L. F. Gonçalves

Plasma soluble vascular endothelial growth factor receptor-1 concentration is elevated prior to the clinical diagnosis of pre-eclampsia

Objective: Accumulating evidence suggests that the balance between vascular endothelial growth factor (VEGF), placental growth factor (PlGF), and their receptors is important for effective vasculogenesis, angiogenesis, and placental development. Recently, the soluble form of VEGFR-1 (sVEGFR-1), an antagonist to VEGF and PlGF, has been implicated in the pathophysiology of pre-eclampsia. Plasma sVEGFR-1 concentration is elevated in pre-eclampsia at the time of clinical diagnosis and correlates with the severity of the disease. The purpose of this study was to determine whether the concentrations of sVEGFR-1 in plasma of pre-eclamptic patients change prior to the clinical manifestations of the disease. Methods: A longitudinal case-control study was conducted in normal pregnant women (n = 44) and patients with pre-eclampsia (n = 44). Blood sampling was performed at six intervals: (1) 7–16 weeks; (2) 16–24 weeks; (3) 24–28 weeks; (4) 28–32 weeks; (5) 32–36 weeks; and (6) more than 37 weeks of gestation. To examine the relationship between plasma sVEGFR-1 concentration and interval to clinical diagnosis of pre-eclampsia, plasma samples of pre-eclamptic patients at different gestational ages were stratified according to the interval from blood sampling to clinical development of the disease into five groups: (1) at clinical manifestation; (2) 2–5 weeks; (3) 6–10 weeks; (4) 11–16 weeks; and (5) 17–25 weeks before clinical manifestations. Plasma concentrations of sVEGFR-1 were determined by enzyme-linked immunoassay. Parametric statistics and repeated measure procedures were used for the analysis. Results: The mean plasma sVEGFR-1 concentration in pre-eclamptic patients before the clinical manifestation of the disease was significantly higher than in normal pregnant women at 24–28, 28–32, and 32–37 weeks of gestation (p = 0.02, p < 0.001, and p < 0.001, respectively). In contrast, no significant differences in the mean plasma sVEGFR-1 concentration between patients with pre-eclampsia and normal pregnant women were observed both at 7–16 weeks and 16–24 weeks of gestation (p = 0.1 and p = 0.9). Similarly, the mean plasma sVEGFR-1 concentration was significantly higher in pre-eclamptic patients than in normal pregnant women at clinical manifestation, at 2–5 weeks (mean 3.8 weeks), and at 6–10 weeks (mean 8.2 weeks) prior to the development of clinical pre-eclampsia (p < 0.001, p < 0.001, and p = 0.002, respectively). Among patients with early-onset pre-eclampsia (defined as gestational age of 34 weeks or less), the mean plasma sVEGFR-1 concentration was significantly higher in pre-eclampsia (before clinical diagnosis) than in normal pregnant women at 24–28 (mean 26.4) weeks of gestation (p = 0.008). In contrast, among patients with the late-onset disease (defined as gestational age of more than 34 weeks), plasma sVEGFR-1 concentration in pre-clinical pre-eclampsia was significantly higher than in normal pregnant women at 28–32 (mean 30.2) weeks of gestation (p < 0.001). Conclusions: Plasma sVEGFR-1 concentration is elevated in pre-eclampsia prior to the clinical diagnosis of the disease. This elevation began 6–10 weeks prior to the clinical manifestations, and the increase was more pronounced at 2–5 weeks before the diagnosis, as well as at clinical presentation. Furthermore, in early-onset pre-eclampsia, plasma concentration of sVEGFR-1 is elevated earlier than the late-onset disease.

Ultrasonographic examination of the uterine cervix is better than cervical digital examination as a predictor of the likelihood of premature delivery in patients with preterm labor and intact membranes

OBJECTIVE The purpose of this study was to compare the diagnostic performance of ultrasonographic and digital examination of the cervix in the prediction of preterm delivery in patients presenting with preterm labor and intact membranes. STUDY DESIGN Endovaginal ultrasonography was performed in 59 patients admitted with preterm labor (20 to 35 weeks) and cervical dilatation of < 3 cm. Cervical parameters evaluated included endocervical length, the presence of funneling, funnel length, funnel width, cervical index ([Funnel length + 1]/Endocervical length), and cervical dilatation and effacement as determined by digital examination. Outcome variables were the occurrence of preterm delivery (< 36 weeks) and the admission-to-delivery interval. RESULTS The prevalence of preterm delivery was 37.3% (22/59). Receiver-operator characteristic curve and logistic regression analyses indicated a significant relationship between the occurrence of preterm delivery and ultrasonographic cervical parameters (p < 0.005 for each) but not with the results of digital examination of the cervix. Survival analysis demonstrated a shorter admission-to-delivery interval for patients with an abnormal cervical index or endocervical length (p < 0.005 for each). CONCLUSIONS Endovaginal ultrasonographic examination of the uterine cervix is more accurate than digital examination of the cervix in the assessment of the risk for preterm delivery in patients with preterm labor and intact membranes.

The maternal plasma soluble vascular endothelial growth factor receptor-1 concentration is elevated in SGA and the magnitude of the increase relates to Doppler abnormalities in the maternal and fetal circulation

Objectives. The soluble form of vascular endothelial growth factor receptor-1 (sVEGFR-1), an antagonist to vascular endothelial growth factor and placental growth factor, has been implicated in the pathophysiology of preeclampsia. Preeclampsia and pregnancy complicated with small for gestational age (SGA) fetuses share some pathophysiologic derangements, such as failure of physiologic transformation of the spiral arteries, endothelial cell dysfunction, and leukocyte activation. The objectives of this study were to: (1) determine whether plasma concentrations of sVEGFR-1 in mothers with SGA fetuses without preeclampsia at the time of diagnosis are different from those in patients with preeclampsia or normal pregnant women, and (2) examine the relationship between plasma concentrations of sVEGFR-1 and Doppler velocimetry in uterine and umbilical arteries in patients with preeclampsia and those with SGA. Study design. A cross-sectional study was conducted to determine the concentrations of the soluble form of VEGFR-1 in plasma obtained from normal pregnant women (n = 135), women with SGA fetuses (n = 53), and patients with preeclampsia (n = 112). Patients with SGA fetuses and those with preeclampsia were sub-classified according to the results of uterine and umbilical artery Doppler velocimetry examinations. Plasma concentrations of sVEGFR-1 were determined by an ELISA. Since these concentrations change with gestational age, differences among various subgroups were statistically estimated with the delta value, defined as the difference between the observed and expected plasma sVEGFR-1 concentration. The expected values were derived from regression analysis of plasma sVEGFR-1 concentrations in normal pregnancy. Regression analysis and univariate and multivariate analysis were employed. Results. (1) Mothers with SGA fetuses had a mean plasma concentration of sVEGFR-1 higher than normal pregnant women (p < 0.001), but lower than patients with preeclampsia (p < 0.001). (2) Among patients with SGA fetuses, only those with abnormal uterine artery Doppler velocimetry had a mean plasma sVEGFR-1 concentration significantly higher than normal pregnant women (p < 0.001). (3) Among mothers with SGA fetuses in whom Doppler velocimetry was performed (n = 41), those with abnormalities in both the uterine and umbilical artery velocimetry had the highest mean delta of sVEGFR-1 plasma concentration (mean ± standard deviation (SD): 0.69 ± 0.29). Conversely, patients who had normal Doppler velocimetry in both uterine and umbilical arteries had the lowest mean delta (mean ± SD: 0.09 ± 0.29) of sVEGFR-1 plasma concentrations (ANOVA; p < 0.001). (4) Among patients with preeclampsia in whom Doppler velocimetry was performed (n = 69), those with abnormalities in both the uterine and umbilical artery velocimetry had the highest mean delta sVEGFR-1 plasma concentration (mean ± SD: 1.01 ± 0.22) among all groups classified (ANOVA; p < 0.001). (5) Among patients with SGA and those with preeclampsia, there was a relationship (Chi-square for trend p < 0.001 for both) between the severity of Doppler velocimetry abnormalities and the proportion of patients who had high delta sVEGFR-1 plasma concentrations (defined as a concentration two standard deviations (2SD) above the mean delta of normal pregnant women). (6) Multiple regression analysis suggested that the diagnostic category (e.g., SGA or preeclampsia), Doppler abnormalities, and gestational age at blood sampling were associated with an increase in plasma sVEGFR-1 concentrations (p < 0.001). Conclusions. These observations provide support for the participation of the soluble receptor of vascular endothelial growth factor in the pathophysiology of SGA with abnormal uterine artery Doppler velocimetry and preeclampsia. An excess of sVEGFR-1 is released into the maternal circulation of patients with preeclampsia and those with SGA fetuses, as abnormalities of impedance to blood flow involve uterine and umbilical circulation.

Evidence supporting that the excess of the sVEGFR-1 concentration in maternal plasma in preeclampsia has a uterine origin.

Background. Preeclampsia has been considered an anti-angiogenic state. Two factors have been implicated in the genesis of this state: soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and placental growth factor (PlGF). Indeed, the concentrations of PlGF, an angiogenic factor, are lower in preeclampsia than in normal pregnancy, while the opposite is the case for the anti-angiogenic factor, sVEGFR-1. The source of the excess sVEGFR-1 has not yet been determined. Since the placenta could be a source of sVEGFR-1, we conducted a study to determine whether there is a gradient in the plasma concentration of sVEGFR-1 and PlGF between the uterine vein and the antecubital vein in both patients with preeclampsia and normal pregnant women. Methods. A cross-sectional study was performed to determine the plasma concentrations of sVEGFR-1 and PlGF in the uterine and antecubital vein of patients with preeclampsia (n = 9) and normal pregnant women at term (n = 9). Plasma samples were collected from antecubital and uterine veins at the time of cesarean section. The concentrations of sVEGFR-1 and PlGF were determined using specific enzyme-linked immunoassays. The differences of plasma concentrations of sVEGFR-1 and PlGF between uterine and antecubital veins in both groups were compared by paired t-tests. Results. Patients with preeclampsia had a significantly higher mean plasma concentration of sVEGFR-1 in the uterine vein than in the antecubital vein (uterine vein: mean 13,675 ± 5,684 pg/ml vs. antecubital vein: mean 10,234 ± 4,700 pg/ml; paired t-tests, p = 0.04). In contrast, among normal pregnant women at term, there was no significant difference in plasma concentrations of sVEGFR-1 between the uterine and antecubital veins (uterine vein: mean 1,918 ± 665 pg/ml vs. antecubital vein: mean 1,750 ± 475 pg/ml; paired t-tests, p = 0.1). The mean plasma concentration of sVEGFR-1, either in the antecubital or uterine vein, was significantly higher in preeclampsia than in normal pregnancy (unpaired t-tests; both p < 0.001). There was no significant difference in the mean plasma concentration of PlGF between the uterine and the antecubital veins in both the preeclamptic (uterine vein, mean ± SD: 129 ± 106 pg/ml vs. antecubital vein, mean ± SD: 82 ± 43 pg/ml; paired t-tests, p = 0.2) and normal pregnancy groups (uterine vein, mean ± SD: 331 ± 254 pg/ml vs. antecubital vein, mean ± SD: 319 ± 259 pg/ml; paired t-tests, p = 0.4). The mean plasma concentration of PlGF, either in the uterine or antecubital vein, was lower in preeclampsia than in normal pregnancy (unpaired t-tests; p = 0.008 and 0.02 respectively). Conclusions. Plasma concentration of sVEGFR-1 was higher in the uterine vein than in the antecubital vein in women with preeclampsia. This provides evidence supporting the concept that the uterus is a potential source of the excess circulating sVEGFR-1 concentration in preeclamptic women.

The prevalence and clinical significance of amniotic fluid 'sludge' in patients with preterm labor and intact membranes

To determine the prevalence and clinical significance of amniotic fluid (AF) ‘sludge’ observed during transvaginal ultrasound examination of the cervix in patients with preterm labor and intact membranes, and in those with uncomplicated pregnancies.

Unexplained fetal death: Another anti-angiogenic state

Background. Pregnancy creates a unique situation in which both vasculogenesis and extensive angiogenesis are required for successful fetal and placental development. Recently, the soluble form of vascular endothelial growth factor (VEGF) receptor-1 (sVEGFR-1), an antagonist to VEGF and placental growth factor (PlGF) (two important angiogenic factors), has been implicated in the pathophysiology of preeclampsia and small for gestational age (SGA) without preeclampsia. There is, however, a paucity of information concerning plasma sVEGFR-1 concentrations in other obstetrical disorders. The purpose of this study was to determine plasma sVEGFR-1 concentrations in normal pregnancy, term gestation in labor, and in patients with pregnancy complications including spontaneous preterm labor, preterm premature rupture of the membranes (PROM), fetal death, and acute pyelonephritis. Methods. A cross-sectional study was conducted to determine the concentrations of sVEGFR-1 in plasma obtained from 499 women in the following groups: (1) non-pregnant women (n = 40); (2) pregnant women (n = 135); (3) normal pregnant women at term in labor (n = 60); (4) fetal death (n = 60); (5) spontaneous preterm labor with intact membranes (n = 102); (6) preterm PROM (n = 64); and (7) pregnancy with acute pyelonephritis (n = 38). Since plasma sVEGFR-1 concentration changes with gestational age, the difference between the actual and the expected plasma sVEGFR-1 concentration (derived from regression equation of normal pregnancy) for each patient (delta value) was calculated and used to examine the differences of plasma sVEGFR-1 concentrations among various groups. Plasma concentrations of sVEGFR-1 were determined by enzyme-linked immunoassay. Regression analysis and non-parametric statistics were used for analysis. Results. (1) Normal pregnant women before term had a median plasma sVEGFR-1 concentration significantly higher than non-pregnant women (p < 0.001); (2) plasma sVEGFR-1 concentration increased with advancing gestational age in normal pregnancy (r = 0.5; p < 0.001); (3) there was no significant difference in the median delta plasma concentration of sVEGFR-1 between normal pregnant women at term with and without labor (p = 0.09); (4) patients with fetal death had a median delta plasma concentration of sVEGFR-1 significantly higher than normal pregnant women (p = 0.001). Among patients with fetal death, those with unexplained causes (p = 0.04) and those with preeclampsia (p < 0.001) had a significantly higher delta plasma sVEGFR-1 concentration than normal pregnant women; and (5) there was no significant difference in the median delta plasma sVEGFR-1 concentration between normal pregnancy and preterm labor with intact membranes, preterm PROM (regardless of the presence or absence of microbial invasion of the amniotic cavity), or acute pyelonephritis (all p > 0.05). Conclusions. Plasma sVEGFR-1 concentration is increased in a subset of patients with fetal death, but does not change in term and preterm parturition, rupture of fetal membranes, or acute pyelonephritis.

Four-dimensional fetal echocardiography with spatiotemporal image correlation (STIC): A systematic study of standard cardiac views assessed by different observers

Objective. To test the agreement between observers and reproducibility of a technique to display standard cardiac views of the left and right ventricular outflow tracts from four-dimensional volume datasets acquired with Spatiotemporal Image Correlation (STIC). Methods. A technique was developed to obtain dynamic multiplanar images of the left ventricular outflow tract (LVOT) and right ventricular outflow tract (RVOT) from volume datasets acquired with STIC. Volume datasets were acquired from fetuses with normal cardiac anatomy. Twenty volume datasets of satisfactory quality were pre-selected by one investigator. The data was randomly assigned for a blinded review by two independent observers with previous experience in fetal echocardiography. Only one volume dataset was used for each fetus. After a training session, the observers obtained standardized cardiac views of the LVOT and RVOT, which were scored on a scale of 1 to 5, based on diagnostic value and image quality (1 = unacceptable, 2 = marginal, 3 = acceptable, 4 = good, and 5 = excellent). Median scores and interquartile range, as well as inter- and intraobserver agreement were calculated for each view. Results. The mean menstrual age at the time of volume acquisition was 25.5 ± 4.5 weeks. Median scores (interquartile range) for LVOT images, obtained by the first and second observers, were 3.5 (2.25–5.00) and 4 (3.00–5.00), respectively. The median scores (interquartile range) for RVOT images obtained by the first and second observers were 3 (3.00–5.00) and 3 (2.00–4.00), respectively. The interobserver intraclass correlation coefficient for the LVOT was 0.693 (95% CI 0.380–0.822), and 0.696 (95% CI 0.382–0.866) for the RVOT. For the intraobserver agreement analysis, observer 1 gave higher scores to the LVOT the second time the volumes were analyzed [LVOT: 3.50 (2.25–5.00) vs. 5.00 (4.00–5.00, p = 0.008)]. Conclusion. STIC can be reproducibly used to evaluate fetal cardiac outflow tracts by independent examiners. Slightly better image quality rating scores during the intraobserver variability trial suggests the presence of a learning curve for the manipulation and analysis of volume data obtained by STIC.

The Use of the Minimum Projection Mode in 4-Dimensional Examination of the Fetal Heart With Spatiotemporal Image Correlation

Objective. The minimum projection mode (MPM) is a rendering algorithm available in some 3‐ and 4‐dimensional ultrasonography systems that, in 1 image, allows the visualization of vessels and cystic anatomic structures located in different scanning planes. The objective of this study was to compare the information displayed in images obtained with the MPM with their corresponding 2‐dimensional ultrasonographic images from fetuses with and without structural heart defects. Methods. Thirty‐two volume data sets acquired with the spatiotemporal image correlation technique from fetuses with (n = 15) and without (n = 17) structural heart defects were analyzed. Rendered images of the upper abdomen, 4‐chamber view, and 3‐vessel view were compared with the corresponding 2‐dimensional images. Two independent observers with experience in fetal echocardiography reviewed these volume data sets using the MPM. The visualization rate of specific anatomic structures seen from a transverse sweep of the heart was recorded for each observer, and the interobserver agreement was assessed by statistical indices of agreement (κ statistic). Results. Images obtained by the MPM displayed more vascular structures than those of corresponding 2‐dimensional images at the level of the 3‐vessel view. For conotruncal anomalies, the minimum mode projected the aorta and pulmonary arteries in 1 single plane, facilitating the understanding of their spatial relationships. The interobserver agreement score was moderate to “almost perfect” for assessment of most anatomic structures in the upper abdomen, 4‐chamber view, and 3‐vessel view sections. However, interobserver agreement ranged from fair to poor for visualization of the left outflow tract, atrial septum, and flap of the foramen ovale. Conclusions. The MPM is an alternative rendering modality that facilitates visualization of normal and abnormal vascular connections to the fetal heart at the level of the 3‐vessel view. This technique may be useful in prenatal diagnosis of conotruncal anomalies and in assessment of the spatial relationships of abnormal vascular connections in the upper mediastinum.

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.

Imaging features of idiopathic intracranial hypertension, including a new finding: widening of the foramen ovale:

Background Idiopathic intracranial hypertension (IIH) is a clinical disorder of unknown etiology manifesting with increased intracranial pressure in the absence of hydrocephalus, an underlying mass lesion, and demonstrating normal cerebrospinal fluid composition. IIH may exhibit several non-specific imaging findings including: an empty sella, posterior globe flattening, tortuosity of the optic nerve, and optic nerve sheath distention. Purpose To introduce widening of the foramen ovale as a new imaging marker for IIH. Material and Methods IIH is a syndrome which may exhibit several previously described non-specific imaging findings including: an empty sella, posterior globe flattening, tortuosity of the optic nerve, and optic nerve sheath distention. We hypothesize that chronically elevated cerebrospinal fluid pressure can lead to osseous erosions and we propose widening of the foramen ovale as a new imaging marker for IIH. Results Average foramen ovale sizes were increased in patients with IIH compared to controls (30.03 ± 7.00 mm2 vs. 24.21 ± 5.97 mm2, P < 0.001). For a cut-off value of 30 mm2, the sensitivity of FO area to detect IIH was 50%, with 81% specificity. Classic findings were significantly more common in patients with IIH compared to controls including: empty sella (65.9% vs. 0%), posterior globe flattening (65.9% vs. 4.5%), vertical tortuosity of the optic nerve (54.5% vs. 9.1%), and optic nerve sheath distention (52.3% vs. 11.4%, all P values < 0.001). Conclusion Our study confirms the association of several classic imaging findings with IIH and supports widening of the foramen ovale as an additional imaging marker which may be incorporated into the evaluation of patients suspected to have this condition.