Trophoblast debris extruded from preeclamptic placentae activates endothelial cells: A mechanism by which the placenta communicates with the maternal endothelium

Introduction

Preeclampsia is characterized by maternal endothelial dysfunction. While the mechanisms leading to preeclampsia are unclear, a factor(s) from the placenta is responsible for triggering the disease. One placental factor implicated in triggering preeclampsia is trophoblast debris which may transmit pathogenic signals from the placenta to endothelial cells. In this study, we investigated whether trophoblast debris from preeclamptic placentae triggered endothelial cell activation.

Methods

Trophoblast debris from preeclamptic or normotensive placentae, or trophoblast debris from normal placental explants that had been cultured with preeclamptic (n = 14) or normotensive sera (n = 14) was exposed to endothelial cells. Activation of the endothelial cells was quantified by cell surface ICAM-1 and U937 adhesion to endothelial cells. The levels of IL-1β, pro-caspase-1 and active caspase-1 in the trophoblast debris were measured.

Results

Compared to controls, the levels of ICAM-1 and U937 adhesion to endothelial cells were significantly increased following exposure of the endothelial cells to trophoblast debris from preeclamptic placentae or placentae treated with preeclamptic sera. The levels IL-1β, pro-caspase-1 and active caspase-1 were significantly increased in both trophoblast debris from preeclamptic placentae and placentae treated with preeclamptic sera.

Discussion

These results provide the first direct evidence that trophoblast debris produced from preeclamptic placentae or placentae treated with preeclamptic sera can activate the endothelium.

Conclusions

Trophoblast debris from preeclamptic but not normotensive placentae can induce endothelial cell activation. This may be one mechanism by which the preeclamptic placenta communicates with the maternal endothelium to induce activation of the endothelium.     

JunB/Cyclin-D1 imbalance in placental mesenchymal stromal cells derived from preeclamptic pregnancies with fetal-placental compromise

Introduction

In the present study, we characterized the expression of Activating Protein 1 (AP-1) factors, key cell cycle regulators, in primary placental mesenchymal stromal cells (PDMSCs) derived from normal and preeclamptic (PE) pregnancies with fetal-placental compromise.

Methods

PDMSCs were isolated from control (n = 20) and preeclamptic (n = 24) placentae. AP-1 expression was determined by semi-quantitative RT-PCR (sqRT-PCR), Real Time PCR and Western Blot assay. PDMSCs were plated and JunB siRNA was performed. JunB and Cyclin-D1 expression were assessed by Real Time and Western Blot analyses.

Results

JunB expression was significantly increased while Cyclin-D1 expression was significantly down-regulated in PE relative to control PDMSCs. JunB siRNA was accompanied by JunB down-regulation and increased Cyclin-D1 in normal PDMSCs.

Conclusions

We described, for the first time, AP-1 expression in PDMSCs derived from physiological and PE placentae. Importantly, we demonstrated that JunB over-expression in PE-PDMSCs affects Cyclin-D1 regulation. Our data suggest a possible contribution of these pathological placental cells to the altered cell cycle regulation typical of preeclamptic placentae.     

Unfractionated heparin and placental pathology in high-risk pregnancies: Secondary analysis of a pilot randomized controlled trial

Introduction

Heparin is often prescribed during pregnancy with the intention of improving perinatal outcomes on the basis that it exerts an anticoagulant action in the inter-villous space. Accumulating in-vitro and in-vivo evidence indicates that heparin's beneficial effects in pregnancy may result from ‘non-anticoagulant’ effects including the promotion of angiogenesis.

Methods

To study the effect of heparin within the placenta, we performed secondary analyses on a pilot trial where 32 women with negative thrombophilia screens and second-trimester evidence of placental insufficiency were randomized to standard care or antenatal self-administration of unfractionated heparin (UFH) 7500IU twice-daily. Serial placental ultrasound images were reviewed and compared with histo-pathologic findings following delivery.

Results

There were no differences between the two arms in either the evolution of abnormal placental lesions on ultrasound (p = 0.75) or evidence of maternal vascular under-perfusion on histopathology (p = 0.89). In pregnancies considered at increased risk for adverse pregnancy outcomes based on previous history or abnormal serum marker screen, early (second-trimester) placental ultrasound, reflecting developmental pathology had better test characteristics (sensitivity 77.8%; positive predictive value 80.8%) for predicting adverse pregnancy outcomes than third-trimester ultrasound that is reflective of placental thrombotic injury.

Conclusions

Administration of UFH did not prevent the development or evolution of abnormal placental lesions on placental ultrasound or evidence of maternal vascular underperfusion on placental histo-pathology. Second-trimester placental ultrasound may be of value in predicting those at greatest risk of adverse outcomes.     

Increased expression levels of E-cadherin,cytokeratin 18 and 19 observed in preeclampsia were not correlated with disease severity

Introduction

Preeclampsia is a pregnancy-specific disorder and placental factor(s) contribute to the pathogenesis of preeclampsia. Turnover of villous trophoblast is affected by impaired placental perfusion in preeclampsia. Expression and localisation of cadherins and cytokeratins are involved in the pathogenesis of preeclampsia. However, studies describing the associations between cadherins and cytokeratins in preeclampsia are limited. The aim of this study was to investigate the expression of E-cadherin, N-cadherin, cytokeratin 18 and cytokeratin 19 in placentae from women with preeclampsia in order to determine whether their expression differs with disease severity.

Methods

29 preeclamptic placentae and 25 normotensive placentae were included in this study. The expression of E-cadherin, cytokeratin 18, cytokeratin 19 andN-cadherin was quantified by immunohistochemistry and western blotting.

Results

E-cadherin, cytokeratin 18 and cytokeratin 19 were expressed predominantly in the syncytiotrophoblast of the placenta and the expression of E-cadherin, cytokeratin 18 and cytokeratin 19 was significantly increased in preeclampsia compared to normotensive pregnancies. However, there was no significant difference in expression between severe preeclampsia and mild preeclampsia. In addition, there was no difference in the expression of N-cadherin between preeclampsic and normotensive pregnancies.

Discussion

Our data demonstrated increased expression of E-cadherin, cytokeratin 18 and cytokeratin 19 in the syncytiotrophoblast of preeclamptic placentae, but this increase was not correlated with disease severity.

Conclusion

Our data suggests that E-cadherin and cytokeratins are involved in the pathogenesis of preeclampsia.     

Velocimetría Doppler del flujo sanguíneo de la arteria uterina y riesgo de muerte perinatal en preeclámpsicas

Objective

To determine the association between Doppler velocimetry values of uterine artery blood flow with the risk of perinatal death in preeclamptic patients.

Materials and method

We selected 80 patients with a diagnosis of preeclampsia. Preeclamptic patients were divided into those with perinatal deaths and those without. The variables analyzed were the pulsatility index, the resistance index, and the systolic/diastolic flow ratio of the uterine arteries.

Results

There were no differences in maternal age, height or weight between preeclamptic patients with or without perinatal deaths (p = ns), or between gestational age at the time of Doppler ultrasound and systolic and diastolic blood pressure (p = ns). The pulsatility index (1.206 ± 0.140) and resistance index (0.684 ± 0.098) of the uterine arteries were significantly higher in women with perinatal deaths than in those without (1.113 ± 0.109 and 0.605 ± 0.116, respectively; P<.05). No significant differences were found in mean values of the systolic/diastolic flow ratio of the uterine arteries (p = ns).

Conclusion

A high value of the pulsatility index and resistance index of the uterine arteries on Doppler velocimetry in preeclamptic patients is associated with an increased risk of perinatal death.     

Effect of pregestational diabetes mellitus on first trimester placental characteristics: Three-dimensional placental volume and power Doppler indices

Objective

To investigate whether pregestational diabetes mellitus (DM) induces changes in vascular placental development detectable at first trimester.

Methods

This was a prospective case–control study in 69 women with pregestational DM and 94 controls undergoing first-trimester combined screening for aneuploidies. Maternal characteristics, fetal nuchal translucency thickness, maternal serum pregnancy-associated plasma protein A (PAPP-A) and free β human chorionic gonadotrophin (β-hCG) were evaluated. Three-dimensional ultrasound was used to measure placental volume and three dimensional power Doppler (3D-PD) placental vascular indices including: vascularization index (VI), flow index (FI) and vascularization flow index (VFI). Pregnancy-associated hypertensive complications (PAHC) and perinatal outcomes were analyzed. The total group of diabetic women and the group of diabetic women without PAHC were compared separately with the control group.

Results

3D-PD placental vascular indexes were significantly lower in women with DM than in controls (VI p = 0.007, FI p = 0.003 and VFI p = 0.04). These differences remained on excluding cases with PAHC in the DM group. No differences were found in placental volumes between the DM group and controls. Serum PAPP-A levels were also lower in diabetic women (p < 0.02) and negatively correlated with the degree of maternal metabolic control at first trimester.

Conclusions

Pregestational DM induces demonstrable alterations in first trimester placental development, with significantly reduced placental vascularization indices and PAPP-A values. This effect is independent of the later development of PAHC.     

Placental findings in late-onset SGA births without Doppler signs of placental insufficiency

Objectives

To describe placental pathological findings in late-onset small-for-gestational age (SGA) births for which Doppler signs of placental insufficiency are lacking.

Methods

A series of placentas were evaluated from singleton pregnancies of SGA births (birth weight below the 10th percentile) delivered after 34 weeks with normal umbilical artery Doppler (pulsatility index below the 95th percentile), that were matched by gestational age with adequate-for-gestational age (AGA) controls. Using a hierarchical and standardized system, placental lesions were classified histologically as consequence of maternal underperfusion, fetal underperfusion or inflammation.

Results

A total of 284 placentas were evaluated (142 SGA and 142 AGA). In the SGA group, 54.2% (77/142) of the placentas had weights below the 3rd percentile for GA while it was a 9.9% (14/142) in the AGA group (p < 0.001). Only 21.8% (31/142) of SGA placentas were free of histological abnormalities, while it was 74.6% (106/142) in the AGA group (p < 0.001). In the abnormal SGA placentas (111/142) there were a total of 161 lesions, attributable to MUP in 64% (103/161), FUP in 15.5% (25/161), and inflammation in 20.5% (33/161).

Discussion

In most placentas of term SGA neonates with normal UA Doppler histological abnormalities secondary to maternal underperfusion prevail, reflecting latent insufficiency in uteroplacental blood supply. This is consistent with the higher risk of adverse perinatal outcome reported in this population and underscores a need for new markers of placental disease.

Conclusions

A significant proportion of late-onset SGA births with normal umbilical artery Doppler may still be explained by placental insufficiency.     

2D-ultrasound and endocrinologic evaluation of placentation in early pregnancy and its relationship to fetal birthweight in normal pregnancies and pre-eclampsia

Objectives

To study the relationships between 2D ultrasound measurements of placentation and maternal serum (MS) levels of PAPP-A, inhibin A and fβhCG in early pregnancy and subsequent fetal growth in pregnancies with a normal and abnormal outcome.

Study design

Prospective population-based cohort study of 301 pregnancies with a normal outcome, 18 with a pregnancy complicated by pre-term delivery (PTD) and 14 with subsequent pre-eclampsia (PE).

Main outcome measures

Basal placental surface area, placental thickness, ellipsivity and volume; MS PAPP-A and fβhCG at 11–13 + 6 weeks, MS inhibin A at 15–22 weeks and birthweight centile at delivery.

Results

In the normal group, the basal surface area showed a significantly (P < 0.001) positive correlation with placental thickness and placental ellipsivity. With the exception of placental ellipsivity, all other placental ultrasound parameters were significantly related with birthweight centile. Inhibin A showed a significant (P < 0.005) correlation with birthweight centiles. The basal plate surface area and MS PAPP-A were significantly (P < 0.01 and P < 0.001, respectively) lower and MS inhibin A significantly (P < 0.01) higher in PE than in controls. No changes were found in pregnancies complicated by PTD.

Conclusion

The basal plate surface area at 11–14 weeks reflects indirectly normal and abnormal placentation and development of the definitive placenta. Combined with MS PAPP-A and/or inhibin A levels this parameter could be useful in identifying from the end of the first trimester, pregnancies subsequently complicated with PE.     

Human placental multipotent mesenchymal stromal cells modulate trophoblast migration via Rap1 activation

Introduction

Little is known about the interaction between human placental multipotent mesenchymal stromal cell (hPMSC) and trophoblast. We hypothesize that hPMSCs produce hepatocyte growth factor (HGF) which may interact with trophoblasts and regulate their migration during placentation.

Methods

hPMSCs were isolated from term placentas and conditioned medium was collected after 2 days of culture in hypoxic (<1% O₂) or control (20% O₂) conditions. Selective agonist and inhibitor or siRNA for protein kinase A (PKA) or Rap1 were combined with Rap1-GTP pull down assays, flow cytometry, integrin β1 activation assays and adhesion and migration studies to investigate HGF signaling effects in trophoblasts. The hPMSC abundance and HGF level in preeclamptic placentas were compared with gestational age-matched controls.

Results

HGF was expressed by hPMSCs and was decreased in hypoxia. HGF induced cAMP production and Rap1 activation in trophoblasts, which in turn activated integrin β1. The HGF and PKA activator 6-Bnz-cAMP induced Rap1 activation with increased trophoblast adhesion and migration. The alterations were inhibited by PKA inhibitor H89 or Rap1 siRNA. HGF and cAMP expression were reduced in preeclamptic placentas. hPMSC number was decreased in preeclamptic placenta compared to controls (0.68 ± 0.1% vs. 1.32 ± 0.5%; P = 0.026). hPMSC conditioned medium enhanced trophoblast migration which was inhibited by c-Met blocking antibody, but migration was reduced by conditioned medium from hPMSC cultured in hypoxia.

Conclusions

hPMSCs secrete HGF and increase trophoblast cAMP production. The cAMP effector PKA modulates adhesion and migration of trophoblast via signaling to Rap1 and integrin β1.     

Do placental histologic findings of chorion-decidual hemorrhage or inflammation in spontaneous preterm birth influence outcomes in the subsequent pregnancy?

Introduction

Spontaneous preterm birth (SPTB) is the common endpoint of different underlying etiologies, including chorion-decidual bleeding and inflammation. However, specific histologic findings from a prior pregnancy do not always inform clinical management in subsequent pregnancies secondary to few prior studies having evaluated the relationship between prior pregnancy pathology and subsequent outcomes in patients with SPTB.

Methods

Included subjects had: 1) a SPTB with available placental pathology and 2) a subsequent consecutive delivery at >20 weeks gestational age at our institution. For included subjects archived placenta and membrane paraffin blocks from the index SPTB were cut, stained with Prussian Blue and evaluated by a perinatal pathologist for the presence of hemosiderin. The association between histologic findings and subsequent pregnancy outcomes were evaluated through logistic and linear regression.

Results

A total of 131 subjects were included, of whom 39.7% had a recurrent SPTB. Funisitis at the time of preterm delivery significantly increased the risk of early (<34 weeks) recurrent preterm birth (OR 3.38, p = 0.016), though this may have been confounded by gestational age at delivery. Several histologic features were significantly associated with reductions in birth weight in the subsequent pregnancies, even if they did not increase the risk of recurrent preterm birth.

Discussion

The presence of chorion-decidual bleeding or inflammation in a prior pregnancy can signal an increased risk in a future pregnancy beyond the recurrent risk of SPTB itself.

Conclusions

Placental histologic findings after SPTB maybe associated with differences in birth weight in a subsequent pregnancy.     

Lipocalin2 enhances the matrix metalloproteinase-9 activity and invasion of extravillous trophoblasts under hypoxia

Objectives

The invasion of extravillous trophoblasts (EVTs) to the decidua and spiral arteries in early pregnancy is a crucial step for a successful pregnancy; however, its mechanisms are not fully understood. Lipocalin2 (LCN2), a multifunctional secretory protein known as neutrophil gelatinase-associated lipocalin (NGAL), reportedly enhanced invasiveness via the activation of matrix metalloproteinase-9 (MMP-9) in several cancer cells. In this study, the expression and function of LCN2 in early placenta were analyzed.

Methods

Early placental tissues between 7 and 10 weeks of gestation were obtained from normal pregnant women who underwent elective termination. The expression of LCN2 was examined using immunostaining and RT-PCR. EVTs isolated from these placental tissues and a choriocarcinoma cell line (JAR) were used to investigate the effects of LCN2 on proliferation, invasion potential, and MMP-9 activity under hypoxia using a WST-1 assay, Matrigel invasion assay, and gelatin gel zymography, respectively.

Results

The immunohistochemical expression of LCN2 was observed in the cytoplasm of EVTs, cytotrophoblasts and the decidua, but not in syncytiotrophoblasts. The addition of recombinant LCN2 did not affect proliferation, but enhanced the invasiveness (500 ng/mL, p < 0.01) and MMP-9 activity of primary cultured EVTs and JAR in a dose-dependent manner. Silencing LCN2 using shRNA reduced the invasiveness (p < 0.01) and MMP-9 activity of JAR. In addition, the hypoxic condition (2% O₂) increased LCN2 expression (p < 0.01), MMP-9 activity, and invasive ability (p < 0.01).

Conclusions

LCN2 was involved in the invasiveness of EVTs, especially under hypoxia, via increased MMP-9 activity.     

The clinical significance of large placental lakes

Objective

The aim of our study was to establish whether there is a correlation between the size of placental lakes and adverse pregnancy outcome.

Study design

Target ultrasonography for diagnosis of placental lake was performed in the 2nd trimester of pregnancy and followed up in the 3rd trimester. Placental lakes were defined as homogenous sonolucent avillous lesions greater than 2 cm × 2 cm in diameter. The 109 pregnant women enrolled in this study were divided into four groups according to the size and change in size of placental lakes. Clinical characteristics and pregnancy outcomes in each group were compared.

Results

Some placental lakes decreased and disappeared, whereas others persisted. There were no significant differences in clinical characteristics among the four investigated groups. Fetal small-for-gestational-age status was significantly correlated with large placental lakes, compared to small.

Conclusion

Large placental lakes were correlated with the fetal status of small for gestational age. Therefore, if a large placental lake is identified in the 2nd trimester of pregnancy, appropriate surveillance should be considered for the remainder of the pregnancy.     

Soluble endoglin production is upregulated by oxysterols but not quenched by pravastatin in primary placental and endothelial cells

Introduction

Preeclampsia is a serious pregnancy complication. Soluble endoglin (sEng) is released from the placenta and contributes to the maternal endothelial dysfunction seen in preeclampsia. Recently oxysterols, which activate the Liver X Receptor (LXR), have been implicated in producing sEng, by upregulating matrix metalloproteinase-14 (MMP14; cleaves endoglin to produce sEng) and down-regulating tissue inhibitor of metalloproteinase-3 (TIMP-3; inhibitor of MMP14). The functional experiments in that study were performed on JAR cells (human choriocarcinoma cell line) and placental explants.

Methods

We characterized LXR in severe preeclamptic placentas, and assessed whether oxysterols increase release of sEng from primary human umbilical vein endothelial cells (HUVECs), primary trophoblasts and placental explants. Given pravastatin is thought to block oxysterol production and inhibit the LXR, we examined whether pravastatin reduces sEng release.

Results

LXRα and β were localized to the syncytiotrophoblast and villous tips and were significantly up-regulated in preeclamptic placenta. Oxysterols upregulated sEng production in HUVECs and placental explants although the increases were far more modest than that recently reported. Oxysterols did not upregulate sEng in primary trophoblasts. Furthermore, mRNA expression of MMP14 and TIMP-3 were not altered by oxysterols in any tissue. Surprisingly, pravastatin did not decrease oxysterol-induced upregulation of sEng.

Discussion

LXR is up-regulated in preeclamptic placenta. Oxysterols upregulate sEng production from human tissues, but the increase is modest, suggesting this may not be the main mechanism for the very significant elevations in sEng seen in preeclampsia. Pravastatin does not decrease sEng production.

Conclusion

Oxysterols modestly up-regulate sEng production which is not quenched by pravastatin.     

The risk of placental abruption and placenta previa in pregnant women with chronic hepatitis B viral infection: A systematic review and meta-analysis

Introduction

Several epidemiological studies have found a positive association between chronic hepatitis B virus (CHB) infection and the risk of placental abruption and placenta previa, but various studies have reported conflicting findings. The objective was to systematically review the literature to determine a possible association between CHB infection and these two placental complications.

Methods

We conducted a computerized search in electronic database through March 1, 2014, supplemented with a manual search of reference lists, to identify original published research on placental abruption and placenta previa rates in women with CHB infection. Data were independently extracted, and relative risks were calculated. The meta-analysis was performed using Stata version 10.0 software.

Results

Five studies involving 9088 placenta previa cases were identified. No significant association between CHB infection and placenta previa was identified (OR = 0.98, 95% CI = 0.60–1.62). Five studies involving 15571 placental abruption cases were identified. No significant association between CHB infection and placental abruption was identified (OR = 1.42, 95% CI, 0.93–2.15).

Discussion

The immune response against the virus represents a key factor in determining infection outcomes. No observation of significant increased risk of the placental complications could be partially explained by the complex immune response during CHB infection.

Conclusions

Our meta-analysis found no evidence of significant associations between CHB infection and increased risk of placental abruption as well as placenta previa. Further well-designed studies were warranted to assess any potential association between CHB infection and increased risk of placental abruption as well as placenta previa.     

Angiogenic factors at diagnosis of late-onset small-for-gestational age and histological placental underperfusion

Objective

This study was designed to explore the association between angiogenic factors levels at diagnosis of small-for-gestational age (SGA) and placental underperfusion (PUP).

Methods

In a cohort of SGA singleton pregnancies, each delivered at >34 weeks, uterine (UtA), umbilical (UA), and middle cerebral (MCA) arteries were evaluated by Doppler upon diagnosis of SGA status. In addition, maternal circulating concentrations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were assayed by ELISA, and each placenta was evaluated for histologic signs of PUP using a hierarchical and standardized classification system. Logistic regression was applied to analyze independent relationships (at diagnosis) between angiogenic factors and Doppler parameters.

Results

A total of 122 suspected SGA pregnancies were studied, 70 (57.4%) of which ultimately met PUP criteria. In this group, 85 placental findings qualified as PUP. Both mean UtA pulsatility index z-values (1.26 vs. 0.84; p = 0.038) and PlGF multiples of normal median (0.21 vs. 0.55; p = 0.002) differed significantly in pregnancies with and without PUP, respectively. By logistic regression, PlGF alone was independently predictive of PUP (OR = 0.11 [95% CI 0.025–0.57]; p = 0.008).

Discussion

Histologic placental abnormalities in term SGA neonates reflect latent insufficiency in uteroplacental blood supply. The heightened risk of adverse perinatal outcomes in this context underscores a need for new Doppler or biochemical prenatal markers of placental disease. Angiogenic factors may be pivotal identifying SGA neonates.

Conclusions

Diminished circulating levels of placental growth factor, determined upon discovery of SGA status, are associated with histologic evidence of PUP.     

Pre-treatment with calcium prevents endothelial cell activation induced by multiple activators,necrotic trophoblastic debris or IL-6 or preeclamptic sera: Possible relevance to the pathogenesis of preeclampsia

Introduction

A hallmark of preeclampsia is endothelial cell dysfunction/activation in response to “toxins” from the placenta. Necrotic trophoblastic debris (NTD) is one possible placental toxin and others include inflammatory cytokines. Calcium supplementation appears to protect “at-risk” women from developing preeclampsia by an unknown mechanism. In this study we investigate whether the addition of high levels of calcium to endothelial cells prior to their exposure to the preeclampsia-associated activators could reduce the endothelial cell activation.

Methods

NTD was harvested from 1st trimester placental explants. Endothelial cells were treated with varied concentrations of calcium prior to exposure to NTD, IL-6 or preeclamptic sera or low levels of calcium. Activation was monitored by quantifying endothelial cell-surface ICAM-1 by ELISA or U937 adhesion to endothelial cells. The activity of endothelial cell nitric oxide synthetase was blocked with L-NAME.

Results

Pre-treatment with increasing concentrations of calcium inhibited the activation of endothelial cells in response to NTD or IL-6 or preeclamptic sera. Inhibiting nitric oxide synthetase, using L-NAME, reduced the ability of high calcium levels to protect endothelial cell activation. Pre-treatment with calcium did not prevent endothelial cell activation induced by the reduction of the levels of calcium but additional calcium treatment did prevent endothelial cell activation induced by low calcium.

Conclusion

Our results demonstrate calcium supplementation may prevent the activation of the endothelium in response to activators. These results may partially explain the benefits of calcium supplementation in the reduction of risk for developing preeclampsia and provide in vitro mechanistic support for the use of calcium supplementation in at-risk women.     

Comparison of serum and urinary nephrin levels between normal pregnancies and severe preeclampsia

Objective

To compare the levels of urinary excretion of nephrin in women experiencing either normotensive or severe preeclamptic pregnancies, and to examine the relationship between urinary nephrin levels and clinical parameters of preeclampsia.

Study design

In a case control study we collected serum and urine specimens from women with normal pregnancy (n = 30) and from women with severe preeclampsia (n = 43). Serum nephrin levels and urinary nephrin concentrations were measured in all patients.

Results

Both serum and urine concentrations of nephrin were significantly higher in the severe preeclamptic group than in the normal pregnancy group. In addition, we identified a significant relationship between urinary nephrin levels and urine protein concentrations in the severe preeclamptic group. Urine nephrin concentrations were also correlated with serum creatinine levels and with diastolic blood pressure in the severe preeclamptic group.

Conclusion

The positive correlations observed in this study suggest that urinary nephrin excretion might play an important role in the pathogenesis of proteinuria during preeclampsia and could be a good indicator of renal damage.     

Laser surgery in twin–twin transfusion syndrome with proximate cord insertions

Objective

To estimate the prevalence of proximate cord insertions in twin–twin transfusion syndrome (TTTS) and evaluate the outcome after fetoscopic laser coagulation surgery.

Methods

We included all TTTS cases treated with laser at our center between 2002 and 2013. Placentas were examined after birth and injected with colored dye. TTTS cases without complete placental injection study were excluded. We recorded the presence of proximate cord insertions (distance < 5 cm) after birth and the presence and types of residual anastomoses. We compared the clinical outcome and placental findings in cases with and without proximate cord insertions.

Results

The prevalence of proximate cord insertions in TTTS placentas was 2% (4/252). Perinatal mortality in the TTTS group with and without proximate cord insertions was 13% (1/8) and 12% (61/496), respectively (P = 1.0). Residual anastomoses were detected in all placentas with proximate cord insertions (100%, 4/4) compared to 27% (66/248)(P < .01) in TTTS placentas without proximate cord insertions.

Conclusion

Fetoscopic laser coagulation in TTTS cases with proximate cord insertions is challenging due to technical difficulties in visualizing the vascular equator and results in an increased risk of incomplete laser treatment.     

Analysis of placental vascularization in a pharmacological rabbit model of IUGR induced by l-NAME,a nitric oxide synthase inhibitor

Objectives

We have previously validated the use of l-nitro-arginine methyl ester (l-NAME), a nitric oxide synthase inhibitor, to induce placental hypoperfusion in a rabbit model. Here, the effects of l-NAME on placental vascularization were explored. Transplacental transfer of l-NAME and/or its active metabolite, NG-nitro-l-arginine (L-NOARG), was evaluated.

Methods

25 pregnant female rabbits were allocated on day 24 to one of 5 groups: l-NAME groups (31.35, 62.5, 125 and 250 mg/kg/day) or Control group (C). On Day 28, the labyrinthine area was analyzed for stereology and gene expression. l-NAME and L-NOARG were quantified in maternal and fetal blood.

Results

The volume density of fetal vessels was significantly decreased in l-NAME (including 62.5–250 mg/kg/day which induced an IUGR) compared to C groups. l-NAME induced an increase of the volume and surface density of the maternal blood space. The trophoblast volume density remained unchanged as well as the surface density of fetal vessels. Relative expression of eNOS, VEGFA, VEGFR-1 and VEGFR-2 in placentas was not affected by 125 mg/kg/day l-NAME treatment, whereas IGF-2 expression was significantly increased in this l-NAME group compared to C. l-NAME was not detected in maternal nor fetal plasma. In contrast, fetal to maternal L-NOARG ratio was 100% in all l-NAME groups.

Conclusion

These data demonstrate that l-NAME induced placental hypovascularization. The active L-NOARG metabolite is found in maternal and fetal plasma at similar concentrations. This could impact the fetal growth and reduces the interest of this model to study fetal outcomes of placental hypoperfusion.