Placental angiogenic growth factors and uterine artery Doppler findings for characterization of different subsets in preeclampsia and in isolated intrauterine growth restriction

Evaluation of an optimal gestational age cut-off for the definition of early- and late-onset fetal growth restriction

OBJECTIVE

The terms early- and late-onset fetal growth restriction (FGR) are commonly used to distinguish two phenotypes characterized by differences in onset, fetoplacental Doppler, association with preeclampsia (PE) and severity. We evaluated the optimal gestational age (GA) cut-off maximizing differences among these two forms.

PATIENTS AND METHODS

A cohort of 656 consecutive singleton pregnancies with FGR was created. We used the decision tree analysis to evaluate the GA cut-off that best discriminated perinatal mortality, association with PE and adverse perinatal outcome (fetal demise, early neonatal death, neonatal acidosis at birth, and 5-min Apgar score <7).

RESULTS

We identified 32 weeks at diagnosis as the optimal cut-off, resulting in two groups with 7.1 and 0%, p < 0.001 perinatal mortality, 35.1 and 12.1%, p < 0.001 association with PE, and 13.4 and 4.6%, p < 0.001 composite adverse perinatal outcome. Abnormal versus normal umbilical artery (UA) Doppler classified two groups with 10.6 and 0.2%, p < 0.001 perinatal mortality, 50.0 and 11.8%, p < 0.001 association with PE, and 18.2 and 4.2%, p < 0.001 composite adverse perinatal outcome.

CONCLUSIONS

UA Doppler discriminated better the two forms of FGR with average early- and late-onset presentation, higher association with PE and poorer outcome. In the absence of UA information, a GA cut-off of 32 weeks at diagnosis maximizes differences between early- and late-onset FGR.

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.

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.

Expression of genes coding for proangiogenic factors and their receptors in human placenta complicated by preeclampsia and intrauterine growth restriction

The aim of the study was to investigate the expression of genes coding for vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF) as well as their receptors, fms-like tyrosine kinase receptor 1 (VEGFR-1/Flt-1) and VEGF receptor 2 (VEGFR-2/KDR) in the placentae of patients with pregnancies complicated by preeclampsia (PE) and intrauterine growth restriction (IUGR). Tissue samples were collected from placentae of women with PE (n=31) and IUGR syndrome (n=25) as well as of healthy control women (n=31). Total RNA was extracted and purified, mRNA reversely transcribed, and amplified using real-time PCR. Expression of the examined genes was normalized to β-actin. Higher levels of PlGF (p<0.001) and Flt-1 (p<0.05) transcription were found in PE placentae compared to normal ones. A positive correlation between PlGF and Flt-1 expression was revealed in the PE patients. In conclusion, the presented data indicate the upregulation of both PlGF and Flt-1 in placentae of women with PE, which could be induced by a pathological process possibly due to endothelial dysfunction.

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.

Evidence of an imbalance of angiogenic/antiangiogenic factors in massive perivillous fibrin deposition (maternal floor infarction): a placental lesion associated with recurrent miscarriage and fetal death

OBJECTIVE

Massive perivillous fibrin deposition (MPFD) is associated with serious complications of pregnancy including recurrent spontaneous abortion, fetal growth restriction, and fetal demise. The aim of this study was to determine whether maternal plasma concentrations of angiogenic/antiangiogenic factors in MPFD differ from those of uncomplicated pregnancies.

STUDY DESIGN

This retrospective longitudinal case-control study included MPFD cases (n = 10) and control patients (n = 175) with uncomplicated pregnancies who were enrolled in a longitudinal study and delivered at term. Serial plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor (sVEGFR)-1 and -2 were determined by an enzyme-linked immunosorbent assay (cases, n = 28 samples; controls, n = 723 samples). Individual analyte concentrations were averaged across gestational age at specimen collection intervals. Linear mixed models were used to test for differences in log-transformed mean analyte concentrations both overall and as a function of time.

RESULTS

The following results were found: (1) patients with MPFD had a lower mean plasma PlGF concentration (P = .03) and higher mean plasma concentrations of sVEGFR-1 and sEng (both P < .01) than controls, adjusted for potential confounders; (2) the mean plasma concentration of PlGF differed further among cases and controls as a function of gestational age interval (P < .0001); however, mean sVEGFR-1 and sEng group differences as a function of gestational age interval approached but did not reach significance (P = .09 and P = .11, respectively); (3) patients with MPFD had lower mean plasma concentrations of PlGF/sVEGFR-1 (P < .0001) and PlGF/sEng (P < .001): both of these relationships differed further as a function of gestational age interval (both P < .0001); and (4) differences in mean sVEGFR-1, sEng, and the ratios of PlGF to sVEGFR-1 and PlGF to sEng were observed before 20 weeks of gestation.

CONCLUSION

An imbalance of angiogenic/antiangiogenic factors is present in patients with MPFD prior to the diagnosis. We propose that these changes participate in the mechanisms responsible for adverse pregnancy outcomes in patients with MPFD.

THE EVIDENCE FOR LATE-ONSET PRE-ECLAMPSIA AS A MATERNOGENIC DISEASE OF PREGNANCY

It is our opinion that the evidence from epidemiological observations, clinical trials and biological studies is strong enough to support the view of different origin and phenotypes of pre-eclampsia: placental, which usually occurs (but not exclusively) early in pregnancy and is associated with poor early placentation of different severity with subsequent restriction of foetal growth, at different stages of gestation; and maternogenic, which generally occurs late in pregnancy and it is not related to placental insufficiency and foetal growth restriction.

Can maternal serum placental growth factor estimation in early second trimester predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction? A prospective cohort study

AIM

To determine whether maternal serum placental growth factor (PlGF) estimation in early second trimester (20-22 weeks of gestation) can predict the occurrence of early onset preeclampsia and/or early onset intrauterine growth restriction (IUGR).

MATERIAL AND METHODS

A prospective cohort study was conducted on 722 women with singleton pregnancies, screened from the antenatal clinic, and serum PlGF levels were estimated at 20-22 weeks of gestation. A cut-off value of <155 pg/mL for serum PlGF was determined by receiver operating characteristic (ROC) curve analysis for identifying pregnant women at risk of developing early onset preeclampsia and/or early onset IUGR. Preeclampsia and IUGR were classified as early onset when diagnosed by 32 weeks of gestation. Univariate logistic regression analysis was used to analyze the association between serum PlGF level <155 pg/mL and the two outcome measures (i.e. early onset preeclampsia and early onset IUGR) and odds ratio (OR) was computed. P-value < 0.05 was considered statistically significant.

RESULTS

Maternal serum PlGF level <155 pg/mL at 20-22 weeks of gestation had a strong association with early onset preeclampsia (OR 8.35; 95% CI 1.79-18.94; P = 0.007) and with early onset IUGR (OR 10.73; 95% CI 4.08-20.23; P = 0.000). The sensitivity of serum PlGF < 155 pg/mL for predicting early onset preeclampsia and early onset IUGR were 82 and 84, respectively.

CONCLUSION

Maternal serum PlGF level estimation in early second trimester (20-22 weeks of gestation) may be useful in predicting the occurrence of early onset preeclampsia and/or early onset IUGR.

Performance of a first-trimester screening of preeclampsia in a routine care low-risk setting

OBJECTIVE

We sought to evaluate the effectiveness of an integrated first-trimester screening test to predict preeclampsia (PE).

STUDY DESIGN

A prospective cohort of singleton pregnancies underwent routine first-trimester screening from 2009 through 2011 (n = 5759). A logistic regression-based predictive model for early- and late-onset PE was constructed based on: maternal characteristics; levels of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin at 8-12 weeks; and blood pressure and uterine artery Doppler at 11.0-13.6 weeks.

RESULTS

Of the 5170 enrolled participants, 136 (2.6%) developed PE (early PE: 26 [0.5%]; late PE: 110 [2.1%]). At 5% and 10% false-positive rates, detection rates were 69.2% and 80.8% for early PE (area under the curve, 0.95; 95% confidence interval, 0.94-0.98) and 29.4% and 39.6% for late PE (area under the curve, 0.71; 95% confidence interval, 0.66-0.76), respectively.

CONCLUSION

First-trimester screening combining maternal factors with uterine artery Doppler, blood pressure, and pregnancy-associated plasma protein-A is useful to predict PE in a routine care setting.

Serum placental growth factor as a predictor of early onset preeclampsia in overweight/obese pregnant women

The purpose of this study was to analyze whether maternal serum placental growth factor (PlGF) could predict early onset preeclampsia (<32 weeks of gestation) in overweight/obese pregnant women, and whether it could do it more effectively than in normal/underweight pregnant women. A prospective cohort study was conducted on 1678 pregnant women with singleton pregnancies, who were grouped as underweight, normal, overweight, and obese on the basis of body mass index, followed by serum PlGF estimation at 20 to 22 weeks of gestation. A cut-off value of <144 pg/mL for PlGF was determined by Receiver Operating Characteristic curve analysis to identify risk of early onset preeclampsia. Univariate logistic regression analysis revealed significantly stronger association between PlGF <144 pg/mL and early onset preeclampsia in overweight/obese pregnant women (odds ratio 7.64; 95% confidence interval 5.34-10.12; P = .000) than in normal/underweight pregnant women (odds ratio 2.95; 95% confidence interval 1.74-4.26; P = .007). Weight and PlGF levels in study women had a significant negative correlation (r = 0.663; P = .002). Serum PlGF in early second trimester could be an effective predictor of early onset preeclampsia in overweight/obese pregnant women and may be more effective than in normal/underweight pregnant women.

Abnormal second-trimester serum analytes are more predictive of preterm preeclampsia

OBJECTIVE

We sought to determine the association of abnormal second-trimester serum analytes with early preterm preeclampsia.

STUDY DESIGN

We conducted a retrospective study of 7767 subjects undergoing second-trimester serum aneuploidy screening. Values of maternal serum α-fetoprotein (AFP), β-human chorionic gonadotropin (hCG), and inhibin (INH) were calculated as multiples of the median (MoM) and evaluated by gestational age at delivery and occurrence of preeclampsia.

RESULTS

Of 459 (6.5%) cases of preeclampsia, 65 (14%) delivered <34 weeks and 394 (86%) delivered >34 weeks. Elevated AFP, hCG, and INH >2 MoM were associated with preeclampsia, and the odds ratio was higher for the development of preeclampsia <34 weeks than >34 weeks (odds ratio, 8.04 vs 2.91 for AFP, 3.6 vs 2 for hCG, and 4.17 vs 3.08 for INH, P < .001 for all). The higher the MoM for each analyte the greater the likelihood of preeclampsia.

CONCLUSION

Elevated AFP, hCG, and INH levels >2 MoM are associated with developing early preeclampsia, and the more elevated they are, the higher the likelihood.

Timing of ischemic insult alters fetal growth trajectory, maternal angiogenic balance, and markers of renal oxidative stress in the pregnant rat

Increased uterine artery resistance and angiogenic imbalance characterized by increased soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased free vascular endothelial growth factor (VEGF) are often associated with placental insufficiency and preeclampsia but not synonymous with hypertension. We hypothesized chronic reductions in utero-placental perfusion (RUPP) for 5 days (d) during either mid- (d12-d17) or late (d14-d19) gestation would have disparate effects on plasma sFlt-1 and VEGF levels and blood pressure. Five days of chronic RUPP was achieved by placement of silver clips on the abdominal aorta and ovarian arteries on either gestational d12 or d14. Arterial pressure was increased (P < 0.05) in RUPP vs. normal pregnant (NP) in both d17 (10%) and d19 (25%) groups, respectively. Circulating free VEGF was decreased (P < 0.05) and sFlt-1:VEGF ratio increased (P < 0.05) after 5 days of RUPP ending on d19 but not d17 compared with NP controls. Angiogenic imbalance, measured by an endothelial tube formation assay, was present in the d19 RUPP but not the d17 RUPP compared with age-matched NP rats. Five days of RUPP from days 14 to 19 decreased fetal and placental weights 10% (P < 0.01) compared with d19 NP controls. After 5 days of RUPP, from days 12 to 17 of pregnancy, fetal weights were 21% lighter (P < 0.01) compared with d17 NP controls, but placental weight was unchanged. These findings suggest that the timing during which placental insufficiency occurs may play an important role in determining the extent of alterations in angiogenic balance, fetal growth restriction, and the severity of placental ischemia-induced hypertension.

Late-onset preeclampsia is associated with an imbalance of angiogenic and anti-angiogenic factors in patients with and without placental lesions consistent with maternal underperfusion

OBJECTIVE

An imbalance between maternal angiogenic/anti-angiogenic factors concentrations has been observed in preeclampsia (PE) and other obstetrical syndromes. However, the frequency of pathologic findings in the placenta and the changes in maternal plasma angiogenic/anti-angiogenic factor concentrations differ between late- and early-onset PE. The aim of this study was to determine if the maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 and 2 (sVEGFR-1 and sVEGFR-2) are different in late-onset PE with and without placental pathologic findings consistent with maternal underperfusion.

STUDY DESIGN

A cross-sectional study was conducted including 64 uncomplicated women and 66 women with late-onset PE (>34 weeks) who had blood samples and placenta available for pathologic examination. Patients with late-onset PE were divided into those with and without placental histologic findings consistent with maternal underperfusion as proposed by the Society for Pediatric Pathology. Maternal plasma concentrations of PlGF, sEng, sVEGFR-1 and sVEGRF-2 were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

1) the prevalence of placental histological findings consistent with maternal underperfusion among women with late-onset PE was higher than that of those with an uncomplicated pregnancy (47% (31/66) vs. 7.8% (5/64), respectively; p < 0.01); 2) patients with late-onset PE and histological findings consistent with maternal underperfusion had a significantly lower median plasma concentration of PlGF, plasma PlGF/sVEGFR-1 ratio and plasma PlGF/sEng ratio than those with late-onset PE without placental underperfusion lesions (each p < 0.05); 3) the most common pathological findings in the placenta of patient with PE were lesions consistent with villous changes (77%, 24/31); and 4) isolated vascular lesions in the placenta were found only in 2 cases (6.5%), and the rest had a combination of villous and vascular lesions.

CONCLUSIONS

Nearly half of the patients with late-onset PE have placental lesions consistent with maternal underperfusion. These lesions are associated with an imbalance in the maternal concentration of angiogenic/anti-angiogenic factors. We propose that there is a link between maternal underperfusion and an anti-angiogenic state characterized by the changes in the concentrations of angiogenic and anti-angiogenic factors in women with late onset PE.

The vascular endothelial growth factor family in adverse pregnancy outcomes

BACKGROUND

Pre-eclampsia, small-for-gestational-age infants, preterm birth and recurrent miscarriage complicate a significant number of pregnancies. The vascular endothelial growth factor (VEGF) family of angiogenic growth factors is implicated in the pathophysiology of these complications. We aimed to elucidate the role of these angiogenic factors in placentation and to evaluate the predictive value of their protein concentrations and genetic variations in pregnancy complications.

METHODS

We performed a systematic search of PubMed, and retrieved original articles. The search included a combination of terms such as VEGF-A, placental growth factor (PlGF), kinase insert domain receptor, fms-like-tyrosine-kinase receptor 1, soluble fms-like-tyrosine-kinase receptor 1, pre-eclampsia, small-for-gestational-age infants, preterm birth, recurrent miscarriage, placenta, prediction and polymorphisms.

RESULTS

This review summarizes the current knowledge of the roles of the VEGF family in early placentation and of the abnormalities in maternal plasma and placental expression of angiogenic proteins in adverse pregnancy outcomes compared with normal pregnancy. PlGF and sFLT-1 in combination with other clinical and biochemical markers in late first or second trimester appear to predict early-onset pre-eclampsia with a high sensitivity and specificity. However, VEGF family proteins do not have sufficient power to accurately predict late-onset pre-eclampsia, small-for-gestational age pregnancies or preterm birth. Functional polymorphisms in these angiogenic genes are implicated in pregnancy complications, but their contribution appears to be minor.

CONCLUSIONS

Although the VEGF family has important roles in normal and complicated pregnancy, the current predictive value of the VEGF family as biomarkers appears to be limited to early-onset pre-eclampsia.

The placenta in preeclampsia

The root cause of preeclampsia is the placenta. Preeclampsia begins to abate with the delivery of the placenta and can occur in the absence of a fetus but with the presence of trophoblast tissue with hydatidiform moles. In view of this, study of the placenta should provide insight into the pathophysiology of preeclampsia. In this presentation we examine placental pathological and pathophysiological changes with preeclampsia and fetal growth restriction (FGR). It would seem that this comparison should be illuminating as both conditions are associated with similarly abnormal placentation yet only in preeclampsia is there a maternal pathophysiological syndrome. Similar insights about early and late onset preeclampsia should also be provided by such information.We report that the placental abnormalities in preeclampsia are what would be predicted in a setting of reduced perfusion and oxidative stress. However, the differences from FGR are inconsistent. The most striking differences between the two conditions are found in areas that have been the least studied. There are differences between the placental findings in early and late onset preeclampsia but whether these are qualitative, indicating different diseases, or simply quantitative differences within the same disease is difficult to determine.We attempt to decipher the true differences, seek an explanation for the disparate results and provide recommendations that we hope may help resolve these issues in future studies.

Dopplerfluxometria de artérias oftálmicas e avaliação da função endotelial nas formas precoce e tardia da pré-eclâmpsia

OBJETIVO: Avaliar possíveis diferenças entre a disfunção endotelial, avaliada pela dilatação fluxo-mediada, e hiperperfusão central, avaliada por dopplerfluxometria da artéria oftálmica, entre pacientes portadoras da forma precoce e tardia da pré-eclâmpsia. MATERIAIS E MÉTODOS: O teste de dilatação fluxo-mediada e a dopplerfluxometria da artéria oftálmica foram obtidos de 81 gestantes, sendo 56 portadoras de pré-eclâmpsia (26 na forma precoce e 30 na forma tardia) e 25 gestantes saudáveis (grupo controle). RESULTADOS: Portadoras de pré-eclâmpsia apresentaram valores menores de dilatação fluxo-mediada quando comparadas ao grupo controle, tanto na forma precoce (7,62 ± 5,42% × 14,12 ± 6,14%; p = 0,02) como na forma tardia (5,83 ± 4,12% × 14,12 ± 6,14%; p = 0,00). Não houve diferença quando foram comparadas as duas formas (7,62 ± 5,42% × 5,83 ± 4,12%; p = 0,09). A dopplerfluxometria da artéria oftálmica apresentou-se significativamente menor nas pacientes portadoras de pré-eclâmpsia quando comparadas ao grupo controle, tanto na forma precoce (0,631 ± 0,024 × 0,737 ± 0,032; p = 0,01) como na forma tardia (0,653 ± 0,019 × 0,737 ± 0,032; p = 0,03). Não houve diferença entre as duas formas de apresentação (0,631 ± 0,024 × 0,653 ± 0,019; p = 0,12). Os resultados basicamente demonstram redução nos valores de dilatação fluxo-mediada e dopplerfluxometria da artéria oftálmica nas formas tardia e precoce da pré-eclâmpsia quando comparadas ao grupo controle, sem, contudo, diferenças significativas entre as duas formas de apresentação da doença. CONCLUSÃO: Os resultados indicam a presença de disfunção endotelial e hiperperfusão central em gestantes com pré-eclâmpsia, tanto na forma precoce como na tardia.

Can placental growth factor in maternal circulation identify fetuses with placental intrauterine growth restriction?

OBJECTIVE

We investigated whether decreased concentrations of placental growth factor (PlGF) in maternal circulation differentiated placental intrauterine growth restriction (IUGR) from constitutionally small fetuses. Excluding congenital syndromes, infection, and aneuploidy, we assumed IUGR with an abnormal placental pathology to be of placental origin.

STUDY DESIGN

The study design included a single site, case-control study of 16 cases (9 placental IUGR, 7 constitutionally small) and 79 normal controls with singleton pregnancies. Plasma PlGF was measured by Triage PlGF immunoassay according to the product insert. A positive PlGF test was defined as a concentration less than the fifth percentile for gestational age for normal pregnancy.

RESULTS

A positive PlGF test was found in 9 of 9 placental IUGR cases, 1 of 7 constitutionally small fetuses, and 4 of 79 controls (P < .0001). PlGF identified placental IUGR from constitutionally small fetuses with 100% sensitivity and 86% specificity (P = .0009).

CONCLUSION

These preliminary data suggest PlGF may identify placental IUGR antenatally.

Screening for pre-eclampsia: a systematic review of tests combining uterine artery Doppler with other markers

AIMS

To perform a systematic review of screening for pre-eclampsia (PE) with the combination of uterine artery Doppler (UAD), maternal history, mean arterial pressure and/or maternal serum markers.

METHODS

We identified eligible studies through a search of Medline, and, for each included study, we assessed the risk of bias and extracted relevant data. We reported the performance of screening tests according to the target population (low- or high-risk), the trimester of screening (first and/or second) and the subset of PE screened for (early and late).

RESULTS

Several tests provided moderate or convincing prediction of early PE, but screening for late PE was poor. Although UAD is more accurate in the second trimester, we found encouraging results for first-trimester screening when it was combined with other markers. Performance of screening was consistently lower in populations with risk factors for PE in the maternal history.

CONCLUSIONS

We present encouraging results for the prediction of early PE, even in the first trimester of pregnancy. The different performance of tests in screening for early vs. late PE, and of low- vs. high-risk populations, supports the concept that PE is a heterogeneous disease.

Placental lesions associated with maternal underperfusion are more frequent in early-onset than in late-onset preeclampsia

OBJECTIVE

Preeclampsia (PE) has been classified into early- and late-onset disease. These two phenotypic variants of PE have been proposed to have a different pathophysiology. However, the gestational age cut-off to define "early" vs. "late" PE has varied among studies. The objective of this investigation was to determine the prevalence of lesions consistent with maternal underperfusion of the placenta in patients with PE as a function of gestational age.

STUDY DESIGN

A nested case-control study of 8307 singleton pregnant women who deliver after 20 weeks of gestation was constructed based on a cohort. Cases were defined as those with PE (n=910); controls were pregnant women who did not have a hypertensive disorder in pregnancy (n=7397). The frequency of maternal underperfusion of the placenta (according to the criteria of the Society for Pediatric Pathology) was compared between the two groups. Logistic regression was used for analysis. Estimated relative risks (RRs) were calculated from odds ratios.

RESULTS

1) The prevalence of lesions consistent with maternal underperfusion was higher in patients with PE than in the control group [43.3% vs. 15.9%, unadjusted odds ratio 4.0 (95% CI 3.5-4.7); P<0.001]; 2) the estimated RR of maternal underperfusion lesions in PE was higher than in the control group [RR=2.8 (95% CI 2.5-3.0)]; 3) the lower the gestational age at delivery, the higher the RR for these lesions; 4) early-onset PE, regardless of the gestational age used to define it (<32, 33, 34, 35 or 37 weeks) had a significantly higher frequency of placental lesions consistent with maternal underperfusion than late-onset PE (P<0.001 for all).

CONCLUSIONS

1) The earlier the gestational age of preeclampsia at delivery, the higher the frequency of placental lesions consistent with maternal underperfusion; 2) our data suggest that demonstrable placental involvement as determined by pathologic examination differs in early- and late-onset preeclampsia; and 3) this phenomenon appears to be a continuum, and we could not identify a clear and unambiguous gestational age at which lesions consistent with underperfusion would not be present.

Threshold of soluble fms-like tyrosine kinase 1/placental growth factor ratio for the imminent onset of preeclampsia

It has not been clarified whether thresholds of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), soluble endoglin, and the sFlt-1/PlGF ratio for the imminent onset of preeclampsia (PE) exist. We hypothesized that onset thresholds for the imminent onset of PE could be determined by the distributions of these 4 markers just after the onset of PE. Study subjects were 51 PE after the onset of PE; 36 of PE, 20 of gestational hypertension, 142 of a small-for-gestational-age infant, and 400 of normal pregnant controls at 19 to 25 and 27 to 31 weeks of gestation in a prospective cohort study. The current data supported our hypothesis that onset thresholds of sFlt-1 and the sFlt-1/PlGF ratio exist. The onset thresholds of the sFlt-1/PlGF at 26 to 31 weeks of gestation were useful for detecting imminent PE with the onset at <36 weeks of gestation, showing sensitivity of 0.36 and a positive likelihood ratio and 95th percent CIs of 38 (11-132); when positive, PE occurred at 2.2±0.6 weeks (range: 1.4-3.0 weeks) after the measurement of the sFlt-1/PlGF ratio. The combination of sFlt-1 at 26 to 31 weeks of gestation, past history of gestational hypertension or PE, prepregnancy body mass index, and mean blood pressure at 16 to 23 weeks of gestation was useful for detecting PE with onset of <36 weeks of gestation, showing sensitivity of 0.82, and a positive likelihood ratio (95% CI) of 42 (20-88). In conclusion, the onset threshold of sFlt-1/PlGF existed and might be useful for detecting the imminent onset of PE.

Increased endoplasmic reticulum stress in decidual tissue from pregnancies complicated by fetal growth restriction with and without pre-eclampsia

OBJECTIVES

Endoplasmic reticulum (ER) stress has been implicated in both pre-eclampsia (PE) and fetal growth restriction (FGR), and is characterised by activation of three signalling branches: 1) PERK-pEIF2α, 2) ATF6 and 3) splicing of XBP1(U) into XBP1(S). To evaluate the contribution of ER stress in the pathogenesis of PE relative to FGR, we compared levels of ER stress markers in decidual tissue from pregnancies complicated by PE and/or FGR.

STUDY DESIGN

Whole-genome transcriptional profiling was performed on decidual tissue from women with PE (n = 13), FGR (n = 9), PE+FGR (n = 24) and controls (n = 58), and used for pathway and targeted transcriptional analyses of ER stress markers. The expression and cellular localisation of ER stress markers was assesses by Western blot and immunofluorescence analyses.

RESULTS

Increased ER stress was observed in FGR and PE+FGR, including both the PERK-pEIF2α and ATF6 signalling branches, whereas ER stress was less evident in isolated PE. However, these cases demonstrated elevated levels of XBP1(U) protein. ATF6 and XBP1 immunoreactivity was detected in most (>80%) extravillous trophoblasts, decidual cells and macrophages. No difference in the proportion of immunopositive cells or staining pattern was observed between study groups.

CONCLUSIONS

Increased PERK-pEIF2α and ATF6 signalling have been associated with decreased cellular proliferation and may contribute to the impaired placental growth characterising pregnancies with FGR and PE+FGR. XBP1(U) has been proposed as a negative regulator of ER stress, and increased levels in PE may reflect a protective mechanism against the detrimental effects of ER stress.

The unique pathophysiology of early-onset severe preeclampsia: role of decidual T regulatory cells

Immunological mechanisms play a pivotal role in the pathophysiology of preeclampsia. T regulatory cells (Treg cells, FoxP3(+)) suppress the cytotoxic T cell (CD8(+)) and natural killer (NK) cell response, thereby promoting immunological tolerance to the fetus. In peripheral blood, Treg cells are elevated during pregnancy, decrease throughout gestation, and are decreased in preeclampsia. To determine their role at the implantation site, we characterized the proportion of decidual Treg and CD8+ cells, and compared these with placental histology, villous sFlt expression, and chorionic trophoblast apoptotic index in normal and preeclamptic pregnancies. Decidua from first (n=5) and second (n=4) trimester terminations and chorioamniotic membranes, containing decidua, from term deliveries (n=14), early-onset (≤ 34 weeks) (n=12), and late-onset (>34 weeks) (n=14) severe preeclampsia were evaluated. Immunohistochemistry for CD3, CD8, and FoxP3 was performed: CD8(+) and FoxP3(+) cells were calculated as a proportion of CD3(+) cells. Placental tissue was evaluated for villous hypermaturity and sFlt staining. Chorioamniotic membranes were evaluated, via TUNEL assay, for chorionic trophoblast apoptosis. Decidual Treg cells were seen to peak in second trimester and decrease with advancing gestational age and were lower in early-onset (0.46%) compared with late-onset severe preeclampsia (3.34%) and term pregnancies (5.21%). The proportion of CD8(+) cells was higher in cases of severe preeclampsia. Early-onset severe preeclamptic cases had the highest sFlt score, placental insufficiency score, and apoptotic index. Our data suggest that early-onset severe preeclampsia has a unique pathophysiology involving defective immunoregulatory pathways, potentially causing vascular and trophoblast damage at the implantation site.

Angiogenic factors and preeclampsia

Preeclampsia, a hypertensive disorder peculiar to pregnancy, is a systemic syndrome that appears to originate in the placenta and is characterized by widespread maternal endothelial dysfunction. Until recently, the molecular pathogenesis of phenotypic preeclampsia was largely unknown, but recent observations support the hypothesis that altered expression of placental anti-angiogenic factors are responsible for the clinical manifestations of the disease. Soluble Flt1 and soluble endoglin, secreted by the placenta, are increased in the maternal circulation weeks before the onset of preeclampsia. These anti-angiogenic factors produce systemic endothelial dysfunction, resulting in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, and as of 2011 the role of angiogenic proteins in early placental vascular development was starting to be explored. The data linking angiogenic factors to preeclampsia have exciting clinical implications, and likely will transform the detection and treatment of preeclampsia.

Expression of placental FLT1 transcript variants relates to both gestational hypertensive disease and fetal growth

The recent discovery of additional alternative spliced FLT1 transcripts encoding novel soluble (s)FLT1 protein isoforms complicates both the predictive value and functional implications of sFLT1 in preeclampsia. We investigated FLT1 expression levels and splicing patterns in placentas of normotensive and preeclamptic women, and established the tissue specificity of all FLT1 transcript variants. mRNA levels of sFLT1 splice variants were determined by real-time polymerase chain reaction in 21 normal human tissues and placental biopsies from 91 normotensive and 55 preeclamptic women. Cellular localization of placental FLT1 expression was established by RNA in situ hybridization. Of all tissues investigated, placenta has by far the highest FLT1 mRNA expression level, mainly localized in the syncytiotrophoblast layer. More than 80% of placental transcripts correspond to sFLT1_v2. Compared with normotensive placenta, preeclamptic placenta has ≈3-fold higher expression of all FLT1 transcript variants (P<0.001), with a slight shift in favor of sFLT1_v1. Although to a lesser degree, transcript levels are also increased in placenta from normotensive women that deliver a small for gestational age neonate. We conclude that sFLT isoform-specific assays could potentially improve the accuracy of current sFLT1 assays for the prediction of preeclampsia. However, placental FLT1 transcript levels are increased not only in preeclampsia but also in normotensive pregnancy with a small for gestational age fetus. This may indicate a common pathway involved in the development of both conditions but complicates the use of circulating sFLT1 protein levels for the prediction or diagnosis of preeclampsia alone.

Intrauterine growth restriction: new concepts in antenatal surveillance, diagnosis, and management

Intrauterine growth restriction (IUGR) remains one of the main challenges in maternity care. Improvements have to start from a better definition of IUGR, applying the concept of the fetal growth potential. Customized standards for fetal growth and birthweight improve the detection of IUGR by better distinction between physiological and pathological smallness and have led to internationally applicable norms. Such developments have resulted in new insights in the assessment of risk and surveillance during pregnancy. Serial fundal height measurement plotted on customized charts is a useful screening tool, whereas fetal biometry and Doppler flow are the mainstay for investigation and diagnosis of IUGR. Appropriate protocols based on available evidence as well as individualized clinical assessment are essential to ensure good management and timely delivery.

Angiogenic factors in maternal circulation and the risk of severe fetal growth restriction

Maternal angiogenic factors (placental growth factor, soluble fms-like tyrosine kinase 1 (Flt-1), and soluble endoglin) may be associated with fetal growth restriction, and the associations may differ according to stage of pregnancy. Among children born to pregnant women without preeclampsia in Norway between 1992 and 1994, 217 singletons with severe growth restriction (small for gestational age (SGA), <2.5th percentile) were compared with 378 singleton controls. For each angiogenic factor, SGA risk was related to concentrations in maternal serum collected in the first 2 trimesters, by using women with a serum concentration in the middle third at both samplings as reference. A low placental growth factor (lowest third) at both samplings was associated with high risk of SGA (odds ratio=3.8, 95% confidence interval: 1.6, 8.8). An increase from the lowest to the highest third of soluble Flt-1 was associated with high SGA risk (odds ratio=6.2, 95% confidence interval: 2.4, 16.1). Women with high soluble endoglin (highest third) at the second sampling had approximately a 3.5-fold increased risk of SGA. Low maternal soluble Flt-1 in early pregnancy followed by a strong subsequent increase in soluble Flt-1 and soluble endoglin was associated with a particularly high risk of severe fetal growth restriction.

Polymorphisms in maternal and fetal genes encoding for proteins involved in extracellular matrix metabolism alter the risk for small-for-gestational-age

OBJECTIVE

To examine the association between maternal and fetal genetic variants and small-for-gestational-age (SGA).

METHODS

A case-control study was conducted in patients with SGA neonates (530 maternal and 436 fetal) and controls (599 maternal and 628 fetal); 190 candidate genes and 775 SNPs were studied. Single-locus, multi-locus and haplotype association analyses were performed on maternal and fetal data with logistic regression, multifactor dimensionality reduction (MDR) analysis, and haplotype-based association with 2 and 3 marker sliding windows, respectively. Ingenuity pathway analysis (IPA) software was used to assess pathways that associate with SGA.

RESULTS

The most significant single-locus association in maternal data was with a SNP in tissue inhibitor of metalloproteinase 2 (TIMP2) (rs2277698 OR = 1.71, 95% CI [1.26-2.32], p = 0.0006) while in the fetus it was with a SNP in fibronectin 1 isoform 3 preproprotein (FN1) (rs3796123, OR = 1.46, 95% CI [1.20-1.78], p = 0.0001). Both SNPs were adjusted for potential confounders (maternal body mass index and fetal sex). Haplotype analyses resulted in associations in α 1 type I collagen preproprotein (COL1A1, rs1007086-rs2141279-rs17639446, global p = 0.006) in mothers and FN1 (rs2304573-rs1250204-rs1250215, global p = 0.045) in fetuses. Multi-locus analyses with MDR identified a two SNP model with maternal variants collagen type V α 2 (COL5A2) and plasminogen activator urokinase (PLAU) predicting SGA outcome correctly 59% of the time (p = 0.035).

CONCLUSIONS

Genetic variants in extracellular matrix-related genes showed significant single-locus association with SGA. These data are consistent with other studies that have observed elevated circulating fibronectin concentrations in association with increased risk of SGA. The present study supports the hypothesis that DNA variants can partially explain the risk of SGA in a cohort of Hispanic women.

Circulating angiogenic and antiangiogenic factors in women with eclampsia

OBJECTIVE

The objective of the study was to determine whether eclampsia has a different circulating profile of angiogenic (placental growth factor [PlGF]) and antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 [sVEGFR-1] and soluble endoglin [sEng]) from severe preeclampsia.

STUDY DESIGN

This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 40); (2) severe preeclampsia (n = 40); and (3) eclampsia (n = 20). Maternal serum PlGF, sVEGFR-1, and sEng concentrations were determined using an enzyme-linked immunosorbent assay.

RESULTS

The study results included the following: (1) the median concentration of sVEGFR-1 and sEng was higher and of PlGF was lower in severe preeclampsia or eclampsia than in normal pregnancy (P < .001 for all); and (2) the median concentrations of these 3 analytes did not differ significantly between patients with severe preeclampsia and those with eclampsia.

CONCLUSION

Eclampsia is associated with higher maternal circulating concentrations of sVEGFR-1 and sEng and lower concentrations of PlGF than normal pregnancy but with similar concentrations to severe preeclampsia. These findings suggest that eclampsia shares a common pathogenic pathway as severe preeclampsia.

Are early and late preeclampsia distinct subclasses of the disease--what does the placenta reveal?

OBJECTIVE

To compare histopathological differences in placentas from early- and late-onset preeclampsia, as well as late-onset preeclampsia and normal term deliveries.

METHODS

This prospective study was performed at Tygerberg Hospital, a secondary and tertiary referral center in South Africa. Placentas from 100 women, 25 each with early and late-onset preeclampsia, and an equal number of controls matched for gestational age, underwent routine preparation and were evaluated independently by two pathologists in a strictly predetermined, standardized manner.

RESULTS

Compared to late preeclampsia, placentas in the early preeclampsia group were smaller (p < 0.01), had more infarction (odds ratio [OR] = 4.03, 95% confidence interval [CI] = 1.2-13.5) and inappropriate maturation (OR = 16.62, 95% CI = 4.1-68.0). Placentas from the late-onset preeclampsia group showed increased decidual arteriopathy (OR = 5.09, 95% CI = 1.45-17.92) and abruptio placentae (OR = 5.41, 95% CI = 1.01-28.79) compared to controls.

CONCLUSIONS

The early- and late-onset preeclampsia placentas showed clear histopathological differences, whereas late-onset preeclampsia and normal term placentas differed less. These findings support the contention that early- and late-onset preeclampsia are different subclasses of disease.

Vascular Dysfunction in Women With a History of Preeclampsia and Intrauterine Growth Restriction

Background—

Women with a history of placental disease are at increased risk for the future development of vascular disease. It is unknown whether preexisting endothelial dysfunction underlies both the predisposition to placental disease and the later development of vascular disease. The aim of this study was to assess vascular function in postpartum women and to determine whether differences emerged depending on the presentation of placental disease.

Methods and Results—

Women with a history of early-onset preeclampsia (n=15), late-onset preeclampsia (n=9), intrauterine growth restriction without preeclampsia (n=9), and prior normal pregnancy (n=16) were studied 6 to 24 months postpartum. Flow-mediated vasodilatation and flow-independent (glyceryl trinitrate–induced) vasodilatation were studied through the use of high-resolution vascular ultrasound examination of the brachial artery. Arterial stiffness was assessed by pulse-wave analysis (augmentation index). Laboratory assessment included circulating angiogenic factors (vascular endothelial growth factor, soluble fms-like tyrosine kinase 1, placental growth factor, and soluble endoglin). Flow-mediated vasodilatation was significantly reduced in women with previous early-onset preeclampsia and intrauterine growth restriction compared with women with previous late-onset preeclampsia and control subjects (3.2±2.7% and 2.1±1.2% versus 7.9±3.8% and 9.1±3.5%, respectively; P <0.0001). Flow-independent vasodilatation was similar among all groups. Similarly, the radial augmentation index was significantly increased among women with previous early-onset preeclampsia and intrauterine growth restriction, but not among late preeclamptic women and control subjects ( P =0.0105). Circulating angiogenic factors were similar in all groups.

Conclusion—

Only women with a history of early-onset preeclampsia or intrauterine growth restriction without preeclampsia exhibit impaired vascular function, which might explain their predisposition to placental disease and their higher risk of future vascular disease.

Low neonatal birth weight as a possible predictive factor for the onset of postpartum eclampsia

OBJECTIVE

To report about a case of complicated late postpartum eclampsia where neonatal low birth weight could be considered a predictive factor of placental sufferance.

METHODS

A 25-year-old woman, without medical or familiar history for hypertension or cerebrovascular diseases, underwent a normal spontaneous delivery with neonatal birth weight of 2340 g (9th percentile). Eight days later the patient presented sudden headache and generalized tonic-clonic seizures.

RESULTS

Blood hypertension and alterations in laboratory studies were detected; a diagnosis of late postpartum eclampsia was made. A CT scan showed subarachnoid hemorrhage (Hunt and hess grade I, Fisher grade III). Serial cerebral angiograms did not show any intracranial vascular malformations; epilepsy and hypertension were successfully medically treated; and a repeat CT examination showed the gradual resolution of subarachnoid hemorrhage. Headache progressively disappeared.

CONCLUSIONS

Low neonatal birth weight could be linked to placental dysfunction and considered as a predictive factor for the onset of postpartum preeclampsia/eclampsia. We recommend a careful clinical and laboratory management of puerperium up to the first month postpartum, in particular in cases of "sine causa" neonatal low birth weight.

Microbial invasion of the amniotic cavity in preeclampsia as assessed by cultivation and sequence-based methods

OBJECTIVE

Infection has been implicated in the pathogenesis of preeclampsia, yet the association between microbial invasion of the amniotic cavity (MIAC) and preeclampsia has not been determined. The aim of this study was to determine the prevalence, and microbial diversity associated with MIAC, as well as the nature of the host response to MIAC in patients with preeclampsia.

METHOD OF STUDY

Amniotic fluid (AF) from 62 subjects with preeclampsia, not in labor, was analyzed with both cultivation and molecular methods. Broad-range and group-specific PCR assays targeting small subunit ribosomal DNA, or other gene sequences, from bacteria, fungi and archaea were used. Results were correlated with measurements of host inflammatory response, including AF white blood cell count and AF concentrations of glucose, interleukin-6 (IL-6) and MMP-8.

RESULTS

1) The rate of MIAC in preeclampsia was 1.6% (1/62) based on cultivation techniques, 8% (5/62) based on PCR, and 9.6% (6/62) based on the combined results of both methods; 2) among the six patients diagnosed with MIAC, three had a positive PCR for Sneathia/Leptotrichia spp.; and 3) patients with MIAC were more likely to have evidence of an inflammatory response in the amniotic cavity than those without MIAC, as determined by a higher median AF IL-6 [1.65 ng/mL interquartile range (IQR): 0.35-4.62 vs. 0.22 ng/mL IQR: 0.12-0.51; P=0.002).

CONCLUSION

The prevalence of MIAC in preeclampsia is low, suggesting that intra-amniotic infection plays only a limited role in preeclampsia. However, the unexpectedly high number of positive AF specimens for Sneathia/Leptotrichia warrants further investigation.

Relation between maternal angiogenic factors and utero-placental resistance in normal first- and second-trimester pregnancies

OBJECTIVE

Soluble endoglin (sEng) is a novel antiangiogenic protein and elevated sEng concentrations in maternal circulation are closely related to preeclampsia and HELLP syndrome. As the perfusion of the uterine arteries as well as the dynamics of angiogenic factors between first and second trimester have prognostic value regarding pregnancy outcome, it was the aim of this study to investigate the relation between maternal angiogenic factors and uterine Doppler parameters.

STUDY DESIGN

The longitudinal study includes 50 normal pregnancies. Pulsatility index (PI) of the uterine arteries was detected by Doppler ultrasound in first and second trimester. In parallel, maternal sEng and soluble fms-like tyrosine kinase 1 (sFlt1) concentration was measured using ELISA.

RESULTS

In the first trimester, the sEng concentrations were 4.92 ± 1.36 ng/mL and the uterine PI was 1.14 ± 0.28. In the second trimester, the maternal sEng concentration decreased significantly to 3.99 ± 0.63 ng/mL (p < 0.05) which was associated by a decrease of the uterine PI to 0.78 ± 0.15 (p < 0.001). Soluble fms-like tyrosine kinase 1 concentrations did not differ significantly between first and second trimester (423 ± 333 vs. 444 ± 291 pg/mL). There was a significant negative correlation between sEng and uterine resistance in the second trimester (r = -0.416; p < 0.001).

CONCLUSIONS

In normal pregnancy, parallel to the fall of utero-placental resistance, there is a physiological decline of the maternal sEng concentration between first and second trimester. In second trimester, there is a negative correlation between sEng and uterine Doppler parameters.

Serum and plasma determination of angiogenic and anti-angiogenic factors yield different results: the need for standardization in clinical practice

OBJECTIVE

The importance of an anti-angiogenic state as a mechanism of disease in preeclampsia is now recognized. Assays for the determination of concentrations of soluble vascular endothelial growth factor receptor (sVEGFR)-1, sVEGFR-2, placental growth factor (PlGF) and soluble endoglin (sEng) have been developed for research and clinical laboratories. A key question is whether these factors should be measured in plasma or serum. The purpose of this study was to determine if there are differences in the concentrations of these analytes between plasma and serum in normal pregnancy and in preeclampsia.

METHODS

Samples of maternal blood were obtained by venipuncture and collected in EDTA (lavender top) and serum collection tubes (red top). A standard laboratory procedure was implemented for the centrifugation, aliquoting and storage of samples. Plasma and serum from 70 women with normal pregnancies and 34 patients with preeclampsia were assayed for sVEGFR-1, sVEGFR-2, PlGF and sEng by ELISA. Nonparametric paired tests were used for analyses.

RESULTS

A significant difference between plasma and serum concentration was observed for sVEGFR-1 and sVEGFR-2 in normal pregnancy, and for sVEGFR-1, sVEGFR-2, PlGF and sEng in women with preeclampsia.

CONCLUSION

The concentrations of sVEGFR-1, sVEGFR-2, PlGF and sEng when measured in maternal plasma and in serum are different. Therefore, the matrix used for the assay (serum versus plasma) needs to be considered when selecting thresholds for predictive studies and interpreting the growing body of literature on this subject.

Could alterations in maternal plasma visfatin concentration participate in the phenotype definition of preeclampsia and SGA?

OBJECTIVE

Women with preeclampsia and those who delivered a small-for-gestational-age (SGA) neonate share several mechanisms of disease, including chronic uteroplacental ischemia and failure of physiologic transformation of the spiral arteries. However, the clinical manifestation of these obstetrical syndromes is remarkably different. It has been proposed that an altered maternal metabolic state, as well as a unique circulating cytokines milieu, predispose women to develop either preeclampsia or SGA. Compelling evidence suggests that adipose tissue orchestrates both metabolic pathways and immunological responses via the production of adipokines. Visfatin is a novel adipocytokine with metabolic and immunomodulating properties. The objective of this study was to determine whether preeclampsia and SGA are associated with alterations in maternal circulating visfatin concentrations.

METHODS

This cross-sectional study included pregnant women in the following groups: (1) normal pregnancy (n = 158); (2) patients with preeclampsia (n = 43) of which 32 had an AGA and 11 had an SGA neonate; (3) patients without preeclampsia who delivered an SGA neonate (n = 55). Maternal plasma visfatin concentrations were measured by ELISA. Nonparametric tests and multiple linear regression analysis were used.

RESULTS

(1) Women who delivered an SGA neonate had a higher median maternal plasma visfatin concentration than those with a normal pregnancy (20.0 ng/ml, interquartile range: 17.2-24.6 vs. 15.2 ng/ml, 12.1-19.2, respectively; P < 0.001) and than those with preeclampsia (14.5 ng/ml, 12.5-18.7; P < 0.001); (2) the median maternal plasma visfatin concentration did not differ significantly between patients with preeclampsia and those with a normal pregnancy (P = 0.8); (3) among patients with preeclampsia, there was no significant difference in the median maternal plasma visfatin concentration between those with or without an SGA neonate (P = 0.5); (4) in a linear regression model, delivery of an SGA neonate and pregestational body mass index were independently associated with increased visfatin concentration after adjustment for confounding factors (maternal age, smoking, gestational age at blood collection and the presence of preeclampsia or SGA).

CONCLUSION

(1) Patients with SGA, but not those with preeclampsia, had a higher maternal plasma visfatin concentration than those with a normal pregnancy; (2) this finding suggests differential involvement of visfatin in SGA and preeclampsia; (3) we propose that changes in circulating maternal visfatin concentration may be implicated in the phenotypic definitions and distinction of preeclampsia and SGA.

Angiogenic imbalances: the obstetric perspective

Clinical and experimental evidence indicates that angiogenic imbalances may participate in the mechanisms of disease of several pregnancy complications, some of which may be life threatening. This article reviews current evidence in support of this view and the possibility that the fetus may play a central role in these imbalances; it also reviews recent experimental observations that modulation of angiogenic imbalances during pregnancy may have prophylactic and/or therapeutic value.

Preeclampsia and pregnancies with small-for-gestational age neonates have different profiles of complement split products

OBJECTIVE

The activation of the complement system results in the generation of split products with pro-inflammatory properties. The objective of this study was to determine whether preeclampsia and small-for-gestational age (SGA) are associated with changes in the maternal plasma concentrations of anaphylatoxins C3a, C4a and C5a.

METHODS

A cross-sectional study was conducted in the following groups: (a) normal pregnant women (n = 134); (b) women who delivered an SGA neonate (n = 53); (c) preeclampsia with (n = 52) and without SGA (n = 54). Maternal plasma anaphylatoxin concentrations were determined by enzyme-linked immunoassay.

RESULTS

(1) Women with preeclampsia with or without SGA had a significantly higher median plasma C5a concentration than that of normal pregnant women and those with SGA alone (all P < 0.01); (2) women with SGA alone did not have an increase in plasma C5a concentration; (3) in contrast, the median maternal plasma concentration of C4a was lower in women with preeclampsia and SGA than that of those with a normal pregnancy (P = 0.001); (4) no changes in C3a were observed among the study groups.

CONCLUSION

Preeclampsia is associated with increased plasma concentration of C5a, regardless of the presence or absence of an SGA fetus. In contrast, there was no difference in the plasma C3a, C4a and C5a concentration in patients with SGA.

Defining normal and abnormal fetal growth: promises and challenges

Normal fetal growth is a critical component of a healthy pregnancy and influences the long-term health of the offspring. However, defining normal and abnormal fetal growth has been a long-standing challenge in clinical practice and research. We review various references and standards that are used widely to evaluate fetal growth and discuss common pitfalls of current definitions of abnormal fetal growth. Pros and cons of different approaches to customize fetal growth standards are described. We further discuss recent advances toward an integrated definition for fetal growth restriction. Such a definition may incorporate fetal size with the status of placental health that is measured by maternal and fetal Doppler velocimetry and biomarkers, biophysical findings, and genetics. Although the concept of an integrated definition appears promising, further development and testing are required. An improved definition of abnormal fetal growth should benefit both research and clinical practice.

Leukocytes of pregnant women with small-for-gestational age neonates have a different phenotypic and metabolic activity from those of women with preeclampsia

OBJECTIVE

Preeclampsia and pregnancies complicated by small-for-gestational age (SGA) neonates share several underlying mechanisms of disease. However, while an exaggerated systemic maternal inflammatory response is regarded as one of the hallmarks of the pathogenesis of preeclampsia, the presence of a similar systemic intra-vascular inflammation in mothers of SGA neonates without hypertension is controversial. The aim of this study was to determine phenotypic and metabolic changes in granulocytes and monocytes of women who develop preeclampsia and those who deliver an SGA neonate, compared to normal pregnant women.

METHODS

This cross-sectional study included patients with a normal pregnancy (n = 33), preeclampsia (n = 33), and an SGA without preeclampsia (n = 33), matched for gestational age at blood sample collection. Granulocyte and monocyte phenotypes were determined by flow cytometry, using monoclonal antibodies against selective cluster of differentiation (CD) antigens. The panel of antibodies included the following: CD11b, CD14, CD16, CD18, CD49d, CD62L, CD64, CD66b, and HLA-DR. Intracellular reactive oxygen species (iROS) were assessed at the basal state and after stimulation (oxidative burst). Results were reported as mean channel brightness (MCB) or intensity of detected fluorescence. Analysis was conducted with non-parametric statistics. A p-value < 0.01 was considered statistically significant.

RESULTS

(1) Women who delivered an SGA neonate had a higher MCB of CD11b in granulocytes and monocytes than those with a normal pregnancy (p < 0.001 for both); (2) patients with preeclampsia had a lower median MCB of CD62L in granulocytes (p = 0.006) and a higher median basal iROS and oxidative burst in monocytes than women with an SGA neonate (p = 0.003 and p = 0.002, respectively).

CONCLUSION

Pregnancies complicated by the delivery of an SGA neonate are characterized by a higher activation of maternal peripheral leukocytes than in normal pregnancies, but lower than in pregnancies complicated by preeclampsia.

Hypertensive disorders in pregnancy: screening by biophysical and biochemical markers at 11-13 weeks

OBJECTIVE

To examine the performance of screening for pre-eclampsia (PE) and gestational hypertension (GH) by a combination of maternal factors and various biophysical and biochemical markers at 11-13 weeks' gestation.

METHODS

This was a case-control study of 26 cases of early PE, 90 of late PE, 85 of GH and 201 unaffected controls. Maternal history was recorded, the uterine artery with the lowest pulsatility index (L-PI) and mean arterial pressure (MAP) were measured and stored plasma and serum were analyzed for placental growth factor (PlGF), inhibin-A, activin-A, tumor necrosis factor receptor-1, matrix metalloproteinase-9, pentraxin-3 and P-selectin.

RESULTS

Multivariate logistic regression analysis demonstrated that significant prediction for early PE was provided by maternal factors, MAP, uterine artery L-PI and serum PlGF. Significant prediction of late PE was provided by maternal factors, MAP, uterine artery L-PI, PlGF, activin-A and P-selectin. For GH significant prediction was provided by maternal factors, MAP, uterine artery L-PI and activin-A. In screening by a combination of maternal factors, biophysical and biochemical markers the estimated detection rates, at a 5% false-positive rate, were 88.5% (95% CI, 69.8-97.4%) for early PE, 46.7% (95% CI, 36.1-57.5%) for late PE and 35.3% (95% CI, 25.2-46.4%) for GH.

CONCLUSION

Combined biophysical and biochemical testing at 11-13 weeks could effectively identify women at high risk for subsequent development of hypertensive disorders in pregnancy.

The prognostic role of uterine artery Doppler investigation in patients with severe early-onset preeclampsia

OBJECTIVE

The purpose of this study was to evaluate the prediction capacity of uterine artery Doppler investigation for maternal and neonatal complications in women who are admitted with severe early-onset preeclampsia.

STUDY DESIGN

A uterine artery Doppler examination was performed at admission for patients with severe early-onset (<34 weeks of gestation) preeclampsia. The maternal and neonatal outcome of women with abnormal uterine Doppler results was compared with those with normal Doppler results.

RESULTS

One hundred twenty patients were included. In 53% of them, uterine Doppler results were abnormal. This group had a lower gestational age at delivery (30.2 vs 32.7 weeks; P < .001) and a higher proportion of small-for-gestational age infants (87.5% vs 67.9%; P = .009). Neonatal (40.6% vs 14.3%; P = .01) and maternal (28.1% vs 5.4%; P = .001) complications were more common in the abnormal uterine Doppler group.

CONCLUSION

Women with severe early-onset preeclampsia are at higher risk of maternal and neonatal complications if abnormal uterine blood flow is present.