The "Great Obstetrical Syndromes" are associated with disorders of deep placentation

Uterine NK cells: active regulators at the maternal-fetal interface

Pregnancy presents an immunological conundrum because two genetically different individuals coexist. The maternal lymphocytes at the uterine maternal-fetal interface that can recognize mismatched placental cells are T cells and abundant distinctive uterine NK (uNK) cells. Multiple mechanisms exist that avoid damaging T cell responses to the fetus, whereas activation of uNK cells is probably physiological. Indeed, genetic epidemiological data suggest that the variability of NK cell receptors and their MHC ligands define pregnancy success; however, exactly how uNK cells function in normal and pathological pregnancy is still unclear, and any therapies aimed at suppressing NK cells must be viewed with caution. Allorecognition of fetal placental cells by uNK cells is emerging as the key maternal-fetal immune mechanism that regulates placentation.

Concentrations of human chorionic gonadotrophin in very early pregnancy and subsequent pre-eclampsia: a cohort study

STUDY QUESTION

Are low serum concentrations of human chorionic gonadotrophin (hCG) in very early pregnancy associated with pre-eclampsia risk?

SUMMARY ANSWER

Low hCG concentrations in very early pregnancy are associated with increased risk of severe pre-eclampsia.

WHAT IS KNOWN ALREADY

Low maternal serum concentrations of hCG early in pregnancy may indicate impaired proliferation or invasion of trophoblast cells, and thus low hCG concentrations may serve as a marker for impaired placental development. Impaired placental development is assumed to be a cause of pre-eclampsia, but there is little prospective evidence to support this hypothesis.

STUDY DESIGN, SIZE, DURATION

We performed a prospective cohort study of pregnancies after IVF at Oslo University Hospital 1996-2010 with linkage to the Medical Birth Registry of Norway to obtain information on pre-eclampsia development.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included 2405 consecutive singleton pregnancies and examined the association of maternal serum hCG concentrations (measured using Elecsys, Roche) on Day 12 after embryo transfer with the risk of any pre-eclampsia and of mild and severe pre-eclampsia.

MAIN RESULTS AND THE ROLE OF CHANCE

HCG concentrations were inversely associated with pre-eclampsia risk in a dose-dependent manner (Ptrend 0.02). Compared with women with hCG ≥150 IU/l, women with hCG <50 IU/l were at 2-fold higher overall risk of pre-eclampsia [absolute risk 6.4 versus 2.8%; odds ratio (OR) 2.3, 95% confidence interval (CI) 1.2-4.7]. The inverse association was restricted to severe pre-eclampsia (Ptrend 0.01), thus, women with hCG <50 IU/l were at 4-fold higher risk of severe pre-eclampsia than women with hCG ≥150 IU/l (absolute risk 3.6 versus 0.9%; OR 4.2, 95% CI 1.4-12.2). For mild pre-eclampsia, there was no corresponding association (Ptrend 0.36).

LIMITATIONS, REASONS FOR CAUTION

Results for IVF pregnancies may not be generalizable to spontaneously conceived pregnancies.

WIDER IMPLICATIONS OF THE FINDINGS

Plausible causes of low maternal hCG concentrations very early in pregnancy include impaired placental development and delayed implantation. Thus, these results provide prospective evidence to support the hypothesis that impaired placental development may be associated with subsequent development of severe pre-eclampsia.

STUDY FUNDING/COMPETING INTEREST

The study was financially supported by the Research Council of Norway. None of the authors has any conflict of interest to declare.

Epidemiology of ischemic placental disease: a focus on preterm gestations

Preeclampsia, placental abruption, and intrauterine growth restriction (IUGR) have collectively been termed ischemic placental disease (IPD) due to a suspected common biological pathway involving poor placentation in early pregnancy and subsequent placental insufficiency. Despite decades of research, the etiologies of these conditions remain largely unknown and preventive and therapeutic strategies are lacking. It has been suggested that the underpinnings of IPD lie primarily in preterm gestations and that classification of these conditions based on the gestational age at onset will facilitate etiologic research. The purpose of this review is to describe our current knowledge regarding the risk factors, co-occurrence, and recurrence of the conditions of IPD with a specific focus on the preterm gestational window.

First trimester prediction of ischemic placental disease

Ischemic placental disease is characterized by one or more of the clinical manifestations of preeclampsia, fetal growth restriction, and/or placental abruption, resulting in indicated preterm delivery. Since over half of the indicated preterm deliveries are due to ischemic placental disease, accurate early prediction of the disease is of paramount importance in developing prevention strategies. This review article focuses on studies that have used the first trimester aneuploidy screening timing window to predict those patients who later develop ischemic placental disease. Emphasis was given to studies originating from the Fetal Medicine Foundation because of their uniformity in definitions and expertise of the personnel who performed the ultrasound screening exams.

[Adverse pregnancy outcomes after Assisted Reproduction Technology in women with endometriosis]

OBJECTIVE

While association between endometriosis and infertility is well established, there are few studies about the impact of endometriosis on adverse pregnancy outcomes. The aim of this study was to determine the effect of endometriosis on obstetric outcomes and whether the severity of the disease had an influence on these.

PATIENTS AND METHODS

We performed a retrospective study to investigate the obstetric outcomes of a population of 1204 subfertile women, including 258 with endometriosis, who obtained, thanks to assisted reproduction technology, a singleton pregnancy evolving beyond embryonic stage. Two analyzes were performed. The first compared women with endometriosis to women with other causes of infertility. The second observed adverse pregnancy outcomes according to AFS-R stages of endometriosis.

RESULTS

The overall rate of live birth children was 95.8%. In case of endometriosis, there was a significant increase of the incidence of preterm delivery, especially before 32 weeks amenorrhea (6.2% vs 3.1% in the group "without endometriosis", P = 0.03), antenatal bleeding (5.3% vs 2.2%, P = 0.01) and placenta previa (4.9% vs 0.9%, P < 0.0001). The incidence of gestational diabetes was significantly decreased (0.4% vs 2.7%, P = 0.04). There was no correlation between endometriosis and cesarean section or preeclampsia, or between the AFS-R stage and adverse pregnancy outcomes.

DISCUSSION AND CONCLUSION

Endometriosis is a factor of obstetrical risk, independently of the infertility it causes. The AFS-R score does not seem to be representative of obstetric outcomes beyond first trimester of pregnancy for women with endometriosis.

Comparison of placental pathology in preterm, late-preterm, near-term, and term births

OBJECTIVE

The purpose of this study was to determine whether placental pathologic condition supports the recent suggestion of subcategorizing preterm and term births into smaller gestational age subgroups with different perinatal mortality and morbidity rates.

STUDY DESIGN

Twenty-seven clinical and 43 placental phenotypes were retrospectively compared in 4617 third-trimester births: 1332 preterm pregnancies (28-33 weeks' gestation), 1066 late preterm pregnancies (34-36 weeks' gestation), 940 near-term pregnancies (37-38 weeks' gestation), and 1279 term pregnancies (≥39 weeks' gestation).

RESULTS

Acute inflammatory pattern of placental injury was seen mostly at both gestational sides of the third trimester; the clinical conditions linked to in utero hypoxia (preeclampsia, diabetes mellitus, fetal growth restriction) and their placental associations (atherosis, membrane chorionic microcysts, chorangiosis, intervillous thrombi) were associated statistically significantly with mid third trimester. Acute fetal distress (abnormal fetal heart tracing and clinical and histologic meconium) were increasing with gestational age and were statistically significantly most common in full-term pregnancies.

CONCLUSION

Differences in placental pathologic condition among the 4 subgroups of third-trimester pregnancy not only challenge the use of an arbitrary cutoff point of 37 weeks' gestation that separates the preterm birth and term birth but also further support separation of late preterm births from preterm births and term births from near-term births. Based on placental pathologic condition, chronic uteroplacental malperfusion is the dominating etiopathogenetic factor in the mid third trimester (late preterm and near-term births), and acute fetal distress is the factor in full-term births. This obscures relative frequencies of perinatal death and management modalities in the third trimester.

A pilot study to determine whether progestogen supplementation using dydrogesterone during the first trimester will reduce the incidence of gestational hypertension in primigravidae

BACKGROUND

Gestational hypertension (GH) remains one of the main causes of high maternal and perinatal morbidity and mortality worldwide with the highest incidence among primigravidae of about 10%-15%. However, it was noted that the incidence of GH in primigravidae who conceived following assisted reproductive technique (ART) or intrauterine insemination (IUI) supplemented with dydrogesterone during the first trimester was low.

AIM

To determine whether dydrogesterone supplementation during the first trimester can reduce the incidence of GH among primigravidae.

METHOD

A prospective cross-sectional comparative study was undertaken in 2010 on 116 primigravidae (study group) who conceived following ART or IUI and supplemented with dydrogesterone up to 16 weeks gestation. They were matched for age and race at 16 weeks gestation with a control patient from the early pregnancy clinic who were primigravidae (n = 116) who conceived spontaneously without dydrogesterone supplementation.

FINDINGS

The incidence of GH in the study group was significantly lower than the control group (1.7% versus 12.9%, p = 0.001). The incidence of fetal distress was also significantly lower in the study group compared to the control group (4.3% versus 18.1%, p = 0.001).

INTERPRETATION

Dydrogesterone supplementation during the first trimester significantly reduced the incidence of GH and fetal distress in primigravidae.

Uterine artery impedance at very early clinical pregnancy

OBJECTIVE

The aim of the study was to construct gestational age-based reference ranges for the uterine artery (UtA) mean pulsatility (PI) and resistance (RI) indices from 6 to 10 weeks of pregnancy.

METHOD

A prospective, cross-sectional, observational study was carried out in 312 singleton pregnancies with gestational age ranging from 6 to 10 weeks. UtAs were examined transvaginally by color and pulsed Doppler imaging, and the mean of the right and left values of PI and RI, as well as the presence or absence of a bilateral protodiastolic notch, was recorded. UtA-PI and UtA-RI reference percentiles were derived through time-conditional quantile regression.

RESULTS

The authors derived the 10th, 50th, and 90th reference percentile curves and correspondent 95% confidence intervals, for the evolution of the UtA mean PI and RI from week 6 to week 10 of gestation. The prevalence of bilateral notching absence was 8.1% (6/74) at 6 weeks and 28.8% (15/52) at 10 weeks.

CONCLUSION

The authors present evidence of progressive reduction of uterine vascular impedance in a very early stage of pregnancy and provide new, averaged UtA-PI and UtA-RI charts between 6 and 10 weeks of gestation.

Internal iliac and uterine arteries Doppler ultrasound in the assessment of normotensive and chronic hypertensive pregnant women

The objective of this work was to compare Doppler flows pulsatility index (PI) and resistance indexes (RI) of uterine and internal iliac arteries during pregnancy in low risk women and in those with stage-1 essential hypertension. From January 2010 and December 2012, a longitudinal and prospective study was carried out in 103 singleton uneventful pregnancies (72 low-risk pregnancies and 31 with stage 1 essential hypertension)at the 1^st, 2^nd and 3^rd trimesters. Multiple linear regression models, fitted using generalized least squares and whose errors were allowed to be correlated and/or have unequal variances, were employed; a model for the relative differences of both arteries impedance was utilized. In both groups, uterine artery PI and RI exhibited a gestational age related decreasing trend whereas internal iliac artery PI and RI increased. The model testing the hemodynamic adaptation in women with and without hypertension showed similar trend. Irrespective of blood pressure conditions, the internal iliac artery resistance pattern contrasts with the capacitance pattern of its immediate pelvic division, suggesting a pregnancy-related regulatory mechanism in the pelvic circulation.

Influence of speed of sample processing on placental energetics and signalling pathways: implications for tissue collection

Introduction

The placenta is metabolically highly active due to extensive endocrine and active transport functions. Hence, placental tissues soon become ischaemic after separation from the maternal blood supply. Ischaemia rapidly depletes intracellular ATP, and leads to activation of stress-response pathways aimed at reducing metabolic demands and conserving energy resources for vital functions. Therefore, this study aimed to elucidate the effects of ischaemia ex vivo as may occur during tissue collection on phosphorylation of placental proteins and kinases involved in growth and cell survival, and on mitochondrial complexes.

Methods

Eight term placentas obtained from normotensive non-laboured elective caesarean sections were kept at room-temperature and sampled at 10, 20, 30 and 45 min after delivery. Samples were analyzed by Western blotting.

Results

Between 10 and 45 min the survival signalling pathway intermediates, P-AKT, P-GSK3α and β, P-4E-BP1 and P-p70S6K were reduced by 30–65%. Stress signalling intermediates, P-eIF2α increased almost 3 fold after 45 min. However, other endoplasmic reticulum stress markers and the Heat Shock Proteins, HSP27, HSP70 and HSP90, did not change. Phosphorylation of AMPK, an energy sensor, was elevated 2 fold after 45 min. Contemporaneously, there was an ∼25% reduction in mitochondrial complex IV subunit I.

Discussion and conclusions

These results suggest that for placental signalling studies, samples should be taken and processed within 10 min of caesarean delivery to minimize the impact of ischaemia on protein phosphorylation.

Punicalagin, a polyphenol in pomegranate juice, downregulates p53 and attenuates hypoxia-induced apoptosis in cultured human placental syncytiotrophoblasts

Oxidative stress is associated with placental dysfunction and suboptimal pregnancy outcomes. Therapeutic interventions to limit placental injury from oxidative stress are lacking. Punicalagin is an ellagitannin and a potent antioxidant in pomegranate juice. We showed that both pomegranate juice and punicalagin decrease oxidative stress and apoptosis in cultured syncytiotrophoblasts. p53 is involved in the oxidative stress-induced apoptosis in trophoblasts. We now test the hypothesis that punicalagin limits trophoblast injury in vitro by regulating the levels of p53. We examined the expression of p53, mouse double minute 2 homolog, p21, hypoxia-inducible factor (HIF) α, and selected members of the B cell lymphoma 2 (BCL2) family of proteins in cultured syncytiotrophoblasts exposed to ≤1% oxygen in the absence or presence of punicalagin. We found that punicalagin attenuated hypoxia-induced apoptosis in syncytiotrophoblasts, as quantified by levels of cleaved poly-ADP ribose polymerase. This protective effect was in part mediated by reduced p53 activity shown by decreased expression of p21, lower HIF1α expression, and limited activity of caspases 9 and 3. There was no change in expression of proteins in the BCL2 family, which are also important in apoptosis. The data support a role for downregulation of p53 in the protection of human trophoblasts by punicalagin.

Peripheral insertion of umbilical cord

Numerous studies have addressed the significance of marginal and membranous umbilical cord (UC) insertion. Recent reports suggest that an eccentrically inserted UC may also be important. This case-control study assessed the potential relevance of peripheral insertion of UC (PIUC), defined as <3 cm from the nearest margin. Singleton placentas (n  =  1418) submitted to the pathology department over an 18-month period were analyzed. Each case of PIUC (n  =  119) was matched with a control placenta of the same gestational age. Placentas with marginal or membranous UC and multiple gestations were excluded. The overall prevalence of PIUC was 8.4%, but PIUC frequency was significantly increased in premature births at <28 weeks (21.4%, P < 0.001). There was no association with other adverse pregnancy outcomes. PIUC was associated with decreased placental weight Z-score (-0.69 ± 0.92 versus -0.22 ± 1.3, P  =  0.0056), but not fetal weight Z-score, suggesting increased utilization of placental reserve. PIUC was also associated with relatively elongated placentas (length minus width: 2.6 ± 3.2 versus 1.0 ± 3.1, P  =  0.006). PIUC tended to be more frequent in young primiparous mothers and was significantly less common in women with a history of prior curettage (66% vs 50%, P  =  0.013). These data, together with equivalent rates of prior cesarean section, multiparity, and advanced maternal age, support a primary developmental disorder as opposed to secondary placental migration due to underlying uterine abnormalities ("trophotropism"). Except for a borderline significant association with findings suggestive of maternal malperfusion (P  =  0.078), PIUC was not associated with other placental lesions.

AGEs, contributors to placental bed vascular changes leading to preeclampsia

Glycation of proteins or other biomolecules and their further long-term degradation result in the formation of advanced glycation end products, AGEs. AGEs and other ligands interact with their receptors, RAGEs, localized to a variety of tissues, but mainly in endothelium and vascular wall cells. This interaction triggers diverse signaling pathways that converge on the activation of NF-κB and the initiation of a local inflammatory reaction that, when prolonged, results in dysfunctional features. Preeclampsia is a serious vascular disorder centred at the placenta-uterine interface, the placental bed, but the condition extends to the mother's circulation. RAGEs have notorious expression in the placental bed tissues along pregnancy but, in addition, RAGEs and their ligands are expressed in the fetal membranes and are found in the amniotic fluid and the mother's serum. Disorders complicating pregnancies and having an important vascular involvement, as preeclampsia and diabetes mellitus, have additional enhanced AGE/RAGE expression variation. This indicates that for their assessment, the assay of RAGEs or their ligands may become useful diagnostic or prognostic procedures.

Transforming growth factor-β1 inhibits trophoblast cell invasion by inducing Snail-mediated down-regulation of vascular endothelial-cadherin protein

Human trophoblast cells express transforming growth factor-β (TGF-β) and TGF-β receptors. It has been shown that TGF-β1 treatment decreases the invasiveness of trophoblast cells. However, the molecular mechanisms underlying TGF-β1-decreased trophoblast invasion are still not fully understood. In the current study, we demonstrated that treatment of HTR-8/SVneo human trophoblast cells with TGF-β1 decreased cell invasion and down-regulated the expression of vascular endothelial cadherin (VE-cadherin). In addition, the inhibitory effect of TGF-β1 on VE-cadherin was confirmed in primary cultures of human trophoblast cells. Moreover, knockdown of VE-cadherin using siRNA decreased the invasiveness of HTR-8/SVneo cells and primary cultures of trophoblast cells. Treatment with TGF-β1 induced the activation of Smad-dependent signaling pathways and the expression of Snail and Slug. Knockdown of Smads attenuated TGF-β1-induced up-regulation of Snail and Slug and down-regulation of VE-cadherin. Interestingly, depletion of Snail, but not Slug, attenuated TGF-β1-induced down-regulation of VE-cadherin. Furthermore, overexpression of Snail suppressed VE-cadherin expression. Chromatin immunoprecipitation analyses showed the direct binding of Snail to the VE-cadherin promoter. These results provide evidence that Snail mediates TGF-β1-induced down-regulation of VE-cadherin, which subsequently contributed to TGF-β1-decreased trophoblast cell invasion.

Endometriosis: a life cycle approach?

To improve the still fragmented understanding of endometriosis, a life cycle approach was adopted that revealed unexpected aspects of the natural history of the disease throughout a woman's life. Three age-related stages of endometriosis are distinguished. In premenarcheal and adolescent endometriosis, 2 types can be distinguished: a classic form that can occur before menarche, and a congenital obstructive form that is caused by uterine anomaly and outflow obstruction. The lesions include superficial peritoneal implants, but adhesions and endometrioma can also occur. It is suggested that premenarcheal and possibly adolescent endometriosis develop by activation of resting stem cells shed at the time of neonatal retrograde uterine bleeding. In the adult, endometriosis can be related to uterine preconditioning by cyclic menstruations acting as a priming mechanism for deep placentation. In adult life, the typical lesions are peritoneal, ovarian, and deep or adenomyotic endometriosis. More recently, endometriosis has been associated with endometrial dysfunction and myometrial junctional zone hyperplasia. These uterine changes can be linked with some major obstetrical syndromes. In postmenopause, endometriosis can develop or be reactivated both in the presence or absence of exogenous estrogens and can spread to a variety of organs and structures causing constrictive lesions.

Maternal uterine NK cell-activating receptor KIR2DS1 enhances placentation

Reduced trophoblast invasion and vascular conversion in decidua are thought to be the primary defect of common pregnancy disorders including preeclampsia and fetal growth restriction. Genetic studies suggest these conditions are linked to combinations of polymorphic killer cell Ig-like receptor (KIR) genes expressed by maternal decidual NK cells (dNK) and HLA-C genes expressed by fetal trophoblast. Inhibitory KIR2DL1 and activating KIR2DS1 both bind HLA-C2, but confer increased risk or protection from pregnancy disorders, respectively. The mechanisms underlying these genetic associations with opposing outcomes are unknown. We show that KIR2DS1 is highly expressed in dNK, stimulating strong activation of KIR2DS1+ dNK. We used microarrays to identify additional responses triggered by binding of KIR2DS1 or KIR2DL1 to HLA-C2 and found different responses in dNK coexpressing KIR2DS1 with KIR2DL1 compared with dNK only expressing KIR2DL1. Activation of KIR2DS1+ dNK by HLA-C2 stimulated production of soluble products including GM-CSF, detected by intracellular FACS and ELISA. We demonstrated that GM-CSF enhanced migration of primary trophoblast and JEG-3 trophoblast cells in vitro. These findings provide a molecular mechanism explaining how recognition of HLA class I molecules on fetal trophoblast by an activating KIR on maternal dNK may be beneficial for placentation.

Differences and similarities in the transcriptional profile of peripheral whole blood in early and late-onset preeclampsia: insights into the molecular basis of the phenotype of preeclampsiaa

OBJECTIVE

Preeclampsia (PE) can be sub-divided into early- and late-onset phenotypes. The pathogenesis of these two phenotypes has not been elucidated. To gain insight into the mechanisms of disease, the transcriptional profiles of whole blood from women with early- and late-onset PE were examined.

METHODS

A cross-sectional study was conducted to include women with: i) early-onset PE (diagnosed prior to 34 weeks, n=25); ii) late-onset PE (after 34 weeks, n=47); and iii) uncomplicated pregnancy (n=61). Microarray analysis of mRNA expression in peripheral whole blood was undertaken using Affymetrix microarrays. Differential gene expression was evaluated using a moderated t-test (false discovery rate <0.1 and fold change >1.5), adjusting for maternal white blood cell count and gestational age. Validation by real-time qRT-PCR was performed in a larger sample size [early PE (n=31), late PE (n=72) and controls (n=99)] in all differentially expressed genes. Gene ontology analysis and pathway analysis were performed.

RESULTS

i) 43 and 28 genes were differentially expressed in early- and late-onset PE compared to the control group, respectively; ii) qRT-PCR confirmed the microarray results for early and late-onset PE in 77% (33/43) and 71% (20/28) of genes, respectively; iii) 20 genes that are involved in coagulation (SERPINI2), immune regulation (VSIG4, CD24), developmental process (H19) and inflammation (S100A10) were differentially expressed in early-onset PE alone. In contrast, only seven genes that encoded proteins involved in innate immunity (LTF, ELANE) and cell-to-cell recognition in the nervous system (CNTNAP3) were differentially expressed in late-onset PE alone. Thirteen genes that encode proteins involved in host defense (DEFA4, BPI, CTSG, LCN2), tight junctions in blood-brain barrier (EMP1) and liver regeneration (ECT2) were differentially expressed in both early- and late-onset PE.

CONCLUSION

Early- and late-onset PE are characterized by a common signature in the transcriptional profile of whole blood. A small set of genes were differentially regulated in early- and late-onset PE. Future studies of the biological function, expression timetable and protein expression of these genes may provide insight into the pathophysiology of PE.

The anti-aging factor α-klotho during human pregnancy and its expression in pregnancies complicated by small-for-gestational-age neonates and/or preeclampsia

OBJECTIVE

α-klotho, a protein with anti-aging properties, has been involved in important biological processes, such as calcium/phosphate metabolism, resistance to oxidative stress, and nitric oxide production in the endothelium. Recent studies have suggested a role of α-klotho in endocrine regulation of mineral metabolism and postnatal growth in infants. Yet, the role of α-klotho during pregnancy remains largely unknown. The aim of this study was to determine whether maternal plasma concentration of α-klotho changes during pregnancy and evaluate its expression in pregnancies complicated by small for gestational age (SGA) and/or preeclampsia (PE).

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) non pregnant women (n = 37); (2) uncomplicated pregnancy (n = 130); (3) PE without an SGA neonate (PE; n = 58); (4) PE with an SGA neonate (PE and SGA; n = 52); and (5) SGA neonate without PE (SGA; n = 52). Plasma concentrations of α-klotho were determined by ELISA.

RESULTS

The median plasma α-klotho concentration was higher in pregnant than in non-pregnant women. Among women with an uncomplicated pregnancy, the median plasma concentration of α-klotho increased as a function of gestational age (Spearman Rho = 0.2; p = 0.006). The median (interquartile range) plasma concentration of α-klotho in women with PE and SGA [947.6 (762-2013) pg/mL] and SGA without PE [1000 (585-1567) pg/mL] were 21% and 17% lower than that observed in women with an uncomplicated pregnancy [1206.6 (894-2012) pg/mL], (p = 0.005 and p = 0.02), respectively. Additionally, there were no significant differences in the median plasma concentration of α-klotho between uncomplicated pregnancies and women with PE without an SGA neonate (p = 0.5).

CONCLUSION

Maternal plasma concentration of α-klotho was higher during pregnancy than in a non-pregnant state. Moreover, the median maternal plasma concentration of α-klotho was lower in mothers who delivered an SGA neonate than in those with an uncomplicated pregnancy regardless of the presence or absence of PE.

Maternal plasma soluble TRAIL is decreased in preeclampsia

OBJECTIVE

Preeclampsia (PE) is characterized by systemic intravascular inflammation. Women who develop PE are at an increased risk for cardiovascular disease in later life. Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) has anti-atherosclerotic effects in endothelial cells and can mediate neutrophil apoptosis. Low soluble TRAIL (sTRAIL) and high C-reactive protein (CRP) concentrations are associated with an increased risk of future cardiovascular disease in non-pregnant individuals. The aim of this study was to determine whether maternal plasma concentrations of sTRAIL and CRP differ between women with PE and those with uncomplicated pregnancies.

METHOD

This cross-sectional study included women with an uncomplicated pregnancy (n = 93) and those with PE (n = 52). Maternal plasma concentrations of sTRAIL and CRP concentrations were determined by ELISA.

RESULTS

1) The median plasma sTRAIL concentration (pg/mL) was significantly lower and the median plasma CRP concentration was significantly higher in women with PE than in those with an uncomplicated pregnancy (25.55 versus 29.17; p = 0.03 and 8.0 versus 4.1; p = 0.001, respectively); 2) the median plasma concentration sTRAIL/CRP ratio was two-fold lower in women with PE than in those with an uncomplicated pregnancy (p < 0.001); and 3) women with plasma sTRAIL and CRP ratio in the lowest quartile were 8 times more likely to have PE than women with concentrations in the upper three quartiles (OR 8.9; 95% CI: 2.8-27.8).

CONCLUSION

Maternal plasma sTRAIL concentrations are lower (while those of CRP are higher) in women with PE than in those with uncomplicated pregnancies. These findings are consistent with the evidence of intravascular inflammation in this disorder.

Plasma concentrations of angiogenic/anti-angiogenic factors have prognostic value in women presenting with suspected preeclampsia to the obstetrical triage area: a prospective study

OBJECTIVE

To prospectively determine the prognostic value of maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng) and soluble vascular endothelial growth factor receptors-1 and -2 (sVEGFR-1 and -2) in identifying patients with suspected preeclampsia (PE), who require preterm delivery (PTD) or develop adverse outcomes.

STUDY DESIGN

This prospective cohort study included 85 consecutive patients who presented to the obstetrical triage area at 20-36 weeks with a diagnosis of "rule out PE." Patients were classified as: 1) those who remained stable until term (n = 37); and 2) those who developed severe PE and required PTD (n = 48). Plasma concentrations of PlGF, sEng and sVEGFR-1 and -2 were determined by ELISA.

RESULTS

Patients with PlGF/sVEGFR-1 ≤0.05 multiples of the median (MoM) or PlGF/sEng ≤0.07 MoM were more likely to deliver preterm due to PE [adjusted odd ratio (aOR) 7.4 and 8.8], and to develop maternal (aOR 3.7 and 2.4) or neonatal complications (aOR 10.0 and 10.1). Among patients who presented <34 weeks of gestation, PlGF/sVEGFR-1 ≤ 0.035 MoM or PlGF/sEng ≤0.05 MoM had a sensitivity of 89% (16/18), specificity of 96% (24/25) and likelihood ratio for a positive test of 22 to identify patients who delivered within 2 weeks. The addition of the PlGF/sVEGFR-1 ratio to standard clinical tests improved the sensitivity at a fixed false-positive rate of 3% (p = 0.004) for the identification of patients who were delivered due to PE within 2 weeks. Among patients who had a plasma concentration of PlGF/sVEGFR-1 ratio ≤0.035 MoM, 0.036-0.34 MoM and ≥0.35 MoM, the rates of PTD <34 weeks were 94%, 27% and 7%, respectively.

CONCLUSIONS

The determination of angiogenic/anti-angiogenic factors has prognostic value in patients presenting to the obstetrical triage area with suspected PE for the identification of those requiring preterm delivery and at risk for adverse maternal/neonatal outcomes.

Circulating RNA coding genes regulating apoptosis in maternal blood in severe early onset fetal growth restriction and pre-eclampsia

OBJECTIVE

To determine whether the intrinsic apoptosis pathway is differentially expressed in placenta and maternal blood in severe preterm fetal growth restriction (FGR) and pre-eclampsia (PE), and to examine whether circulating RNA in maternal blood may be potential biomarkers.

STUDY DESIGN

Maternal blood samples and placental biopsies were collected from women with preterm: FGR (n=20), PE without FGR (n=8) and controls (n=20). Real-time PCR examined the expression of genes in the intrinsic apoptosis pathway in FGR and PE, stratified according to the severity of placental insufficiency.

RESULT

Severe preterm FGR, with or without PE, was associated with increased expression of BCL2, BCL-XL, BIM, BAD and Survivin in both the placenta and maternal blood (1.6 to 3.3-fold, P<0.05). In preterm PE, but not FGR, there was increased placental expression of BCL-XL and BCL2 (1.6 to 2.5-fold, P<0.05), but only BCL2 was significantly increased in the maternal blood (1.8-fold, P<0.05). Increased expression of genes of the intrinsic apoptosis pathway reflected the severity of FGR as determined by deteriorations in umbilical artery Doppler velocimetry.

CONCLUSION

In severe early onset FGR there was increased expression of genes regulating intrinsic apoptosis in both the placenta and maternal blood. Circulating RNA regulating placenta apoptosis may be used to develop noninvasive novel biomarkers for FGR.

Heme oxygenase in pregnancy and preeclampsia

PURPOSE OF REVIEW

Emerging evidence supports an important role for the heme oxygenase system in the maintenance of a healthy pregnancy. This review attempts to collect these wide-ranging data and summarize the recent progress in the field.

RECENT FINDINGS

New studies looking at heme oxygenase depletion in a variety of animal models have demonstrated that the heme oxygenase system is an important regulator of placental development, particularly in vascular structure. Furthermore, emerging studies demonstrate a role for heme oxygenase in the maintenance of pregnancy, especially during pathological challenge. Intriguingly, it now appears that the heme oxygenase system can be dramatically altered by pathological disorders of pregnancy, in particular preeclampsia, perhaps functionally in the symptomatic phase of the disorder. Promisingly, however, recent data suggest that induction of the heme oxygenase system, or administration of its bioactive metabolites, could provide a promising novel therapeutic approach to the management of this currently untreatable disease.

SUMMARY

Long considered a molecular housekeeping system, the heme oxygenase system is now known to be an important stress response pathway. New evidence suggests that it is also an important player in pregnancy and preeclampsia. However, the evidence now also suggests that it may provide a therapeutic approach for this common disease with few management options.

If we know so much about preeclampsia, why haven't we cured the disease?

Preeclampsia has been recognized for at least 100 years. In the last 20 years, the consideration of the disorder as more than simply hypertension in pregnancy has led to an explosion in knowledge about preeclampsia pathophysiology. It is now evident that for most cases of preeclampsia, the root cause is the placenta. Relatively reduced placental perfusion leads to inflammation, oxidative stress, and endoplasmic reticulum stress, which converge to modify maternal physiology, with endothelium an important target. Although preeclampsia is characteristically diagnosed in the last third of pregnancy, it is evident that many of these pathophysiological changes can be detected long before clinically evident disease. Furthermore, it is evident that the "maternal constitution," including genetic, behavioral, and metabolic factors, influences the maternal response to the abnormal placentation of preeclampsia. These insights would seem to provide a guide for the prediction of the disorder in early pregnancy, along with targets for intervention. However, this has not been the case. Predictive tests guided by this knowledge do not predict well and several interventions guided by the expanded understanding of pathophysiology do not prevent the disease. We propose that these failures are secondary to the fact that preeclampsia is more than one disorder. Further, we suggest that future progress toward prediction and prevention will require research guided by this concept.

Preeclampsia: a link between trophoblast dysregulation and an antiangiogenic state

A 24-year-old nulliparous woman developed mildly elevated blood pressure (140-150/90-100 mmHg) without proteinuria (20 mg protein in a 24-hour urine collection) at 30⁶/⁷ weeks of gestation. The fetus was small for gestational age (estimated fetal weight under the fifth percentile). At 32⁵/⁷ weeks of gestation, the patient complained of epigastric pain, blood pressure was 180/110 mmHg, proteinuria was documented (780 mg protein in a 24-hour urine collection), schistocytes were detected in the peripheral smear, platelet count was 60,000 cells per mm³, and serum glutamic oxaloacetic transaminase was 234 U/l. The patient was diagnosed with severe preeclampsia/HELLP syndrome. Antenatal steroids were administered to induce fetal lung maturity. She and her family want to know the causes of this condition, what treatment is available, and whether there are any long-term implications of this diagnosis.

Maternal plasma concentrations of sST2 and angiogenic/anti-angiogenic factors in preeclampsia

OBJECTIVES

Angiogenic/anti-angiogenic factors have emerged as one of the promising biomarkers for the prediction of preeclampsia. Since not all patients with preeclampsia can be identified by these analytes, the search for additional biomarkers continues. The soluble form of ST2 (sST2), a protein capable of binding to interleukin (IL)-33 and thus contributing to a Th1-biased immune response, has been reported to be elevated in maternal plasma of women with preeclampsia. The aims of this study were to examine: (1) differences in maternal plasma concentrations of sST2 and IL-33 between women diagnosed with preeclampsia and those having uncomplicated pregnancies; (2) the relationship between sST2, umbilical and uterine artery Doppler velocimetry, and the severity of preeclampsia; and (3) the performance of sST2 and angiogenic/anti-angiogenic factors in identifying patients with preeclampsia at the time of diagnosis.

METHODS

This cross-sectional study included women with preeclampsia (n = 106) and women with an uncomplicated pregnancy (n = 131). Plasma concentrations of sST2, IL-33, soluble vascular endothelial growth factor receptor (sVEGFR)-1, soluble endoglin (sEng) and placental growth factor (PlGF) were determined by enzyme linked immune sorbent assay. Area under the receiver operating characteristic curve (AUC) for the identification of preeclampsia was examined for each analyte.

RESULTS

(1) Patients with preeclampsia had a higher mean plasma concentrations of sST2 than those with an uncomplicated pregnancy (p < 0.0001), while no significant difference in the mean plasma concentration of IL-33 between the two groups was observed; (2) the magnitude of this difference was greater in early-onset, compared to late-onset disease, and in severe compared to mild preeclampsia; (3) sST2 plasma concentrations did not correlate with the results of uterine or umbilical artery Doppler velocimetry (p = 0.7 and p = 1, respectively) among women with preeclampsia; (4) sST2 correlated positively with plasma concentrations of sVEGFR1-1 and sEng (Spearman's Rho = 0.72 and 0.63; each p < 0.0001), and negatively with PlGF (Spearman's Rho = -0.56, p < 0.0001); and (5) while the AUC achieved by sST2 and angiogenic/anti-angiogenic factors in identifying women with preeclampsia at the time of diagnosis were non-significantly different prior to term (<37 weeks of gestation), thereafter the AUC achieved by sST2 was significantly less than that achieved by angiogenic/anti-angiogenic factors.

CONCLUSIONS

Preeclampsia is associated with increased maternal plasma concentrations of sST2. The findings that sST2 concentrations do not correlate with uterine or umbilical artery Doppler velocimetry in women with preeclampsia suggest that elevated maternal plasma sST2 concentrations in preeclampsia are not related to the increased impedance to flow in the utero-placental circulation. The performance of sST2 in identifying preeclampsia at the time of diagnosis prior to 37 weeks of gestation was comparable to that of angiogenic/anti-angiogenic factors. It remains to be elucidated if an elevation of maternal plasma sST2 concentrations in pregnancy is specific to preeclampsia.

Abruptio placentae in cynomolgus macaques (Macaca fascicularis): male bias

BACKGROUND

Abruptio placentae is a serious problem with a high rate of maternal and fetal mortality and documented sexual dimorphism in reoccurrence. Macaca fascicularis is a well-described reproductive model; however, there are no data available regarding sexual dimorphism in abruptio placentae in these species.

METHODS

A retrospective study of pathology and medical records in a large colony of M. fascicularis was performed. Placental specimens were analyzed.

RESULTS

The incidence of placenta abruptio in the colony was 15.7/1000 births. In the abruptio placentae group, male fetuses had lower placental disk length and increased femur length compared with female fetuses. The feto-pacental ratio and fetal weight were lower in the male fetuses in the abruption group compared with those in the stillbirth group without abruption placentae.

CONCLUSION

This is the first documentation of male bias in placental and fetal development in abruptio placentae in non-human primates.

Association between first trimester vaginal bleeding and uterine artery Doppler measured at second and third trimesters of pregnancy

OBJECTIVE

To evaluate the prevalence of first trimester vaginal bleeding among patients with abnormal second and third trimester uterine artery Doppler.

METHODS

A prospective study of patients with a uterine artery Doppler measurement between 27 and 42 weeks' gestation was undertaken. A comparison was made between two groups: patients with and without first trimester vaginal bleeding. Abnormal uterine artery Doppler was defined as PI >95th% or the presence of a diastolic notch.

RESULTS

Of the 277 patients that were included in the study, 65 (23%) had first trimester vaginal bleeding. No differences were noted in uterine artery Doppler waveforms among patients with and without first trimester vaginal bleeding. Among patients with first trimester vaginal bleeding, 9 (14%) had a bilateral uterine artery notch and 56 (86%) did not, compared with 51 (24%) and 161 (76%), in the control group, respectively. Patients with first trimester vaginal bleeding, and a bilateral uterine artery notch had significantly higher rates of small for gestational age neonates, low-Apgar scores (<7) at one minute and cesarean deliveries compared to patients with first trimester vaginal bleeding who did not have bilateral uterine artery notch.

CONCLUSION

First trimester vaginal bleeding was not associated with a higher incidence of abnormal uterine artery waveforms or with placental related conditions. However, adverse perinatal outcomes were found when first trimester vaginal bleeding was associated with second and third trimester bilateral uterine artery notchs.

Maternal plasma concentrations of angiogenic/antiangiogenic factors in the third trimester of pregnancy to identify the patient at risk for stillbirth at or near term and severe late preeclampsia

OBJECTIVE

To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30-34 weeks of gestation can identify patients at risk for stillbirth, late preeclampsia, and delivery of small-for-gestational-age (SGA) neonates.

STUDY DESIGN

A prospective cohort study included 1269 singleton pregnant women from whom blood samples were obtained at 30-34 weeks of gestation and who delivered at >34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of late (>34 weeks of gestation) preeclampsia, severe late preeclampsia, stillbirth, and SGA was 3.2% (n = 40), 1.8% (n = 23), 0.4% (n = 5), and 8.5% (n = 108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late preeclampsia (adjusted odds ratio, 16); the addition of PlGF/sEng to clinical risk factors increased the area under the receiver-operating characteristic curve from 0.76 to 0.88 (P = .03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20-25 weeks of gestation for the prediction of severe late preeclampsia (comparison of areas under the receiver-operating characteristic curve; each P ≤ .02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false-positive rate of 15% for the identification of severe late preeclampsia. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30-34 weeks of gestation had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80%; specificity 93%) were observed in a separate case-control study.

CONCLUSION

Risk assessment for stillbirth and severe late preeclampsia in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and antiangiogenic factors at 30-34 weeks of gestation.

The influence of pregnancy on systemic immunity

Adaptations in maternal systemic immunity are presumed to be responsible for observed alterations in disease susceptibility and severity as pregnancy progresses. Epidemiological evidence as well as animal studies have shown that influenza infections are more severe during the second and third trimesters of pregnancy, resulting in greater morbidity and mortality, although the reason for this is still unclear. Our laboratory has taken advantage of 20 years of experience studying the murine immune response to respiratory viruses to address questions of altered immunity during pregnancy. With clinical studies and unique animal model systems, we are working to define the mechanisms responsible for altered immune responses to influenza infection during pregnancy and what roles hormones such as estrogen or progesterone play in these alterations.

The obstetric syndromes: clinical relevance of placental hormones

Preterm delivery, preeclampsia and intrauterine growth restriction are the major diseases of pregnancy. A key role in their pathogenesis is played by the placenta, which is the source of hormones and other important regulatory molecules providing the metabolic and endocrine homeostasis of the fetal-placental unit. Since obstetric syndromes are characterized by important maternal and neonatal morbidity and mortality worldwide, numerous efforts have been made over the years to prevent and treat them. Due to their complex pathogenesis, however, the therapy is poor and not very effective. Therefore, great emphasis is currently given to the prevention of these diseases through the identification of biochemical and biophysical markers, among which placental factors play a crucial role. The increasing knowledge of the role of placental molecules can indeed lead to the development of new therapeutic and diagnostic tools.

Circulating levels of neutrophil gelatinase-associated lipocalin (NGAL) correlate with the presence and severity of preeclampsia

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as a reliable marker of acute renal injury and is produced at the maternal-fetal interface but its role in preeclampsia has not been systematically examined. This study investigated whether plasma NGAL concentrations changed in patients with preeclampsia at diagnosis compared to normotensive controls.

STUDY DESIGN

A case-control study was performed. Plasma was collected from women with preeclampsia and normotensive controls matched for age, gestational age, and body mass index. Plasma NGAL concentrations were measured by specific enzyme-linked immunosorbent assay.

RESULTS

Patients with preeclampsia had significantly higher NGAL concentrations than controls (median [range]: 203.8 ng/mL [66.1-575.4] vs. 122.8 ng/mL [7.0-669.7]; P = .047). In subgroup analysis, patients with severe preeclampsia had significantly higher NGAL concentrations than those with mild preeclampsia. Plasma NGAL concentrations were positively correlated with the amount of proteinuria in women with preeclampsia (P = .003).

CONCLUSIONS

Plasma NGAL concentrations were significantly elevated in women with preeclampsia versus normotensive controls, and concentrations appear to be associated with the severity of the disease.

Hyperemesis gravidarum and risks of placental dysfunction disorders: a population-based cohort study

Objective

To study whether pregnancies complicated by hyperemesis gravidarum in the first (<12 weeks) or second (12–21 weeks) trimester are associated with placental dysfunction disorders.

Design

Population-based cohort study.

Setting

Sweden.

Population

All pregnancies in the Swedish Medical Birth Register estimated to have started on 1 January 1997 or later and ended in a single birth on 31 December 2009 or earlier (n = 1 156 050).

Methods

Odds ratios with 95% confidence intervals were estimated for placental dysfunction disorders in women with an inpatient diagnosis of hyperemesis gravidarum, using women without inpatient diagnosis of hyperemesis gravidarum as reference. Risks were adjusted for maternal age, parity, body mass index, height, smoking, cohabitation with the infant's father, infant's sex, mother's country of birth, education, presence of hyperthyreosis, pregestational diabetes mellitus, chronic hypertension and year of infant birth.

Main outcome measures

Placental dysfunction disorders, i.e. pre-eclampsia, placental abruption, stillbirth and small for gestational age (SGA).

Results

Women with hyperemesis gravidarum in the first trimester had only a slightly increased risk of pre-eclampsia. Women with hyperemesis gravidarum with first admission in the second trimester had a more than doubled risk of preterm (<37 weeks) pre-eclampsia, a threefold increased risk of placental abruption and a 39% increased risk of an SGA birth (adjusted odds ratios [95% confidence intervals] were: 2.09 [1.38–3.16], 3.07 [1.88–5.00] and 1.39 [1.06–1.83], respectively).

Conclusions

There is an association between hyperemesis gravidarum and placental dysfunction disorders, which is especially strong for women with hyperemesis gravidarum in the second trimester.

First-trimester metabolomic detection of late-onset preeclampsia

OBJECTIVE

We sought to identify first-trimester maternal serum biomarkers for the prediction of late-onset preeclampsia (PE) using metabolomic analysis.

STUDY DESIGN

In a case-control study, nuclear magnetic resonance-based metabolomic analysis was performed on first-trimester maternal serum between 11(+0)-13(+6) weeks of gestation. There were 30 cases of late-onset PE, i.e., requiring delivery ≥37 weeks, and 59 unaffected controls. The concentrations of 40 metabolites were compared between the 2 groups. We also compared 30 early-onset cases to the late-onset group.

RESULTS

A total of 14 metabolites were significantly elevated and 3 significantly reduced in first-trimester serum of late-onset PE patients. A complex model consisting of multiple metabolites and maternal demographic characteristics had a 76.6% sensitivity at 100% specificity for PE detection. A simplified model using fewer predictors yielded 60% sensitivity at 96.6% specificity. Strong separation of late- vs early-onset PE groups was achieved.

CONCLUSION

Significant differences in the first-trimester metabolites were noted in women who went on to developed late-onset PE and between early- and late-onset PE.