Systematic design and evaluation of aptamers for VEGF and PlGF biomarkers of Preeclampsia.

Preeclampsia is a potentially life-threatening condition for both mother and baby, characterized by hypertension and potential organ damage. Early diagnosis is crucial to mitigate its adverse health effects. Traditional diagnostic methods, which focus on late-manifesting symptoms like hypertension and proteinuria, underscore the need for molecular diagnostic approaches for timely detection. This study successfully designs and evaluates novel aptamers with high specificity and affinity for Vascular Endothelial Growth Factor (VEGF) and Placental Growth Factor (PlGF), biomarkers closely associated with preeclampsia. Using molecular docking, molecular dynamics simulations, and BioLayer Interferometry (BLI), we identified aptamers that demonstrated strong binding affinities, comparable or superior to traditional antibodies. Our findings suggest that these aptamers have the potential to be integrated into cost-effective, point-of-care diagnostic tools, significantly improving early detection and intervention strategies for preeclampsia. The robust performance of these aptamers marks a pivotal step toward the development of more reliable and accessible diagnostic solutions, with implications for better maternal and fetal health outcomes.

Vascular endothelial growth factors and risk of cardio-renal events: Results from the CREDENCE trial.

BACKGROUND: Circulating concentrations of vascular endothelial growth factor (VEGF) family members may be abnormally elevated in type 2 diabetes (T2D). The roles of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFLT-1), and VEGF-A in cardio-renal complications of T2D are not established. METHOD: The 2602 individuals with diabetic kidney disease (DKD) from the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation trial were randomized to receive canagliflozin or placebo and followed for incident cardio-renal outcomes. PlGF, sFLT-1, and VEGF-A were measured at baseline, year 1, and year 3. Primary outcome was a composite of end-stage kidney disease, doubling of the serum creatinine, or renal/cardiovascular death. Cox proportional hazard regression was used to investigate the association between biomarkers with adverse clinical events. RESULTS: At baseline, individuals with higher PlGF levels had more prevalent cardiovascular disease compared to those with lower values. Treatment with canagliflozin did not meaningfully change PlGF, sFLT-1, and VEGF-A concentrations at years 1 and 3. In a multivariable model, 1 unit increases in baseline log PlGF (hazard ratio [HR]: 1.76, 95% confidence interval [CI]: 1.23, 2.54, P-value = .002), sFLT-1 (HR: 3.34, [95% CI: 1.71, 6.52], P-value < .001), and PlGF/sFLT-1 ratio (HR: 4.83, [95% CI: 0.86, 27.01], P-value = .07) were associated with primary composite outcome, while 1 unit increase in log VEGF-A did not increase the risk of primary outcome (HR: 0.96 [95% CI: 0.81, 1.07]). Change by 1 year of each biomarker was also assessed: HR (95% CI) of primary composite outcome was 2.45 (1.70, 3.54) for 1 unit increase in 1-year concentration of log PlGF, 4.19 (2.18, 8.03) for 1 unit increase in 1-year concentration of log sFLT-1, and 21.08 (3.79, 117.4) for 1 unit increase in 1-year concentration of log PlGF/sFLT-1. Increase in 1-year concentrations of log VEGF-A was not associated with primary composite outcome (HR: 1.08, [95% CI: 0.93, 1.24], P-value = .30). CONCLUSIONS: People with T2D and DKD with elevated levels of PlGF, sFLT-1, and PlGF/sFLT-1 ratio were at a higher risk for cardiorenal events. Canagliflozin did not meaningfully decrease concentrations of PlGF, sFLT-1, and VEGF-A. CLINICAL TRIAL: CREDENCE, https://clinicaltrials.gov/ct2/show/NCT02065791.

Discussion on the evaluation of the therapeutic efficacy of uterine artery blood flow parameters and serum PLGF and sFlt-1 in patients with recurrent spontaneous abortion.

OBJECTIVE: To investigate the effects of different drug treatments on uterine artery blood flow parameters, serum placental growth factor (PLGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and sFlt-1/PLGF in patients with recurrent spontaneous abortion and to explore the predictive value of uterine artery blood flow parameters, serum PLGF, sFlt-1, and sFlt-1/PLGF for pregnancy outcomes. METHODS: This retrospective cohort study included 173 patients who experienced recurrent spontaneous abortion and 100 control patients. Patients with recurrent spontaneous abortion were divided into an aspirin group (75 patients), aspirin combined with low molecular weight heparin (LMWH) group (68 patients), and non-drug group (30 patients) based on different drug treatments. Uterine artery blood flow parameters at gestational weeks 30-31+6 were monitored for the four groups, and serum samples were collected at gestational weeks 30-31+6 to measure the levels of serum PLGF and sFlt-1 and calculate the sFlt-1/PLGF ratio. RESULTS: 1. Uterine artery blood flow parameters at gestational weeks 30-31+6 were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 2. Serum PLGF levels and the sFlt-1/PLGF ratio at gestational weeks 30-31+6 were significantly lower in the non-drug group than in the aspirin group, combined drug group, and control group, while serum sFlt-1 levels were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 3. Serum PLGF, sFlt-1, and sFlt-1/PLGF had lower diagnostic efficiency for predicting hypertensive disorders during pregnancy than the combined diagnostic efficiency of serum PLGF, sFlt-1, and sFlt-1/PLGF with uterine artery blood flow parameters at gestational weeks 30-31+6. CONCLUSION: Aspirin and aspirin combined with LMWH can upregulate serum PLGF and decrease serum sFlt-1 levels in patients with recurrent spontaneous abortion, reduce the miscarriage rate, and significantly improve pregnancy outcomes. The combination of serum PLGF, sFlt-1, sFlt-1/PLGF, and uterine artery blood flow parameters can effectively predict hypertensive disorders during pregnancy.

First trimester risk of preeclampsia and rate of spontaneous birth in patients without preeclampsia.

BACKGROUND: First-trimester screening for preeclampsia using a combination of maternal risk factors and mean arterial pressure, uterine artery pulsatility index, and placental growth factor, as proposed by the Fetal Medicine Foundation, provides effective prediction of preterm preeclampsia. Placental dysfunction is a potential precursor of spontaneous birth. OBJECTIVE: The objective of this study was to examine if the estimated risk of preeclampsia is associated with the gestational age at onset of spontaneous delivery in the absence of preeclampsia. STUDY DESIGN: This was a secondary analysis of the data from the Screening programme for pre-eclampsia trial in which there was a comparison of the performance of first-trimester screening for preterm preeclampsia using the Fetal Medicine Foundation model vs a traditional history-based risk scoring system. A subgroup of women from the trial with spontaneous onset of delivery (labor with intact membranes or preterm prelabor rupture of membranes) was included in this study and was arbitrarily divided into 3 groups according to the risk for preterm preeclampsia as determined by the Fetal Medicine Foundation model at 11 to 13 weeks' gestation as follows: group 1 low risk (˂1/100); group 2 intermediate risk (1/50 to 1/100); and group 3 high risk (˃1/50). A survival analysis was carried out using a Kaplan-Meier estimator and a Cox regression analysis with stratification by the 3 preeclampsia risk groups. Occurrence of spontaneous birth in the study groups was compared using log-rank tests and hazard ratios. RESULTS: The study population comprised 10,820 cases with delivery after spontaneous onset of labor among the 16,451 cases who participated in the Screening programme for pre-eclampsia trial. There were 9795 cases in group 1, 583 in group 2, and 442 in group 3. The gestational age at delivery was <28, <32, <35, <37, and <40 weeks in 0.29%, 0.64%, 1.68%, 4.52%, and 44.97% of cases, respectively, in group 1; 0.69%, 1.71%, 3.26%, 7.72%, and 55.23% of cases, respectively, in group 2; and 0.45%, 1.81%, 5.66%, 13.80%, and 63.12% of cases, respectively, in group 3. The curve profile of gestational age at spontaneous birth in the 3 study groups was significantly different overall and in pairwise comparisons (P values <.001). The Cox regression analysis showed that risks increased for spontaneous birth by 18% when the intermediate-risk group was compared with the low-risk group (P˂.001) and by 41% when the high-risk group was compared with the low-risk group (P˂.001). CONCLUSION: In this study that investigated birth after spontaneous onset of labor in women without preeclampsia, there were 2 major findings. First, the duration of pregnancy decreased with increasing first-trimester risk for preeclampsia. Second, in the high-risk group, when compared with the low-risk group, the risk for spontaneous birth was 4 times higher at a gestational age of 24 to 26 weeks, 3 times higher at 28 to 32 weeks, and 2 times higher at 34 to 39 weeks. These differences present major clinical implications for antepartum counselling, monitoring, and interventions in these pregnancies.

Aspirin for evidence-based preeclampsia prevention trial: effects of aspirin on maternal serum pregnancy-associated plasma protein A and placental growth factor trajectories in pregnancy.

BACKGROUND: The exact mechanism by which aspirin prevents preeclampsia remains unclear. Its effects on serum placental biomarkers throughout pregnancy are also unknown. OBJECTIVE: To investigate the effects of aspirin on serum pregnancy-associated plasma protein A and placental growth factor trajectories using repeated measures from women at increased risk of preterm preeclampsia. STUDY DESIGN: This was a longitudinal secondary analysis of the Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-based Preeclampsia Prevention trial using repeated measures of pregnancy-associated plasma protein A and placental growth factor. In the trial, 1620 women at increased risk of preterm preeclampsia were identified using the Fetal Medicine Foundation algorithm at 11 to 13+6 weeks of gestation, of whom 798 were randomly assigned to receive aspirin 150 mg and 822 to receive placebo daily from before 14 weeks to 36 weeks of gestation. Serum biomarkers were measured at baseline and follow-up visits at 19 to 24, 32 to 34, and 36 weeks of gestation. Generalized additive mixed models with treatment by gestational age interaction terms were used to investigate the effect of aspirin on biomarker trajectories over time. RESULTS: Overall, there were 5507 pregnancy-associated plasma protein A and 5523 placental growth factor measurements. Raw pregnancy-associated plasma protein A values increased over time, and raw placental growth factor increased until 32 weeks of gestation followed by a decline. The multiple of the median mean values of the same biomarkers were consistently below 1.0 multiple of the median, reflecting the high-risk profile of the study population. Trajectories of mean pregnancy-associated plasma protein A and placental growth factor multiple of the median values did not differ significantly between the aspirin and placebo groups (aspirin treatment by gestational age interaction P values: .259 and .335, respectively). CONCLUSION: In women at increased risk of preterm preeclampsia, aspirin 150 mg daily had no significant effects on pregnancy-associated plasma protein A or placental growth factor trajectories when compared to placebo.

Plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio of 11.5 multiples of median predicts preeclampsia with severe features within 2 weeks of testing.

BACKGROUND: Angiogenic imbalances, characterized by an excess of antiangiogenic factors (soluble fms-like tyrosine kinase 1) and reduced angiogenic factors (vascular endothelial growth factor and placental growth factor), contribute to the mechanisms of disease in preeclampsia. The ratio of soluble fms-like tyrosine kinase 1 to placental growth factor has been used as a biomarker for preeclampsia, but the cutoff values may vary with gestational age and assay platform. OBJECTIVE: This study aimed to compare multiples of the median of the maternal plasma soluble fms-like tyrosine kinase 1 to placental growth factor ratio, soluble fms-like tyrosine kinase 1, placental growth factor, and conventional clinical and laboratory values in their ability to predict preeclampsia with severe features. STUDY DESIGN: We conducted a cohort study across 18 United States centers involving hospitalized individuals with hypertension between 23 and 35 weeks' gestation. Receiver operating characteristic curve analyses of maternal plasma biomarkers, highest systolic or diastolic blood pressures, and laboratory values at enrollment were performed for the prediction of preeclampsia with severe features. The areas under the curve were compared, and quasi-Poisson regression models were fitted to estimate relative risks. The primary outcome was preeclampsia with severe features within 2 weeks of enrollment. Secondary outcomes were a composite of severe adverse maternal outcomes (elevated liver enzymes, low platelets count, placental abruption, eclampsia, disseminated intravascular coagulation, and pulmonary edema) and a composite of severe adverse perinatal outcomes (birth weight below the third percentile, very preterm birth [<32 weeks' gestation], and fetal or neonatal death). RESULTS: Of the 543 individuals included in the study, preeclampsia with severe features within 2 weeks was observed in 33.1% (n=180) of them. A receiver operating characteristic curve-derived cutoff of 11.5 multiples of the median for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio provided good sensitivity (90.6%), specificity (76.9%), positive predictive value (66.0%), negative predictive value (94.3%), positive likelihood ratio (3.91), negative likelihood ratio (0.12), and accuracy (81.4%) for preeclampsia with severe features within 2 weeks. This cutoff was used to compare test positive cases (≥ cutoff) and test negative cases (< cutoff). Preeclampsia with severe features (66.0% vs 5.7%; P<.001) and composites of severe adverse maternal (8.11% vs 2.7%; P=.006) or perinatal (41.3% vs 10.14%; P=.001) outcomes within 2 weeks were more frequent in test positive cases than in test negative cases. A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the median was independently associated with preeclampsia with severe features (adjusted incidence rate ratio, 9.08; 95% confidence interval, 6.11-14.06; P<.001) and a composite of severe adverse perinatal outcomes (adjusted incidence rate ratio, 9.42; 95% confidence interval, 6.36-14.53; P<.001) but not with a composite of severe adverse maternal outcomes (adjusted incidence rate ratio, 2.20; 95% confidence interval, 0.95-5.54; P=.08). The area under the curve for the soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio in multiples of the median (0.91; 95% confidence interval, 0.89-0.94) for preeclampsia with severe features within 2 weeks was significantly higher (P<.001 for all comparisons) than either plasma biomarker alone or any other parameter with the exception of absolute soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio values. CONCLUSION: A soluble fms-like tyrosine kinase 1 to placental growth factor plasma ratio ≥11.5 multiples of the mean among hospitalized patients with hypertension between 23 and 35 week's gestation predicts progression to preeclampsia with severe features and severe adverse perinatal outcomes within 2 weeks.

Prediction of preterm birth in growth-restricted and appropriate-for-gestational-age infants using maternal PlGF and the sFlt-1/PlGF ratio-A prospective study.

OBJECTIVE: To assess the utility of placental growth factor (PlGF) levels and the soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict preterm birth (PTB) for infants with fetal growth restriction (FGR) and those appropriate for gestational age (AGA). DESIGN: Prospective, observational cohort study. SETTING: Tertiary maternity hospital in Australia. POPULATION: There were 320 singleton pregnancies: 141 (44.1%) AGA, 83 (25.9%) early FGR (<32+0 weeks) and 109 (30.0%) late FGR (≥32+0 weeks). METHODS: Maternal serum PlGF and sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. Low maternal PlGF levels and elevated sFlt-1/PlGF ratio were defined as <100 ng/L and >5.78 if <28 weeks and >38 if ≥28 weeks respectively. Cox proportional hazards models were used. The analysis period was defined as the time from the first measurement of PlGF and sFlt-1/PlGF ratio to the time of birth or censoring. MAIN OUTCOME MEASURES: The primary study outcome was overall PTB. The relative risks (RR) of birth within 1, 2 and 3 weeks and for medically indicated and spontaneous PTB were also ascertained. RESULTS: The early FGR cohort had lower median PlGF levels (54 versus 229 ng/L, p < 0.001) and higher median sFlt-1 levels (2774 ng/L versus 2096 ng/L, p < 0.001) and sFlt-1/PlGF ratio higher (35 versus 10, p < 0.001). Both PlGF <100 ng/L and elevated sFlt-1/PlGF ratio were strongly predictive for PTB as well as PTB within 1, 2 and 3 weeks of diagnosis. For both FGR and AGA groups, PlGF <100 ng/L or raised sFlt-1/PlGF ratio were strongly associated with increased risk for medically indicated PTB. The highest RR was seen in the FGR cohort when PlGF was <100 ng/L (RR 35.20, 95% CI 11.48-175.46). CONCLUSIONS: Low maternal PlGF levels and elevated sFlt-1/PlGF ratio are potentially useful to predict PTB in both FGR and AGA pregnancies.

B-flow/spatiotemporal image correlation M-mode ultrasound provides novel method to quantify spiral artery remodeling during normal human pregnancy.

OBJECTIVES: During human pregnancy, placental extravillous trophoblasts replace vascular smooth muscle and elastic tissue within the walls of the uterine spiral arteries, thereby remodeling them into distensible low-resistance vessels to promote placental perfusion. The present study determined whether B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography provides an in-vivo imaging method able to digitally quantify spiral artery luminal distensibility as a physiological index of spiral artery remodeling during the advancing stages of normal human pregnancy. METHODS: A prospective, longitudinal, observational study was conducted to quantify spiral artery distensibility (i.e. vessel luminal diameter at systole minus diameter at diastole) by B-flow/STIC M-mode ultrasonography during the first, second and third trimesters in 290 women exhibiting a normal pregnancy. Maternal serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), growth factors that modulate important events in spiral artery remodeling, were quantified in a subset of the women in the first, second and third trimesters of pregnancy. RESULTS: Median (interquartile range (IQR)) spiral artery distensibility increased progressively between the first (0.17 (0.14-0.21) cm), second (0.23 (0.18-0.28) cm) and third (0.26 (0.21-0.35) cm) trimesters of pregnancy (P < 0.0001 for all). Median (IQR) spiral artery volume flow increased progressively between the first (2.49 (1.38-4.99) mL/cardiac cycle), second (3.86 (2.06-6.91) mL/cardiac cycle) and third (7.79 (3.83-14.98) mL/cardiac cycle) trimesters (P < 0.001 for all). In accordance with the elevation in spiral artery distensibility, the median (IQR) ratio of serum PlGF/sFlt-1 × 103 levels increased between the first (7.2 (4.5-10.0)), second (22.7 (18.6-42.2)) and third (56.2 (41.9-92.5)) trimesters (P < 0.001 for all). CONCLUSIONS: The present study shows that B-flow/STIC M-mode ultrasonography provides an in-vivo imaging technology to quantify digitally the structural and physiological expansion of the walls of the spiral arteries during the cardiac cycle as a consequence of their transformation into compliant vessels during advancing stages of normal human pregnancy. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Maternal cardiovascular function in midgestation is related to placental angiogenesis.

OBJECTIVE: To investigate whether angiogenic markers of placental function are associated with maternal cardiac function and hemodynamic responses at 19-23 weeks' gestation, controlling for maternal risk factors and pregnancy complications. METHODS: This was a prospective study of women with singleton pregnancy attending King's College Hospital, London, UK, for a routine hospital visit at 19-23 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure (MAP), maternal heart rate, serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). We also performed maternal echocardiography to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function. RESULTS: Our cohort included 4006 women. Lower PlGF values were significantly associated with higher MAP (P < 0.0001), lower maternal heart rate (P < 0.0001), lower mitral valve s' mean velocity (P = 0.027) and higher left atrial area (P = 0.022) after adjustment for maternal characteristics and pregnancy complications. sFlt-1 was associated positively with relative wall thickness (P = 0.012), whereas sFlt-1/PlGF ratio was associated negatively with mitral valve A (P = 0.006) and positively with left atrial area (P = 0.015) and MAP (P = 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors based on their obstetric and medical history. CONCLUSIONS: A continuous association of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present in midgestation, independently of pre-existing maternal risk factors and pregnancy complications. Impaired placental function appears to be related to mild systolic and diastolic dysfunction and cardiac remodeling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Comparison of different methods of first-trimester screening for preterm pre-eclampsia: cohort study.

OBJECTIVE: To compare the predictive performance of three different mathematical models for first-trimester screening of pre-eclampsia (PE), which combine maternal risk factors with mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF), and two risk-scoring systems. METHODS: This was a prospective cohort study performed in eight fetal medicine units in five different regions of Spain between September 2017 and December 2019. All pregnant women with singleton pregnancy and a non-malformed live fetus attending their routine ultrasound examination at 11 + 0 to 13 + 6 weeks' gestation were invited to participate in the study. Maternal characteristics and medical history were recorded and measurements of MAP, UtA-PI, serum PlGF and pregnancy-associated plasma protein-A (PAPP-A) were converted into multiples of the median (MoM). Risks for term PE, preterm PE (< 37 weeks' gestation) and early PE (< 34 weeks' gestation) were calculated according to the FMF competing-risks model, the Crovetto et al. logistic regression model and the Serra et al. Gaussian model. PE classification was also performed based on the recommendations of the National Institute for Health and Care Excellence (NICE) and the American College of Obstetricians and Gynecologists (ACOG). We estimated detection rates (DR) with their 95% CIs at a fixed 10% screen-positive rate (SPR), as well as the area under the receiver-operating-characteristics curve (AUC) for preterm PE, early PE and all PE for the three mathematical models. For the scoring systems, we calculated DR and SPR. Risk calibration was also assessed. RESULTS: The study population comprised 10 110 singleton pregnancies, including 32 (0.3%) that developed early PE, 72 (0.7%) that developed preterm PE and 230 (2.3%) with any PE. At a fixed 10% SPR, the FMF, Crovetto et al. and Serra et al. models detected 82.7% (95% CI, 69.6-95.8%), 73.8% (95% CI, 58.7-88.9%) and 79.8% (95% CI, 66.1-93.5%) of early PE; 72.7% (95% CI, 62.9-82.6%), 69.2% (95% CI, 58.8-79.6%) and 74.1% (95% CI, 64.2-83.9%) of preterm PE; and 55.1% (95% CI, 48.8-61.4%), 47.1% (95% CI, 40.6-53.5%) and 53.9% (95% CI, 47.4-60.4%) of all PE, respectively. The best correlation between predicted and observed cases was achieved by the FMF model, with an AUC of 0.911 (95% CI, 0.879-0.943), a slope of 0.983 (95% CI, 0.846-1.120) and an intercept of 0.154 (95% CI, -0.091 to 0.397). The NICE criteria identified 46.7% (95% CI, 35.3-58.0%) of preterm PE at 11% SPR and ACOG criteria identified 65.9% (95% CI, 55.4-76.4%) of preterm PE at 33.8% SPR. CONCLUSIONS: The best performance of screening for preterm PE is achieved by mathematical models that combine maternal factors with MAP, UtA-PI and PlGF, as compared to risk-scoring systems such as those of NICE and ACOG. While all three algorithms show similar results in terms of overall prediction, the FMF model showed the best performance at an individual level. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Predictive value of maternal serum placental growth factor levels for discordant fetal growth in twins: a retrospective cohort study.

BACKGROUND: Accurate prenatal recognition of discordant fetal growth in twins is critical for deciding suitable management strategies. We explored the predictive value of the level of maternal second-trimester placental growth factor (PLGF) as a novel indicator of discordant fetal growth. METHODS: A total of 860 women pregnant with twins were enrolled, including 168 women with monochorionic twins (31 cases of discordant fetal growth and 137 without) and 692 with dichorionic twins (79 cases of discordant fetal growth and 613 without). Maternal second-trimester PLGF concentrations were measured via immunofluorescence. RESULTS: Maternal second-trimester PLGF levels were significantly lower in women pregnant with twins who subsequently developed discordant fetal growth than in those who did not (monochorionic twin pregnancy: P < 0.001; dichorionic twin pregnancy: P < 0.001). A 3-4 fold difference in median PLGF concentrations was detected between the two groups with both monochorionic and dichorionic twin pregnancies. Maternal second-trimester PLGF levels were significantly correlated with birth weight differences (monochorionic twin pregnancy: r = - 0.331, P < 0.001; dichorionic twin pregnancy: r = - 0.234, P < 0.001). A receiver operating characteristic curve was used to evaluate the predictive efficiency. In monochorionic twin pregnancies, the area under the curve (AUC) was 0.751 (95% confidence interval [CI]: 0.649-0.852), and the cutoff value was 187.5 pg/mL with a sensitivity of 77.4% and specificity of 71.0%. In dichorionic twin pregnancies, the AUC was 0.716 (95% CI; 0.655-0.777), and the cutoff value was 252.5 pg/mL with a sensitivity of 65.1% and specificity of 69.6%. Based on the above cutoff values, univariate and multivariate logistic regression analyses were performed to calculate the odds ratios (OR) for the PLGF levels. After adjustment for potential confounding factors, low PLGF concentrations still significantly increased the risk of discordant fetal growth (monochorionic twin pregnancy: adjusted OR: 7.039, 95% CI: 2.798-17.710, P < 0.001; dichorionic twin pregnancy: adjusted OR: 4.279, 95% CI: 2.572-7.120, P < 0.001). CONCLUSIONS: A low maternal second-trimester PLGF level is considered a remarkable risk factor and potential predictor of discordant fetal growth. This finding provides a complementary screening strategy for the prediction of discordant fetal growth and offers a unique perspective for the subsequent research in this field.

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation.

INTRODUCTION: This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations. MATERIAL AND METHODS: This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians. RESULTS: Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, vs negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion. CONCLUSIONS: Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

A dynamic prediction model for preeclampsia using the sFlt-1/PLGF ratio combined with multiple factors.

OBJECTIVE: Preeclampsia (PE) is a pregnancy-related multi-organ disease and a significant cause of incidence rate and mortality of pregnant women and newborns worldwide. Delivery remains the only available treatment for PE. This study aims to establish a dynamic prediction model for PE. METHODS: A total of 737 patients who visited our hospital from January 2021 to June 2022 were identified according to the inclusion and exclusion criteria, forming the primary dataset. Additionally, 176 singleton pregnant women who visited our hospital from July 2022 to November 2022 comprised the verification set. We investigated different gestational weeks of sFlt-1/PLGF (soluble FMS-like tyrosine kinase-1, placental growth factor) ratio combined with maternal characteristics and routine prenatal laboratory results in order to predict PE in each trimester. Multivariate logistic regression was used to establish the prediction model for PE at different gestational weeks. The discrimination, calibration, and clinical validity were utilized to evaluate predictive models as well as models in external validation queues. RESULTS: At 20-24 weeks, the obtained prediction model for PE yielded an area under the curve of 0.568 (95% confidence interval, 0.479-0.657). At 25-29 weeks, the obtained prediction model for PE yielded an area under the curve of 0.773 (95% confidence interval, 0.703-0.842)and 0.731 (95% confidence interval, 0.653-0.809) at 30-34 weeks. After adding maternal factors, uterine artery pulsation index(Ut-IP), and other laboratory indicators to the sFlt-1/PLGF ratio, the predicted performance of PE improved. It found that the AUC improved to 0.826(95% confidence interval, 0.748 ∼ 0.904) at 20-24 weeks, 0.879 (95% confidence interval, 0.823 ∼ 0.935) at 25-29 weeks, and 0.862(95% confidence interval, 0.799 ∼ 0.925) at 30-34 weeks.The calibration plot of the prediction model indicates good predictive accuracy between the predicted probability of PE and the observed probability. Furthermore, decision-curve analysis showed an excellent clinical application value of the models. CONCLUSION: Using the sFlt-1/PLGF ratio combined with multiple factors at 25-29 weeks can effectively predict PE, but the significance of re-examination in late pregnancy is not significant.

Prediction of preterm birth in women with fetal growth restriction - Is the weekly change in sFlt-1/PlGF ratio or PlGF levels useful?

INTRODUCTION: To assess the rate of change in soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio and PlGF levels per week compared to a single sFlt-1/PlGF ratio or PlGF level to predict preterm birth for pregnancies complicated by fetal growth restriction. MATERIAL AND METHODS: A prospective cohort study of pregnancies complicated by isolated fetal growth restriction. Maternal serum PlGF levels and the sFlt-1/PlGF ratio were measured at 4-weekly intervals from recruitment to delivery. We investigated the utility of PlGF levels, sFlt-1/PlGF ratio, change in PlGF levels per week or sFlt-1/PlGF ratio per week. Cox-proportional hazard models and Harrell's C concordance statistic were used to evaluate the effect of biomarkers on time to preterm birth. RESULTS: The total study cohort was 158 pregnancies comprising 91 (57.6%) with fetal growth restriction and 67 (42.4%) with appropriate for gestational age controls. In the fetal growth restriction cohort, sFlt-1/PlGF ratio and PlGF levels significantly affected time to preterm birth (Harrell's C: 0.85-0.76). The rate of increase per week of the sFlt-1/PlGF ratio (hazard ratio [HR] 3.91, 95% confidence interval [CI]: 1.39-10.99, p = 0.01, Harrell's C: 0.74) was positively associated with preterm birth but change in PlGF levels per week was not (HR 0.65, 95% CI: 0.25-1.67, p = 0.37, Harrell's C: 0.68). CONCLUSIONS: Both a high sFlt-1/PlGF ratio and low PlGF levels are predictive of preterm birth in women with fetal growth restriction. Although the rate of increase of the sFlt-1/PlGF ratio predicts preterm birth, it is not superior to either a single elevated sFlt-1/PlGF ratio or low PlGF level.

Maternal serum biomarkers of placental insufficiency at 24-28 weeks of pregnancy in relation to the risk of delivering small-for-gestational-age infant in Sylhet, Bangladesh: a prospective cohort study.

BACKGROUND: Small-for-gestational-age (SGA), commonly caused by poor placentation, is a major contributor to global perinatal mortality and morbidity. Maternal serum levels of placental protein and angiogenic factors are changed in SGA. Using data from a population-based pregnancy cohort, we estimated the relationships between levels of second-trimester pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF), and serum soluble fms-like tyrosine kinase-1 (sFlt-1) with SGA. METHODS: Three thousand pregnant women were enrolled. Trained health workers prospectively collected data at home visits. Maternal blood samples were collected, serum aliquots were prepared and stored at -80℃. Included in the analysis were 1,718 women who delivered a singleton live birth baby and provided a blood sample at 24-28 weeks of gestation. We used Mann-Whitney U test to examine differences of the median biomarker concentrations between SGA (< 10th centile birthweight for gestational age) and appropriate-for-gestational-age (AGA). We created biomarker concentration quartiles and estimated the risk ratios (RRs) and 95% confidence intervals (CIs) for SGA by quartiles separately for each biomarker. A modified Poisson regression was used to determine the association of the placental biomarkers with SGA, adjusting for potential confounders. RESULTS: The median PlGF level was lower in SGA pregnancies (934 pg/mL, IQR 613-1411 pg/mL) than in the AGA (1050 pg/mL, IQR 679-1642 pg/mL; p < 0.001). The median sFlt-1/PlGF ratio was higher in SGA pregnancies (2.00, IQR 1.18-3.24) compared to AGA pregnancies (1.77, IQR 1.06-2.90; p = 0.006). In multivariate regression analysis, women in the lowest quartile of PAPP-A showed 25% higher risk of SGA (95% CI 1.09-1.44; p = 0.002). For PlGF, SGA risk was higher in women in the lowest (aRR 1.40, 95% CI 1.21-1.62; p < 0.001) and 2nd quartiles (aRR 1.30, 95% CI 1.12-1.51; p = 0.001). Women in the highest and 3rd quartiles of sFlt-1 were at reduced risk of SGA delivery (aRR 0.80, 95% CI 0.70-0.92; p = 0.002, and aRR 0.86, 95% CI 0.75-0.98; p = 0.028, respectively). Women in the highest quartile of sFlt-1/PlGF ratio showed 18% higher risk of SGA delivery (95% CI 1.02-1.36; p = 0.025). CONCLUSIONS: This study provides evidence that PAPP-A, PlGF, and sFlt-1/PlGF ratio measurements may be useful second-trimester biomarkers for SGA.

Biomarkers for Early Prediction and Management of Preeclampsia: A Comprehensive Review.

Preeclampsia is a common complication of pregnancy. It is a multi-organ disorder that remains one of the main causes of maternal morbidity and mortality. Additionally, preeclampsia leads to many complications that can occur in the fetus or newborn. Preeclampsia occurs in about 1 in 20 pregnant women. This review focuses on the prediction of preeclampsia in women, using various biomarkers, in particular, a factor combining the use of soluble FMS-like tyrosinokinase-1 (sFlt-1) and placental growth factor (PlGF). A low value of the sFlt-1/PlGF ratio rules out the occurrence of preeclampsia within 4 weeks of the test result, and its high value predicts the occurrence of preeclampsia within even 1 week. The review also highlights other factors, such as pregnancy-associated plasma protein A, placental protein 13, disintegrin and metalloprotease 12, ß-human chorionic gonadotropin, inhibin-A, soluble endoglin, nitric oxide, and growth differentiation factor 15. Biomarker testing offers reliable and cost-effective screening methods for early detection, prognosis, and monitoring of preeclampsia. Early diagnosis in groups of women at high risk for preeclampsia allows for quick intervention, preventing the undesirable effects of preeclampsia. However, further research is needed to validate and optimize the use of biomarkers for more accurate prediction and diagnosis. This article aims to review the role of biomarkers, including the sFlt1/PlGF ratio, in the prognosis and management of preeclampsia.

Stability of serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1).

Placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) are biomarkers used for diagnosis and risk estimation of preeclampsia. Stability in room temperature (RT) may affect the usefulness of these analyses, as shipping at ambient temperature is the most practical and suitable way to ship samples. To date, scientific studies of such stability are lacking. We aimed to assess the stability of PlGF and sFlt-1 at RT in serum from pregnant women. In addition, a smaller study of stability at 4 °C was performed. Serum was collected from 69 pregnant women and stored at RT or at 4 °C for up to 192 h. Analytes were considered stable if the mean percent change ± 90 confidence interval of the mean was within the baseline concentration ± allowable bias. Allowable bias was calculated from data on biological variation. In addition, an instability equation was calculated to assess loss of stability, in line with recent European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recommendations. The mean percent change was <3.5% for PlGF, <1% for sFlt-1 and <4.5% for sFlt-1/PlGF ratio up to 192 h. PlGF was considered stable for 168 h, and sFlt-1 and sFlt-1/PlGF ratios were considered stable for 192 h at RT. At 4 °C, PlGF was considered stable for 120 h, sFlt-1 for 168 h and sFlt-1/PlGF ratio for 120 h. Both PlGF and sFlt-1 as well as sFlt-1/PlGF ratio show sufficient stability (minimum 168 h) for samples to be shipped at RT.

B7-1 and PlGF-1 are two possible new biomarkers to identify fracture-associated trauma patients at higher risk of developing complications: a cohort study.

BACKGROUND: Around 10% of fractures lead to complications. With increasing fracture incidences in recent years, this poses a serious burden on the healthcare system, with increasing costs for treatment. In the present study, we aimed to identify potential 'new' blood markers to predict the development of post-surgical complications in trauma patients following a fracture. METHODS: A total of 292 trauma patients with a complete three-month follow-up were included in this cohort study. Blood samples were obtained from 244 of these patients. Two complication groups were distinguished based on the Clavien-Dindo (CD) classification: CD grade I and CD grade III groups were compared to the controls (CD 0). The Mann-Whitney U test was used to compare the complication groups to the control group. RESULTS: Analysis of the patients' data revealed that risk factors are dependent on sex. Both, males and females who developed a CD III complication showed elevated blood levels of B7-1 (p = 0.015 and p = 0.018, respectively) and PlGF-1 (p = 0.009 and p = 0.031, respectively), with B7-1 demonstrating greater sensitivity (B7-1: 0.706 (male) and 0.692 (female), PlGF-1: 0.647 (male) and 0.615 (female)). Further analysis of the questionnaires and medical data revealed the importance of additional risk factors. For males (CD 0: 133; CD I: 12; CD III: 18 patients) alcohol consumption was significantly increased for CD I and CD III compared to control with p = 0.009 and p = 0.007, respectively. For females (CD 0: 107; CD I: 10; CD III: 12 patients) a significantly increased average BMI [kg/m2] from 25.5 to 29.7 with CD III was observed, as well as an elevation from one to three comorbidities (p = 0.003). CONCLUSIONS: These two potential new blood markers hold promise for predicting complication development in trauma patients. Nevertheless, further studies are necessary to evaluate the diagnostic utility of B7-1 and PlGF-1 in predicting complications in trauma patients and consider sex differences before their possible use as routine clinical screening tools.

Prediction of preeclampsia using maternal circulating mRNAs in early pregnancy.

PURPOSE: Preeclampsia (PE) is one of the most common and serious complications of pregnancy, and novel methods for the early prediction of PE are needed for clinical application. METHODS: In this study, a circulating cell-free RNA (cfRNA) panel of target genes for PE prediction was designed and validated in a case-control cohort and a nested case-control cohort. The QPCR was applied to quantify the copy number of cfRNA, and the data were normalized as multiples of the median. Ratios of serum placental growth factor (PIGF) and soluble fms-like tyrosine kinase 1 (sFLT-1) were also measured, and transabdominal ultrasonography was conducted for subjects in the prospective cohort. Binary logistic regression models for PE prediction were constructed and tested. RESULTS: Our results revealed that the women with PE showed significant alterations in serum cfRNA profiles from early pregnancy onward and before the onset of PE symptoms. Compared with PIGF/sFLT-1 measurement and ultrasonographic imaging, cfRNA test can detect PE at a very early stage of pregnancy. The predictive model exhibited the best performance at gestation week 32, with a detection rate of 100%. At 12 weeks of gestation, the model still manifested an area under curve (AUC) of 0.9144, and sensitivity of 1.0000. If combined with clinical parameters and ultrasonographic indicators, the model can achieve the highest AUC for PE prediction at early gestation. CONCLUSION: Measurement of cfRNA can be used to effectively predict PE with high performance, providing an additional method for monitoring PE throughout the course of pregnancy.

Maternal prediabetes as a risk factor of preeclampsia and placental dysfunction in pregnant female Sprague-Dawley rats.

BACKGROUND: Prediabetes (PD) is associated with intermediate hyperglycaemia, dyslipidaemia, reduced nitric oxide (NO) bioavailability and moderate hypertension. All these factors are risk factor for preeclampsia (PE). However, the effects of the PD on placental function have not been shown. Accordingly, this study sought to investigate a possible link between maternal PD and the risk of developing PE. METHODS: Pregnant female Sprague-Dawley rats (N = 18) were divided into normal, preeclamptic and prediabetic groups (n = 6 in each group) to study the effects of maternal PD on placenta function over the period of 19 days. Blood glucose and blood pressure were measured on gestational day (GND) 0, 9 and 18. Placental vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) mRNA expression were measured terminally. Data were analysed using ANOVA followed by the Tukey-Kramer post hoc test. Values of p < .05 were used to indicate statistical significance. RESULTS: Maternal PD and PE significantly increased blood glucose, decrease NO concentration and increase in MAP by comparison to the normal pregnant control group. Maternal PD significantly decreased VEGF, PlGF mRNA expression with a slight increase in sFlt-1 mRNA expression comparison to the normal pregnant control group. CONCLUSIONS: Maternal PD is associated with placental dysfunction due to impaired glucose handling, endothelial dysfunction and an imbalance in angiogenic and antiangiogenic factors. Therefore, maternal PD is a risk factor of PE.

People with prediabetes (PD) are at risk of developing type 2 diabetes. Studies have shown that PD can cause blood vessel problems in both men and women. However, there have not been any studies on prediabetic pregnant women, so we do not know much about the pregnancy problems they might face. Looking into new factors related to blood vessel growth and health in PD could help us understand how to diagnose and manage PD during pregnancy. This could reduce the risk of problems similar to pre-eclampsia. Research in this area will help mothers and their doctors be more aware of the complications PD can cause during pregnancy. This could lead to fewer health problems and deaths for both mothers and babies linked to type 2 diabetes.