has 2 outstanding features. The human hemochorial placentation is characterized by a very deep endovascular trophoblast invasion in the spiral arteries, reaching deep into the myometrium. This requires an agonistic direct cell-cell interaction between the maternal immune system and semiallogeneic trophoblast. The second feature is preeclampsia, a heterogeneous syndrome, a uniquely human condition. The human female is one of the few mammals exposed to her partner's semen on multiple occasions before conception. Regulatory T cells, especially paternal antigen-specific regulatory T cells, play an important role in the maintenance of pregnancy. Sexual intercourse increases the number of dendritic cells in the uterus that play an important role in the induction of paternal antigen-specific regulatory T cells. Paternal antigen-specific regulatory T cells maintain pregnancy by inducing tolerance. In the decidua basalis of preeclamptic cases, clonal regulatory T cells are reduced; these would normally monoclonally expand to recognize fetal or paternal antigens. Programmed cell death-1 expressed on T cells regulate cytotoxic T-cell activity and protect the fetus against maternal rejection. Programmed cell death-1 expression on clonal cytotoxic T cells is reduced in preeclampsia especially in early-onset preeclampsia, making the fetus and placenta vulnerable to attack by cytotoxic T cells. These phenomena can explain the epidemiologic phenomenon that preeclampsia is more common in couples using condom contraception, with shorter cohabitation periods, first pregnancies, first pregnancies in multiparous women when they change partner, and pregnancies after assisted reproduction using donated gametes. In contrast to its importance in early-onset preeclampsia, shallow trophoblast invasion does not play a role in the development of preeclampsia, that is, immune maladaptation does not seem to be involved. Late-onset preeclampsia (>34 weeks' gestation), representing 80% to 90% of preeclampsia in most developed countries with a "Western lifestyle," is strongly associated with maternal cardiometabolic variables (metabolic syndrome). Although the underlying pathophysiology might be quite different, syncytiotrophoblast stress is the final common pathway leading to the maternal syndrome among the subtypes of preeclampsia by causing an imbalance between proangiogenic factors (placental growth factor and vascular endothelial growth factor) and antiangiogenic factors (soluble fms-like tyrosine kinase-1 and soluble endoglin). Low-dose aspirin, started before 16 week's gestation, will prevent up to 60% of early-onset preeclampsia but will not prevent late-onset preeclampsia. Optimizing prepregnancy weight and controlling gestational weight gain may be the most effective ways to prevent preeclampsia.

Proteinuria during pregnancy: definition, pathophysiology, methodology, and clinical significance

Qualitative and quantitative measurement of urine protein excretion is one of the most common tests performed during pregnancy. For more than 100 years, proteinuria was necessary for the diagnosis of preeclampsia, but recent guidelines recommend that proteinuria is sufficient but not necessary for the diagnosis. Still, in clinical practice, most patients with gestational hypertension will be diagnosed as having preeclampsia based on the presence of proteinuria. Although the reference standard for measuring urinary protein excretion is a 24-hour urine collection, spot urine protein-to-creatinine ratio is a reasonable "rule-out" test for proteinuria. Urine dipstick screening for proteinuria does not provide any clinical benefit and should not be used to diagnose proteinuria. The classic cutoff cited to define proteinuria during pregnancy is a value of >300 mg/24 hours or a urine protein-to-creatinine ratio of at least 0.3. Using this cutoff, the rate of isolated proteinuria in pregnancy may reach 8%, whereas preeclampsia occurs among 3% to 8% of pregnancies. Although this threshold is widely accepted, its origin is not based on evidence on adverse pregnancy outcomes but rather on expert opinion and results of small studies. After reviewing the available data, the most important factor that influences maternal and neonatal outcome is the severity of blood pressures and presence of end organ damage, rather than the excess protein excretion. Because the management of gestational hypertension and preeclampsia without severe features is almost identical in frequency of surveillance and timing of delivery, the separation into 2 disorders is unnecessary. If the management of women with gestational hypertension with a positive assessment of proteinuria will not change, we believe that urine assessment for proteinuria is unnecessary in women who develop new-onset blood pressure at or after 20 weeks' gestation. Furthermore, we do not recommend repeated measurement of proteinuria for women with preeclampsia, the amount of proteinuria does not seem to be related to poor maternal and neonatal outcomes, and monitoring proteinuria may lead to unindicated preterm deliveries and related neonatal complications. Our current diagnosis of preeclampsia in women with chronic kidney disease may be based on a change in protein excretion, a baseline protein excretion evaluation is critical in certain conditions such as chronic hypertension, diabetes, and autoimmune or other renal disorders. The current definition of superimposed preeclampsia possesses a diagnostic dilemma, and it is unclear whether a change in the baseline proteinuria reflects another systemic disease such as preeclampsia or whether women with chronic disease such as chronic hypertension or diabetes will experience a different "normal" pattern of protein excretion during pregnancy. Finally, limited data are available regarding angiogenic and other biomarkers in women with chronic kidney disease as a potential aid in distinguishing the worsening of baseline chronic kidney disease and chronic hypertension from superimposed preeclampsia.

Preeclampsia and eclampsia: the conceptual evolution of a syndrome

Preeclampsia, one of the most enigmatic complications of pregnancy, is considered a pregnancy-specific disorder caused by the placenta and cured only by delivery. This article traces the condition from its origins-once thought to be a disease of the central nervous system, recognized by the occurrence of seizures (ie, eclampsia)-to the present time when preeclampsia is conceptualized primarily as a vascular disorder. We review the epidemiologic data that led to the recommendation to use diastolic hypertension and proteinuria as diagnostic criteria, as their combined presence was associated with an increased risk of fetal death and the birth of small-for-gestational-age neonates. However, preeclampsia is a multisystemic disorder with protean manifestations, and the condition can be present even in the absence of hypertension and proteinuria. Toxins gaining access to the maternal circulation have been proposed to mediate the clinical manifestations-hence, the term "toxemia of pregnancy," which was used for several decades. The search for putative toxins has challenged investigators for more than a century, and a growing body of evidence suggests that products of an ischemic or a stressed placenta are responsible for the vascular changes that characterize this syndrome. The discovery that the placenta can produce antiangiogenic factors, which regulate endothelial cell function and induce intravascular inflammation, has been a major step forward in the understanding of preeclampsia. We view the release of antiangiogenic factors by the placenta as an adaptive response to improve uterine perfusion by modulating endothelial function and maternal cardiovascular performance. However, this homeostatic response can become maladaptive and lead to damage of target organs during pregnancy or the postpartum period. Early-onset preeclampsia has many features in common with atherosclerosis, whereas late-onset preeclampsia seems to result from a mismatch of fetal demands and maternal supply, that is, a metabolic crisis. Preeclampsia, as it is understood today, is essentially vascular dysfunction unmasked or caused by pregnancy. A subset of patients diagnosed with preeclampsia are at greater risk of the subsequent development of hypertension, ischemic heart disease, heart failure, vascular dementia, and end-stage renal disease. However, these adverse events may be the result of a preexisting vascular pathologic process; it is not known if the occurrence of preeclampsia increases the baseline risk. Therefore, the understanding, prediction, prevention, and treatment of preeclampsia are healthcare priorities.

Primipaternities and human birthweights

OBJECTIVES

To investigate in singleton multiparous pregnancies the effect of having a new father for an index pregnancy on new-borns' birthweights and intrauterine growth restriction.

DESIGN

20 year-observational cohort study (2001-2020).

SETTINGS

Centre Hospitalier Universitaire Hospitalier Sud Reunion's maternity (French overseas department, Indian Ocean).

MAIN OUTCOMES AND MEASURES

Comparing the 811 multiparas (cases) who had a new partner with the 49,712 who did not (controls), there were no differences concerning maternal age, education, ovulation induction/IVF, previous miscarriages, exams during pregnancies, pre-pregnancy BMI, gestational diabetes, and chronic hypertension. Cases had more previous pregnancies than controls (gravidity 4.2 vs 2.8, p < 0.001), volunteer abortions (OR1.93, p < 0.001), in vitro fecundations (OR 4.34, p < 0.001), were more likely to be unmarried (OR 2.94, p < 0.001) smoker (OR 2.2, p < 0.0001) and consuming alcohol during pregnancy (OR 2.35, p = 0.001). Cases had a much higher risk of preeclampsia than controls (OR 3.94, p < 0.001), especially early-onset preeclampsia (< 34 weeks) with an OR 4.1 (p < 0.001). Controlling for confounding factors (preeclampsia, smoking, alcohol use, early prematurity < 33 weeks, maternal ethnicity), primipaternity was an independent factor for small for gestational age newborns (OR 1.48, p < 0.001).

CONCLUSIONS

It has been known for decades that primiparas have lighter babies than multiparas. Primipaternity represents also a risk for lower birth weights. Human birthweight seems to be linked with a "couple habituation" (to paternal genes) which may be not fully established in the first pregnancy of the couple.

Functional Analysis of p21Cip1/CDKN1A and Its Family Members in Trophoblastic Cells of the Placenta and Its Roles in Preeclampsia

Preeclampsia (PE), a gestational hypertensive disease originating from the placenta, is characterized by an imbalance of various cellular processes. The cell cycle regulator p21^Cip1/CDKN1A (p21) and its family members p27 and p57 regulate signaling pathways fundamental to placental development. The aim of the present study was to enlighten the individual roles of these cell cycle regulators in placental development and their molecular involvement in the pathogenesis of PE. The expression and localization of p21, phospho-p21 (Thr-145), p27, and p57 was immunohistochemically analyzed in placental tissues from patients with early-onset PE, early-onset PE complicated by the HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome as well as late-onset PE compared to their corresponding control tissues from well-matched women undergoing caesarean sections. The gene level was evaluated using real-time quantitative PCR. We demonstrate that the delivery mode strongly influenced placental gene expression, especially for CDKN1A (p21) and CDKN1B (p27), which were significantly upregulated in response to labor. Cell cycle regulators were highly expressed in first trimester placentas and impacted by hypoxic conditions. In support of these observations, p21 protein was abundant in trophoblast organoids and hypoxia reduced its gene expression. Microarray analysis of the trophoblastic BeWo cell line depleted of p21 revealed various interesting candidate genes and signaling pathways for the fusion process. The level of p21 was reduced in fusing cytotrophoblasts in early-onset PE placentas and depletion of p21 led to reduced expression of fusion-related genes such as syncytin-2 and human chorionic gonadotropin (β-hCG), which adversely affected the fusion capability of trophoblastic cells. These data highlight that cell cycle regulators are important for the development of the placenta. Interfering with p21 influences multiple pathways related to the pathogenesis of PE.

Interpregnancy interval and hypertensive disorders of pregnancy: A population-based cohort study

BACKGROUND

Despite extensive research on risk factors and mechanisms, the extent to which interpregnancy interval (IPI) affects hypertensive disorders of pregnancy in high-income countries remains unclear.

OBJECTIVES

To examine the association between IPI and hypertensive disorders of pregnancy in a high-income country setting using both within-mother and between-mother comparisons.

METHODS

A retrospective population-based cohort study was conducted among 103 909 women who delivered three or more consecutive singleton births (n = 358 046) between 1980 and 2015 in Western Australia. We used conditional Poisson regression with robust variance, matching intervals of the same mother and adjusted for factors that vary within-mother across pregnancies, to investigate the association between IPI categories (reference 18-23 months), and the risk of hypertensive disorders of pregnancy. For comparison with previous studies, we also applied unmatched Poisson regression (between-mother analysis).

RESULTS

The incidence of preeclampsia and gestational hypertension during the study period was 4%, and 2%, respectively. For the between-mother comparison, mothers with intervals of 6-11 months had lower risk of preeclampsia with adjusted relative risk (RR) 0.92 (95% confidence interval [CI] 0.85, 0.98) compared to reference category of 18-23 months. With the within-mother matched design, we estimated a larger effect of long IPI on risk of preeclampsia (RR 1.29, 95% CI 1.18, 1.42 for 60-119 months; and RR 1.30, 95% CI 1.10, 1.53 for intervals ≥120 months) compared to 18-23 months. Short IPIs were not associated with hypertensive disorders of pregnancy.

CONCLUSIONS

In our cohort, longer IPIs were associated with increased risk of preeclampsia. However, there was insufficient evidence to suggest that short IPIs (<6 months) increase the risks of hypertensive disorders of pregnancy.

Expression of tissue factor and thrombomodulin in the placentas of pregnancies affected by early-onset and late-onset preeclampsia

AIM

To analyze the differential genetic expression and protein localization of thrombomodulin (THBD) and tissue factor (F3) in the placentas of pregnancies affected by preeclampsia.

METHODS

We assessed the expression of THBD and F3 by immunohistochemistry and real-time polymerase chain reaction (PCR) in placentas from 20 PE cases: 10 early-onset PE placentas, 10 late-onset PE placentas, and 10 control cases (normal pregnancies).

RESULTS

In cases, we found higher THBD and F3 RNA levels in placental tissue. Protein expression in controls differed from that in late-onset PE placentas, which had lower THBD levels in syncytiotrophoblasts and amniotic cells. Likewise, late-onset PE placentas exhibited comparatively lower F3 expression in the perivillous fibrin. In contrast, early-onset PE had high F3 expression in the subdecidual fibrin. We found no significant differences in the F3/THBD ratio between the groups.

CONCLUSION

Our study supports evidence that shows the involvement of F3 and THBD in placental disorders. Furthermore, this finding contributes to a better understanding of the physio-pathological role that these molecules may play in the development of this heterogeneous disease.

Shedding light on the pathophysiology of preeclampsia-syndrome in the era of Cardio-Obstetrics: Role of inflammation and endothelial dysfunction

:

Preeclampsia (PE) is a worldwide pregnancy complication with serious maternal and neonatal consequences. Our understanding of PE pathophysiology has significantly evolved over the last decades by recognizing that endothelial dysfunction and systemic inflammation, with an associated angiogenic imbalance, are key pieces of this still incomplete puzzle. In the present era, where no single treatment to cure or treat this obstetric condition has been developed so far, PE prevention and early prediction poses the most useful clinical approach to reduce the PE burden. Although most PE episodes occur in healthy nulliparous women, the identification of specific clinical conditions that increase dramatically the risk of PE provides a critical opportunity to improve outcomes by acting on potential reversible factors, and also contribute to better understand this pathophysiologic enigma. In this review, we highlight major clinical contributors of PE and shed light about their potential link with endothelial dysfunction and inflammation.

Short tandem repeat near hypoxia response element (HRE) instead of HRE genetic variants in promoter calcitonin receptor-like receptor (CRLR) gene as risk factor in severe preeclampsia: a preliminary study

Objective

Calcitonin receptor-like receptor (CRLR) regulates vasoconstriction and dilatation; the expression increases during hypoxia via activation of hypoxia response element (HRE) in CRLR gene promoter region. Variant in HRE, as well short tandem repeat (STR) variants near HRE in CRLR alters the gene expression. This study focused on a case–control study to investigate the expression of genetic typing CLRL promoter variant in pregnant women with severe preeclampsia and normal pregnancies, we also tried to describe interesting findings of the genetic expression in anemic patients in the severe preeclampsia group. Our aimed to observe the correlation of CRLR gene promoter variant and anemia in severe preeclampsia.

Results

There was no nucleotide variant in HRE; CACA box prior to HRE varied in length (15–24); CACA box with length > 20 was used as cut off point. Hb was lower in CACA box length ≥ 21 (10.33 ± 1.57) vs. < 21 (11.01 ± 1.67; p = 0.391). CACA box polymorphism and anemia were correlated in severe preeclampsia (p = 0.005) OR 0.038 (CI 0.003–0.544); not in normal (p = 0.069).

Decidual memory T-cell subsets and memory T-cell stimulatory cytokines in early- and late-onset preeclampsia

PROBLEM

Preeclampsia is a major cause of fetal and maternal mortality and morbidity. Disturbed fetal-maternal immune tolerance, and therewith memory T cells, might be involved in its etiology. This study aims to give insight into memory T-cell populations and its associated cytokines in the decidual layers in early-onset preeclampsia (EO-PE) and late-onset preeclampsia (LO-PE).

METHOD OF STUDY

Lymphocytes were isolated from the decidua parietalis and basalis from EO-PE (n = 6), LO-PE (n = 8) and healthy (n = 15) pregnancies. CD4+ and CD8+ central- (CCR7+ ), effector- (CCR7- ), tissue resident- (CD103+ ), and regulatory- (Foxp3+ ) memory cell (CD45RO+ ) populations and their activation status (CD69+ ) were analyzed using flow cytometry. qRT-PCR analysis was performed on decidua parietalis and basalis biopsies to detect mRNA expression of interferon-gamma, interleukin-1B, IL2, IL6, IL7, IL8, IL10, IL15, and IL23.

RESULTS

CD4+ central-memory (CM) cell proportions were lower in the decidua parietalis in LO-PE (P < .0001) and EO-PE (P < .01) compared to healthy pregnancies. CD8+ memory (P < .05) and CD8+ CM (P < .01) cell proportions were also lower in the decidua parietalis in EO-PE compared to healthy pregnancies. This was accompanied by higher IL15 (P < .05) and IL23 (P < .05) and lower IL7 (P < .05) mRNA expression in decidua basalis biopsies from EO-PE compared to healthy pregnancies, analyzed by qPCR.

CONCLUSION

In conclusion, decidual memory T-cell proportions, their activation status, and associated cytokines are altered in preeclampsia and might therefore be involved in fetal-maternal immune tolerance and the pathophysiology of preeclampsia.

l-Tryptophan-Induced Vasodilation Is Enhanced in Preeclampsia: Studies on Its Uptake and Metabolism in the Human Placenta

l-tryptophan induces IDO (indoleamine 2,3-dioxygenase) 1-dependent vasodilation. IDO1 is expressed in placental endothelial cells and downregulated in preeclampsia. Hypothesizing that this may contribute to diminished placental perfusion, we studied l-tryptophan-induced vasodilation in healthy and early-onset preeclampsia placental arteries, focusing on placental kynurenine pathway alterations. Despite IDO1 downregulation, kynurenine pathway metabolite concentrations (measured with ultra-performance liquid chromatography-tandem mass spectrometry) were unaltered in preeclamptic versus healthy placentas. Most likely, this is due to enhanced l-tryptophan uptake, evidenced by increased l-tryptophan levels in preeclamptic placentas. Ex vivo perfused cotyledons from healthy and preeclamptic placentas released similar amounts of l-tryptophan and kynurenine pathway metabolites into the circulations. This release was not altered by adding l-tryptophan in the maternal circulation, suggesting that l-tryptophan metabolites act intracellularly. Maternally applied l-tryptophan did appear in the fetal circulation, confirming placental passage of this essential amino acid. After in vitro incubation of placental arteries with IDO1-upregulating cytokines interferon-γ and tumor necrosis factor-α, l-tryptophan induced vasodilation. This vasodilation was attenuated by both IDO1 and nitric oxide (NO) synthase inhibitors. Despite IDO1 downregulation, l-tryptophan-induced relaxation was enhanced in preeclamptic versus healthy placental arteries. However, cytokine stimulation additionally upregulated the LAT (l-type amino acid transporter) 1 in preeclamptic placental arteries only. Vasodilation to the lipophilic, transporter independent ethyl ester of l-tryptophan was reduced in preeclamptic versus healthy placental arteries, in agreement with reduced IDO1 expression. In conclusion, l-tryptophan induces IDO1- and NO-dependent relaxation in placental arteries, which is determined by l-tryptophan uptake rather than IDO1 expression. Increased l-tryptophan uptake might compensate for reduced IDO1 expression in preeclamptic placentas.

Validation of the 34-week gestation as definition of late onset preeclampsia: Testing different cutoffs from 30 to 37 weeks on a population-based cohort of 1700 preeclamptics

INTRODUCTION

Early onset preeclampsia (EOP) and late onset preeclampsia (LOP) have been differentiated with a cut-point of ≤34 weeks. This classical definition has never been examined with respect to maternal characteristics by different gestational age cut-points. We examined maternal characteristics in a population-based cohort of 1736 preeclamptic deliveries at different gestational age cut-points from 30 to 37 weeks (CO30 to CO37).

MATERIAL AND METHODS

Eighteen-year observational population-based historical cohort study (2001-2018). All consecutive births delivered at the Centre Hospitalier Universitaire Hospitalier Sud Reunion's maternity. Standardized epidemiological perinatal database.

RESULTS

The incidence of EOP was lower in adolescents (1.8% vs 3.5%, odds ratio [OR] 0.50, P = .17). Conversely, the odds of LOP was increased for women over 35, beginning at C030 (OR 1.13, P = .02) and this effect (OR = 1.2) was still detectable at C037 (P = .06). Among primigravid women, the incidence of EOP was lower than LOP (OR ranging from 0.71 to 0.82 for different CO). Conversely, the incidence of LOP was higher (adjusted OR about 2.7 [CO30-CO34] with a rise to 3.3 at CO37 (P < .001). Women with EOP had a lower body mass index (BMI) as compared with LOP at CO34 and CO37. The adjusted OR (per 5 kg/m² increment) declined from 1.06 to 1.03 from CO30 to C037 in EOP women. Conversely, for LOP, the adjusted odds ratio (aOR) increased from 1.04 to 1.06 from CO30 to CO37 (P < .001). Gestational diabetes mellitus was not associated with LOP at any cut-off (aOR 1.07, NS) but was protective against EOP from CO30 to CO34 (aOR 0.42, 0.61 and 0.73, respectively, P < .001). This protective effect disappeared at CO37. Chronic hypertension and history of preeclampsia were both EOP and LOP risks but with a much stronger effect for EOP (chronic hypertension: aOR 6.0-6.5, history of preeclampsia: aOR 12-17).

CONCLUSIONS

The 34th week of gestation appears to provide a reasonable cut-point to differentiate between EOP and LOP. Additional research is needed to better describe the possible differences in the pathophysiology of these different phenotypes.

Differences in DNA methylation of insulin-like growth factor 2 and cadherin 13 in patients with preeclampsia

OBJECTIVES

In a previous mass spectrometry study of our research group, 25 proteins were found to be differentially expressed in cerebrospinal fluid of patients with preeclampsia compared to controls. The objective of the current study was to investigate DNA methylation of the genes encoding for the former mentioned proteins in an independent dataset.

STUDY DESIGN

In a nested case-control study of the Rotterdam Periconceptional Cohort, placental tissue, umbilical cord white blood cells and human umbilical vein endothelial cells (HUVEC) were obtained of 13 patients with early-onset preeclampsia, 16 patients with late-onset preeclampsia and 83 normotensive controls (27 patients with fetal growth restriction, 20 patients with spontaneous preterm birth and 36 uncomplicated pregnancies). DNA methylation of 783 CpGs in regions of 25 genes was measured.

MAIN OUTCOME MEASURES

DNA methylation of selected candidate genes in early- and late-onset preeclampsia compared to fetal growth restriction, spontaneous preterm birth and uncomplicated controls.

RESULTS

From the 783 CpGs of the 25 selected genes, 15 CpGs were differentially methylated between early-onset preeclampsia and spontaneous preterm birth (3.80 E-5 ≤ p ≤ 0.036). Four CpGs were differentially methylated between early-onset preeclampsia and fetal growth restriction (0.0002 ≤ p ≤ 0.037) and 13 CpGs were differentially methylated between early onset preeclampsia and uncomplicated controls (0.0001 ≤ p ≤ 0.04).

CONCLUSION

Differences in DNA methylation were found in placental tissue, umbilical cord white blood cells and HUVEC of patients with early onset preeclampsia compared to (un)complicated controls, but not in patients with late-onset preeclampsia. The genes showing the largest differential methylation encode insulin-like growth factor 2 binding protein and receptor and cadherin 13.

RITA Is Expressed in Trophoblastic Cells and Is Involved in Differentiation Processes of the Placenta

Preeclampsia (PE) remains a leading cause of maternal and perinatal mortality and morbidity worldwide. Its pathogenesis has not been fully elucidated and no causal therapy is currently available. It is of clinical relevance to decipher novel molecular biomarkers. RITA (RBP-J (recombination signal binding protein J)-interacting and tubulin-associated protein) has been identified as a negative modulator of the Notch pathway and as a microtubule-associated protein important for cell migration and invasion. In the present work, we have systematically studied RITA’s expression in primary placental tissues from patients with early- and late-onset PE as well as in various trophoblastic cell lines. RITA is expressed in primary placental tissues throughout gestation, especially in proliferative villous cytotrophoblasts, in the terminally differentiated syncytiotrophoblast, and in migrating extravillous trophoblasts. RITA’s messenger RNA (mRNA) level is decreased in primary tissue samples from early-onset PE patients. The deficiency of RITA impairs the motility and invasion capacity of trophoblastic cell lines, and compromises the fusion ability of trophoblast-derived choriocarcinoma cells. These data suggest that RITA may play important roles in the development of the placenta and possibly in the pathogenesis of PE.

Increased BMI has a linear association with late-onset preeclampsia: A population-based study

Background

To investigate the ongoing controversy on the effect of BMI (body mass index) on EOP (early onset preeclampsia) vs LOP (late onset), especially focusing on diabetes and maternal booking/pre-pregnancy BMI as possible independent variables.

Methods

18 year-observational cohort study (2001–2018). The study population consisted of all consecutive births delivered at the Centre Hospitalier Universitaire Hospitalier Sud Reunion’s maternity (ap. 4,300 birth per year, only level 3 maternity in the south of Reunion Island, sole allowed to follow and deliver all preeclampsia cases of the area). History of pregnancies, deliveries and neonatal outcomes have been collected in standardized fashion into an epidemiological perinatal data base.

Results

Chronic hypertension and, history of preeclampsia in multigravidas, were the strongest risk factors for EOP. Primiparity, age over 35 years and BMI ≥ 35 kg/m² were rather associated with LOP. In a multivariate analysis with EOP or LOP as outcome variables compared with controls (normotensive), maternal age and pre-pregnancy BMI were independent risk factors for both EOP and LOP (p < 0.001). However, analyzing by increment of 5 (years of age, kg/m² for BMI) rising maternal ages and incidence of preeclampsia were strictly parallel for EOP and LOP, while increment of BMI was only associated with LOP. Controlling for maternal ages and booking/pre-pregnancy BMI, diabetes was not an independent risk factor neither for EOP or LOP.

Conclusions

Metabolic factors, other than diabetes, associated with pre-pregnancy maternal corpulence are specifically associated with LOP. This may be a direction for future researches on the maternal preeclamptic syndrome. This may explain the discrepancy we are facing nowadays where high-income countries report 90% of their preeclampsia being LOP, while it is only 60–70% in medium-low income countries.

Hemodynamic Allostasis of Pregnant Women against the Background of Preeclampsia

We analyzed diurnal hemodynamic parameters (HR, systolic BP, and diastolic BP) recorded from two groups of edematous and preeclamptic pregnant women. The unidirectional character of changes in the control over the functional state of cardiovascular system was revealed except for the indices, which mark a pathological process: elevated diurnal BP in preeclampsia and diminished percentage of oscillation power in edematous patients. Uniformity of the regulatory changes in patients with and without arterial hypertension can be viewed as manifestation of allostasis developed by the cardiovascular system during pregnancy. In preeclampsia, the greater allostatic load was reflected by the changes in diurnal, daytime, and nighttime BP and in the circadian index calculated for HR, systolic BP, and diastolic BP. In edematous patients, elevation of allostatic load was indicated by the percentage of ultradian rhythms.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.