Accuracy of angiogenic biomarkers at ⩽20weeks' gestation in predicting the risk of pre-eclampsia: A WHO multicentre study.

OBJECTIVE: To assess the accuracy of angiogenic biomarkers to predict pre-eclampsia. DESIGN: Prospective multicentre study. From 2006 to 2009, 5121 pregnant women with risk factors for pre-eclampsia (nulliparity, diabetes, previous pre-eclampsia, chronic hypertension) from Argentina, Colombia, Peru, India, Italy, Kenya, Switzerland and Thailand had their serum tested for sFlt-1, PlGF and sEng levels and their urine for PlGF levels at ⩽20, 23-27 and 32-35weeks' gestation (index tests, results blinded from carers). Women were monitored for signs of pre-eclampsia, diagnosed by systolic blood pressure ⩾140mmHg and/or diastolic blood pressure ⩾90mmHg, and proteinuria (protein/creatinine ratio ⩾0.3, protein ⩾1g/l, or one dipstick measurement ⩾2+) appearing after 20weeks' gestation. Early pre-eclampsia was defined when these signs appeared ⩽34weeks' gestation. MAIN OUTCOME MEASURE: Pre-eclampsia. RESULTS: Pre-eclampsia was diagnosed in 198 of 5121 women tested (3.9%) of whom 47 (0.9%) developed it early. The median maternal serum concentrations of index tests were significantly altered in women who subsequently developed pre-eclampsia than in those who did not. However, the area under receiver operating characteristics curve at ⩽20weeks' gestation were closer to 0.5 than to 1.0 for all biomarkers both for predicting any pre-eclampsia or at ⩽34weeks' gestation. The corresponding sensitivity, specificity and likelihood ratios were poor. Multivariable models combining sEng with clinical features slightly improved the prediction capability. CONCLUSIONS: Angiogenic biomarkers in first half of pregnancy do not perform well enough in predicting the later development of pre-eclampsia.

Soluble fms-Like tyrosine kinase 1 (sFlt1), endoglin and placental growth factor (PlGF) in preeclampsia among high risk pregnancies.

BACKGROUND: Differences in circulating concentrations of antiangiogenic factors sFlt1 and soluble endoglin (sEng) and the pro-angiogenic growth factor PlGF are reported to precede the onset of preeclampsia weeks to months in low-risk pregnant women. The objective of this study was to investigate whether similar changes can be detected in pregnant women at high-risk to develop the syndrome. METHODS: This study is a secondary analysis of the NICHD MFMU trial of aspirin to prevent preeclampsia in high-risk pregnancies. Serum samples were available from 194 women with pre-existing diabetes, 313 with chronic hypertension, 234 with multifetal gestation, and 252 with a history of preeclampsia in a previous pregnancy. Samples collected across pregnancy were analyzed in a blinded fashion for sFlt1, sEng and PlGF. RESULTS: The odds of developing preeclampsia were significantly increased among women with multiple fetuses for each 2-fold elevation in sFlt1, sEng and the ratio of angiogenic factors (e.g. OR 2.18, 95% CI 1.46-3.32), and significantly decreased for each 2-fold elevation in circulating PlGF (OR 0.50, 95% CI 0.30-0.82) between 7 and 26 weeks' gestation. Cross-sectional analysis of the angiogenic factors across gestation showed significant differences during the third trimester in women who develop preeclampsia compared with appropriate controls in all high-risk groups. However, when data were examined in relation to the gestational week when preeclampsia was diagnosed only sFlt1 was significantly higher 2 to 5 weeks before the clinical onset of preeclampsia and only in women with previous preeclampsia. CONCLUSIONS: The pattern of elevated concentrations of sFlt1 and sEng, and low PlGF in high-risk pregnant subjects who develop preeclampsia is similar to that reported in low-risk pregnant women. However, differences in these factors among high-risk women who do and do not develop preeclampsia are modest, and do not appear to be clinically useful predictors in these high-risk pregnant women.

Effect of smoking on circulating angiogenic factors in high risk pregnancies.

OBJECTIVE: Changes in maternal concentrations of the anti-angiogenic factors, soluble fms-like tyrosine kinase 1 (sFlt1) and soluble endoglin (sEng), and the pro-angiogenic placental growth factor (PlGF) precede the development of preeclampsia in healthy women. The risk of preeclampsia is reduced in women who smoke during pregnancy. The objective of this study was to investigate whether smoking affects concentrations of angiogenic factors (sFlt1, PlGF, and sEng) in women at high risk for developing preeclampsia. STUDY DESIGN: We performed a secondary analysis of serum samples from 993 high-risk women (chronic hypertension, diabetes, multifetal gestation, and previous preeclampsia) in a preeclampsia prevention trial. sFlt1, sEng and PlGF were measured in serum samples obtained at study entry, which was prior to initiation of aspirin (median 19.0 weeks' [interquartile range of 16.0-22.6 weeks']). Smoking status was determined by self-report. RESULTS: sFlt1 was not significantly different in smokers from any high-risk groups compared to their nonsmoking counterparts. PlGF was higher among smokers compared to nonsmokers among diabetic women (142.7 [77.4-337.3] vs 95.9 [48.5-180.7] pg/ml, p = 0.005) and women with a history of preeclampsia (252.2 [137.1-486.0] vs 152.2 [73.6-253.7] pg/ml, p = 0.001). sEng was lower in smokers with multifetal gestations (5.8 [4.6-6.5] vs 6.8 [5.5-8.7] ng/ml, p = 0.002) and trended lower among smokers with diabetes (4.9 [3.8-5.6] vs 5.3 [4.3-6.3] ng/ml, p = 0.05). Smoking was not associated with a lower incidence of preeclampsia in any of these groups. CONCLUSIONS: In certain high-risk groups, smoking is associated with changes in the concentrations of these factors towards a pro-angiogenic direction during early pregnancy; however, there was no apparent association between smoking and the development of preeclampsia in our cohort.

Influence of maternal asthma and asthma severity on newborn morphometry.

OBJECTIVE: To determine if maternal asthma or asthma severity affects newborn morphometry. STUDY DESIGN: A secondary analysis was performed on data collected in a multicenter prospective observational cohort study of asthma in pregnancy. Patients enrolled included women with asthma stratified by severity of disease and controls. Asthma severity was defined according to the classification proposed by the National Asthma Education Program (NAEP) Report of the Working Group on Asthma and Pregnancy, modified to include medication requirements. Newborn morphometry measurements included birth weight (BW) and multiples of the median birth weight (BW-MOM), head circumference (HC), length (L), HC:BW ratio, and ponderal index (PI). RESULTS: Of 2480 patients there were 828 nonasthmatic controls, 828 with mild, 775 with moderate, and 49 with severe disease. Comparing all groups, there were statistically significant differences in maternal age (p < .001), race (p = .005), parity (p = .006), prepregnancy weight (p = .028), and medical care source (p = .001), with the severe asthma group having the highest mean maternal age (25.7 years), and proportion of African Americans (71.4%), proportion of multiparous patients (63.3%), and proportion of patients receiving government assistance (85.7%). When the control group was excluded from the comparisons, differences in prepregnancy weight and medical care source were no longer significant. BW-MOM and L did not differ between groups. The HC:BW ratio increased with asthma severity (p = .029) and was increased compared to controls (p = .010). This remained significant after controlling for confounding variables (both p <.001). HC was statistically significantly different between all groups (p = .032), as well as among women with varying degrees of asthma severity (p = .013), which was not clinically significant. After covariates adjustment, HC was not significantly different among all groups (p = .228), nor the asthma groups (p = .144). CONCLUSION: Asthma severity is associated with an increased HC:BW ratio. Severity was not found to impact HC, BW-MOM, L, or PI independently. However, the magnitudes of the effects were too small to suggest a clinically significant effect of asthma on neonatal morphometry in this large prospectively studied sample.

Angiogenic dysfunction in molar pregnancy.

OBJECTIVE: Molar pregnancy is associated with very early-onset preeclampsia. Since excessive circulating antiangiogenic factors may play a pathogenic role in preeclampsia, we hypothesized that molar placentas produce more antiangiogenic proteins than normal placentas. STUDY DESIGN: This retrospective case-control study used a semiquantitative immunohistochemical technique to compare histologic sections of molar placentas to normal controls. Tissue slides were treated with 2 antisera: one recognized the antiangiogenic markers fms-like tyrosine kinase receptor 1 (Flt1) and its soluble form (sFlt1), while the other recognized vascular endothelial marker CD31. Stain intensity was graded from 1+ (strong focal staining) to 4+ (91-100% staining). RESULTS: Molar placentas (n = 19) showed significantly more staining than controls (n = 16) for Flt/sFlt1 (P < .0001). CONCLUSION: There was a significant difference in Flt1/sFlt1 immunostaining intensity when molar placentas were compared to controls. This supports a hypothesis that the phenotype of preeclampsia in molar pregnancy may result from trophoblasts overproducing at least 1 antiangiogenic protein.

Maternal plasma concentrations of the soluble tumor necrosis factor receptor 2 are increased prior to the diagnosis of preeclampsia.

OBJECTIVE: Soluble receptor levels of tumor necrosis factor (sTNF-R)-1 and -2 are increased during preeclampsia. We postulated the increase preceded overt disease. STUDY DESIGN: Archived plasma from the Eunice Kennedy Shriver National Institute of Child Health and Human Development aspirin to prevent preeclampsia in high risk women trial were used to measure serial sTNF-R1 and sTNF-R2 (enrollment, 24-28 week's gestation) in 986 women (577 also sampled at 34-38 weeks). RESULTS: Preeclampsia incidence was 21.2%. sTNF-R2 levels were higher at enrollment (P = .02) and weeks 24-28 (P = .01) in women who eventually developed preeclampsia. The magnitude of increase from baseline of both receptors was significantly greater in women who developed preeclampsia in the future. Women with week 24-28 sTNF-R2 levels in the highest quartile had significantly increased odds to develop preeclampsia (P = .03 vs quartile 1). This association was observed in the placebo but not the aspirin arm (P