Prevention of Preeclampsia and Intrauterine Growth Restriction With Aspirin Started in Early Pregnancy: A Meta-Analysis

[Comparative analysis of mice models for preeclampsia]

Preeclampsia is a multifactorial disease of pregnancy. It is a major cause of maternal and perinatal mortality and morbidity and is defined by the de novo onset of hypertension and proteinuria after the 20th week of pregnancy. This pathology manifests during the early stages of pregnancy, making it hard to predict and very difficult to study in humans (presymptomatic phase and lack of tissues access). Animal models are therefore necessary to study the physiopathology of preeclampsia, however, since this pathology is specifically human, there are no spontaneous models. Animal models have thus been engineered. In this review, the models obtained in mice are described and compared. These models are essential for the development of new therapeutic strategies.

Risk for recurrence of preeclampsia and outcome of subsequent pregnancy in women with preeclampsia in their first pregnancy

OBJECTIVE

To assess subsequent pregnancy outcome and to identify risk factors for recurrence of preeclampsia (PET) in women with PET in their first pregnancy.

METHODS

A retrospective cohort study of all nulliparous women diagnosed with PET during the years 1996-2008 (PET group, N = 600). Outcome of subsequent pregnancy was compared with a control group of nulliparous women without PET matched by maternal age in a 3:1 ratio (N = 1800).

RESULTS

Subsequent pregnancies in the PET group were characterized by a higher rate of preterm delivery at less than 37 and 34 weeks (15.2% vs. 5.7%, p < 0.001 and 3.8% vs. 0.8%, p < 0.001, respectively), placental abruption (1.7% vs. 0.2%, p = 0.004), IUGR (2.8% vs. 0.9%, p = 0.016), and PET (5.9% vs. 0.8%, p < 0.001). Risk factors for PET and adverse outcome in the subsequent pregnancy included: PET complicated by placental abruption in the index pregnancy (OR = 10.8, 95%-CI = 1.8-34.6), PET requiring delivery prior to 34 weeks in the index pregnancy (OR = 6.5, 95%-CI = 1.6-22.5), chronic hypertension (OR = 5.3, 95%-CI = 1.9-12.7), and maternal age > 35 (OR = 4.3, 95%-CI = 1.2-20.5).

CONCLUSION

PET in the first pregnancy is independently associated with an increased risk for adverse pregnancy outcome and recurrence of PET in the subsequent pregnancy in a manner that is related to the severity of PET in the first pregnancy.

The underestimation of immaturity in late preterm infants

PURPOSE

Late preterm infants with gestational ages between 34 0/7 and 36 6/7 weeks are known to be at higher risk of mortality and morbidity than term newborns. This study aims to investigate the nature and frequency of neonatological complications in the late preterm population resulting in neonatal intensive care unit admissions as well as to draw obstetrical conclusions from the results.

METHODS

Neonatological outcomes of 893 consecutively born late preterm infants were evaluated and classified by the frequency of occurrence in relation to potential maternal or fetal risk factors.

RESULTS

Out of 893 late preterm infants, 528 (59.1 %) required intensive neonatal care. The incidence of apnea and bradycardia, the occurrence of feeding difficulties and the requirement of continuous positive airway pressure (CPAP) were inversely proportional to gestational age (p < 0.001). Gestational diabetes of the mother was more frequently associated with hypoglycemia (p < 0.001), but showed a reduced risk of hypothermia (p < 0.001). Small for gestational age neonates had a significantly lower rate of respiratory disorders (p < 0.001), but were more often affected by feeding difficulties (p < 0.01). Normal vaginal delivery had a significant advantage with regard to the necessity of CPAP (p < 0.01) and the occurrence of feeding difficulties (p < 0.05). Infants born by cesarean section were at higher risk of hypoglycemia (p < 0.001), but at lower risk of hyperbilirubinemia (p < 0.001).

CONCLUSIONS

The high risk of a problematic neonatological outcome in late preterms requires fundamental reconsideration. All efforts to prolong a pregnancy should be made beyond the 34th week of gestation.

Preeclampsia: multiple approaches for a multifactorial disease

Preeclampsia is a pregnancy-specific disorder characterized by hypertension and excess protein excretion in the urine. It is an important cause of maternal and fetal morbidity and mortality worldwide. The disease is almost exclusive to humans and delivery of the pregnancy continues to be the only effective treatment. The disorder is probably multifactorial, although most cases of preeclampsia are characterized by abnormal maternal uterine vascular remodeling by fetally derived placental trophoblast cells. Numerous in vitro and animal models have been used to study aspects of preeclampsia, the most common being models of placental oxygen dysregulation, abnormal trophoblast invasion, inappropriate maternal vascular damage and anomalous maternal-fetal immune interactions. Investigations into the pathophysiology and treatment of preeclampsia continue to move the field forward, albeit at a frustratingly slow pace. There remains a pressing need for novel approaches, new disease models and innovative investigators to effectively tackle this complex and devastating disorder.

Screening for pre-eclampsia using serum placental growth factor and endoglin with Down's syndrome Quadruple test markers

OBJECTIVE

To estimate the pre-eclampsia screening performance of placental growth factor (PlGF) and endoglin with second-trimester Quadruple test markers used for antenatal Down's syndrome screening.

METHODS

A nested case-control study of 88 pregnant women with known early second-trimester Down's syndrome Quadruple test marker levels who subsequently developed pre-eclampsia and 275 unaffected controls. Frozen maternal serum samples were thawed and assayed for PlGF and endoglin. Monte Carlo simulation was used to estimate the pre-eclampsia screening performance of a pre-eclampsia detection algorithm using the Quadruple test markers with or without the addition of PlGF and/or endoglin.

RESULTS

Median PlGF was 33% lower (95% confidence interval 24-41%) and endoglin 31% (20-43%) higher in pre-eclampsia than in unaffected pregnancies. Adding PlGF to the Quadruple test markers increased the pre-eclampsia detection rate from 34% to 45% at a 5% false-positive rate - it increased it to 43% with endoglin and to 50% with both. The corresponding estimates for early pre-eclampsia (before 36 weeks' gestation) were a few percentage points higher (48%, 48% and 55% respectively). Including information on parity, pre-eclampsia in a previous pregnancy, family history (woman's mother) and assuming a pre-eclampsia prevalence of 2%, the detection rates for a 5% false-positive rate were 39% with the Quadruple test markers, 48% with addition of endoglin, 49% with addition of PlGF, and 54% with addition of both.

CONCLUSIONS

Adding PlGF to the Quadruple test Down's syndrome screening markers improves pre-eclampsia screening performance. There is a modest extra benefit in also adding the measurement of endoglin.

Maternal serum placental growth hormone at 11-13 weeks' gestation in pregnancies delivering small for gestational age neonates

OBJECTIVE

To investigate whether the maternal serum concentration of human placental growth hormone (PGH) at 11-13 weeks' gestation is altered in pregnancies that deliver small for gestational age (SGA) neonates.

METHODS

Maternal serum concentration of PGH was measured in 60 cases that subsequently delivered SGA neonates in the absence of preeclampsia and compared to 120 non-SGA controls.

RESULTS

In the SGA group, compared to the non-SGA group, there was no significant difference in the median PGH MoM (0.95 MoM, IQR 0.60-1.30 vs. 1.00 MoM, IQR 0.70-1.30, p = 0.97). There was no significant association between PGH MoM and birth weight percentile in either the SGA (p = 0.72) or in the non-SGA group (p = 0.63).

CONCLUSION

Maternal serum PGH at 11-13 weeks' gestation is unlikely to be a useful biochemical marker for early prediction of SGA.

Recurrence and severity of abnormal pregnancy outcome in patients treated by low-molecular-weight heparin: a prospective pilot study

OBJECTIVE

This prospective pilot study assesses the recurrence rate and severity of abnormal pregnancy outcome (APO), excluding early pregnancy complications, in pregnant patients, without acquired thrombophilia, treated by prophylactic doses of low-molecular-weight heparin (LMWH), independently from their congenital thrombophilic condition.

METHODS

We recruited a cohort of 128 pregnant patients with previous APO; 100 of whom with APO and intrauterine growth restriction (IUGR) and 28 with maternal APO only. LMWH treatment was started at recruitment. Composite cross-over recurrence rate IUGR, gestational hypertension, preeclampsia, help syndrome, abruptio placenta were analyzed. The main outcome measure was severe APOs with iatrogenic delivery ≤ 32 weeks of gestation.

RESULTS

Median gestational age at LMWH treatment was 20 weeks. Severe APO decreased in treated pregnancies from 45% to 4% (relative risk = 0.3, confidence interval 95% = 0.2-0.8). This value was not significantly different in thrombophilic and nonthrombophilic patients. When severe and minor complications were analyzed altogether, the recurrence rate was 28%. In patients with APO and fetal growth restriction (FGR) in the index pregnancy, newborn weights were significantly better in the treated pregnancy: 1090 g (1035-1145) vs. 850 g (535-1200), p < 0.01.

CONCLUSIONS

Prophylactic regimen of LMWH significantly reduced the recurrence rate of severe composite APO in pregnancies affected in the index pregnancy by APO and FGR or small for gestational age newborns. This result was independent from the patients' inherited thrombophilic conditions.

Early administration of low-dose aspirin for the prevention of preterm and term preeclampsia: a systematic review and meta-analysis

OBJECTIVE

To compare the effect of early administration of aspirin on the risk of preterm and term preeclampsia.

METHOD

A systematic review and meta-analysis of randomized controlled trials were performed. Women who were randomized to low-dose aspirin or placebo/no treatment at or before 16 weeks of gestation were included. The outcomes of interest were preterm preeclampsia (delivery <37 weeks) and term preeclampsia. Pooled relative risks (RR) with their 95% confidence intervals (CI) were computed.

RESULTS

The search identified 7,941 citations but only five trials on a combined total of 556 women fulfilled the inclusion criteria. When compared to controls, aspirin initiated ≤16 weeks of gestation was associated with a major reduction of the risk of preterm preeclampsia (RR 0.11, 95% CI 0.04-0.33) but had no significant effect on term preeclampsia (RR 0.98, 95% CI 0.42-2.33).

CONCLUSION

Low-dose aspirin administrated at or before 16 weeks of gestation reduces the risk of preterm but not term preeclampsia.

Accuracy of circulating placental growth factor, vascular endothelial growth factor, soluble fms-like tyrosine kinase 1 and soluble endoglin in the prediction of pre-eclampsia: a systematic review and meta-analysis

BACKGROUND

Biomarkers have been proposed for identification of women at increased risk of developing pre-eclampsia.

OBJECTIVES

To investigate the capacity of circulating placental growth factor (PlGF), vascular endothelial growth factor (VEGF), soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin (sENG) to predict pre-eclampsia.

SEARCH STRATEGY

Medline and Embase through October 2010 and reference lists of reviews, without constraints.

SELECTION CRITERIA

We included original publications on testing of PlGF, VEGF, sFLT1 and sENG in serum or plasma of pregnant women at <30 weeks of gestation and before clinical onset of pre-eclampsia.

DATA COLLECTION AND ANALYSIS

Two reviewers independently identified eligible studies, extracted descriptive and test accuracy data and assessed methodological quality. Summary estimates of discriminatory performance were obtained.

MAIN RESULTS

We included 34 studies. Concentrations of PlGF (27 studies) and VEGF (three studies) were lower in women who developed pre-eclampsia: standardised mean differences (SMD) -0.56 (95% CI -0.77 to -0.35) and -1.25 (95% CI -2.73 to 0.23). Concentrations of sFLT1 (19 studies) and sENG (ten studies) were higher: SMD 0.48 (95% CI 0.21-0.75) and SMD 0.54 (95% CI 0.24-0.84). The summary diagnostic odds ratios were: PlGF 9.0 (95% CI 5.6-14.5), sFLT1 6.6 (95% CI 3.1-13.7), sENG 4.2 (95% CI 2.4-7.2), which correspond to sensitivities of 32%, 26% and 18%, respectively, for a 5% false-positive rate.

AUTHOR'S CONCLUSIONS

PlGF, sFLT1 and sENG showed modest but significantly different concentrations before 30 weeks of gestation in women who developed pre-eclampsia. Test accuracies of all four markers, however, are too poor for accurate prediction of pre-eclampsia in clinical practice.

Extracellular nucleic acids in maternal circulation as potential biomarkers for placental insufficiency

Since the placenta is being continuously remodeled during normal placental development, extracellular nucleic acids of both fetal and placental origin, packed into either trophoblast-derived apoptotic bodies or shedding syncytiotrophoblast microparticles, may be detected in maternal circulation during the course of normal gestation. Placental-insufficiency-related pregnancy complications have been shown to be associated with excessive placental trophoblast apoptosis and shedding of placenta debris. Recent advances in the field are reviewed with a focus on the diagnostic potential of particular molecular biomarkers and their eventual implementation in the currently used predictive and diagnostic algorithms for placental-insufficiency-related pregnancy complications.

Preconception counseling

The preconception counseling visit is an ideal time to evaluate the patient and her future expectations regarding pregnancy. In fact at every patient encounter, whether for acute or chronic care, consideration should be given to any woman who, although not pregnant, may become pregnant, and what effect each ordered procedure, laboratory examination, or medication prescription might have on her or her fetus. If the primary reason for the office visit is preconception counseling there are a few specific components that should be discussed besides a complete history and physical examination.

Low-molecular-weight heparin added to aspirin in the prevention of recurrent early-onset pre-eclampsia in women with inheritable thrombophilia: the FRUIT-RCT

BACKGROUND

Early-onset hypertensive disorders (HD) of pregnancy and small-for-gestational age infants (SGA) are associated with placental vascular thrombosis, these often recur and are also associated with inheritable thrombophilia. Aspirin reduces the recurrence risk.

OBJECTIVES

Adding low-molecular-weight heparin (LMWH) to aspirin at < 12 weeks gestation reduces the recurrence of HD in women with previous early-onset HD (pre-eclampsia, hemolysis, elevated liver enzymes and low platelets [HELLP] syndrome and eclampsia) and/or SGA, in the context of inheritable thrombophilia without antiphospholipid antibodies.

PATIENTS/METHODS

In a multicenter randomized control trial (RCT), 139 women included were< 12 weeks gestation.

INCLUSION CRITERIA

previous delivery< 34 weeks gestation with HD and/or SGA; inheritable thrombophilia (protein C deficiency, protein S deficiency, activated protein C resistance, factor V Leiden heterozygosity and prothrombin gene G20210A mutation heterozygosity); and no antiphospholipid antibodies detected.

INTERVENTION

either daily LMWH (dalteparin, 5000 IU weight-adjusted dosage) with aspirin 80 mg or aspirin 80 mg alone.

MAIN OUTCOME MEASURES

PRIMARY OUTCOMES

recurrent HD onset (i) < 34 weeks gestation and (ii) irrespective of gestational age.

SECONDARY OUTCOMES

recurrent SGA, preterm birth, maternal/neonatal hospitalization, spontaneous abortion and individual HD. Analysis by intention-to-treat.

RESULTS

Low-molecular-weight heparin with aspirin reduced recurrent HD onset < 34 weeks gestation (risk difference [RD] 8.7%: confidence interval [CI] of RD 1.9–15.5%; P = 0.012; number needed to treat [NNT] 12). Recurrent HD irrespective of gestational age was not different between the arms. No women withdrew as a result of adverse effects.

TRIAL REGISTRATION

http://www.isrctn.org) (isrctn87325378).

CONCLUSIONS

Adding LMWH to aspirin at < 12 weeks gestation reduces recurrent HD onset < 34 weeks gestation in women with inheritable thrombophilia and prior delivery for HD/SGA <34 weeks. However, close monitoring of the mother and fetus remains important throughout pregnancy.

The possible options for the prevention of preeclampsia

This review summarizes the possible options for the prevention of preeclampsia based on important factors of patomechanism. The effects of antioxidants have been described in numerous clinical researches based on the oxidative hypothesis. Another important factor is the change of nitric oxide activity. Nitric oxide donors are able to compensate the symptoms of preeclampsia. The inverse relationship between the calcium intake and gestational hypertension has been known for a long time. The calcium supplementation seems to be a good opportunity to prevent preeclampsia. With low molecular weight heparins we can intervene in the patomechanisms of preeclampsia by antithrombocyte effects, vasoactive properties and impact on throphoblast cell morphology and differentiation. Thrombocyte aggregation inhibitors were examined in number of studies because they reduced thromboxane mediated vasoconstriction and inhibited placental thrombosis. Several studies verify whether prophylaxis with low molecular weight heparins and low dose aspirin could improve pregnancy outcome in preeclampsia. Orv. Hetil., 2012, 153, 144–151.

Prevention of pre-eclampsia with low-dose aspirin or vitamins C and E in women at high or low risk: a systematic review with meta-analysis

The aim of this study is to review literature about the efficacy of low dose aspirin (LDA) and vitamins C/E (VCE) to prevent pre-eclampsia in women at high and low risk. Randomized clinical trials were included and stratified for high and low risk women. Inclusion criteria were: assignment of patients in treated or placebo groups, definition of pre-eclampsia according to the guidelines of the International Society for the Study of Hypertension in Pregnancy. Exclusion criteria were: omitting at least one of the inclusion criteria, trials involving women with pre-eclampsia at trial entry, studies investigating hypertensive disorders other than pre-eclampsia, prophylaxis of intrauterine growth restriction with low-dose aspirin or vitamins C/E, non-randomized studies and data reported in graphs or percentages. The incidence of pre-eclampsia, perinatal outcomes and adverse effects attributable to LDA and VCE were compared between treated women and placebo. Inter-studies heterogeneity was tested. P<0.05 was considered significant. pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated. PRISMA guidelines were followed. Fifteen studies were pooled. LDA did not decrease the incidence of pre-eclampsia in high-risk (396/5025 - 8% vs placebo: 464/5027 - 9%; P=0.05; OR: 0.72; 95% CI: 0.51-1.00) and low-risk (137/4939 - 3% vs placebo: 166/4962 - 3%; P=0.10; OR: 0.82; 95% CI: 0.65-1.04) women. Similarly, VCE did not reduce the incidence of pre-eclampsia in high-risk (VCE: 250/1744 - 14% vs placebo: 275/1741 - 16%; P=0.24; OR: 0.84; 95% CI: 0.63-1.12) and low-risk (VCE: 56/935 - 6% vs placebo 47/942 - 5%; P=0.57; OR: 1.20; 95% CI: 0.82-1.75) women. In high-risk women, other hypertensive disorders were more frequent in VCE (121/1692 - 7%) than placebo (79/1693 - 5%; P=0.002). Perinatal outcomes were not improved by LDA or VCE.

CONCLUSION

there is no evidence to support the administration of LDA or VCE to prevent pre-eclampsia.

Angiogenic growth factors in the diagnosis and prediction of pre-eclampsia

The pathogenesis of pre-eclampsia is still not completely known; however, in the recent decade, there have been tremendous research efforts leading to impressive results highlighting the role of a disturbed angiogenic balance as one of the key features of the disease. Numerous studies have shown the key role of the placenta in the pathogenesis of pre-eclampsia. A shift in the sFlt-1 (soluble Fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio is associated with the disease. Although pre-eclampsia seems to be a clearly defined disease, clinical presentation, and particularly the dynamics of the clinical course, can vary enormously. The only available tools to diagnose pre-eclampsia are blood pressure measurement and urine protein sampling. However, these tools have a low sensitivity and specificity regarding the prediction of the course of the disease or maternal and perinatal outcomes. The only cure for the disease is delivery, although a timely diagnosis helps in decreasing maternal and fetal morbidity and mortality. The sFlt1/PlGF ratio is able to give additional valuable information on the status and progression of the disease and is apt to be implemented in the diagnostic algorithm of pre-eclampsia. In the present review, we aim to provide an overview of the vast literature on angiogenesis and anti-angiogenesis factors in pre-eclampsia that have been published over the last decade. We introduce work from basic research groups who have focused on the pathophysiological basis of the disease. Furthermore, we review studies with a clinical focus in which the sFlt-1/PlGF ratio has been analysed along with other candidates for routine clinical assessment of pre-eclampsia.

Uterine artery Doppler and biochemical markers (PAPP-A, PIGF, sFlt-1, P-selectin, NGAL) at 11 + 0 to 13 + 6 weeks in the prediction of late (> 34 weeks) pre-eclampsia

OBJECTIVE

To determine the performance of screening for late pre-eclampsia (PE) by maternal characteristics, uterine artery Doppler and a set of biochemical markers at 11 + 0 to 13 + 6 weeks' gestation.

METHODS

Prospectively enrolled women at 11 + 0 to 13 + 6 weeks. Maternal characteristics, highest UtA pulsatility index and serum placental biomarkers including pregnancy-associated plasma protein-A, placental growth factor, soluble fms-like tyrosine kinase 1, P-selectin and neutrophil gelatinase-associated lipocalin were recorded.

RESULTS

The rate of PE was 2.5% (13/528). Four (0.8%) had severe PE. A combined screening model that included placental growth factor, soluble fms-like tyrosine kinase 1 and neutrophil gelatinase-associated lipocalin could detect 77% of PE at a 10% false-positive rate. Mean risk for mild PE was 8.8% ± 6.4, mean risk for severe PE was 38.6% ± 4.3. Mean risk for controls was 2% ± 4.1.

CONCLUSION

This combination of maternal biochemical variables in the first trimester can detect a consistent number of late PE. Further studies on a new and independent series of data could confirm the presented results.

[News on antithrombotic therapy and pregnancy]

OBJECTIVES

State of the art of antithrombotics and their use recommendations during pregnancy.

METHODS

A review

RESULTS

Aspirin and heparins remain the safest molecules during pregnancy, and oral anticoagulants are still used for mechanical valves. Heparinoids are the methods of choice in case of heparin-induced thrombopenia but other molecules could find their place: fondaparinux at first and possibly the direct thrombin inhibitors. Thrombolysis may be used in case of life-threatening incident. At present, the new oral forms can not be used during pregnancy

CONCLUSIONS

During pregnancy, all antithrombotics, except the oral forms, can be used, but the low molecular weight heparins replacing the unfractionated ones in the treatment and prevention of venous thromboembolism remain the treatment of choice.

Stability of first trimester placental growth factor in serum and whole blood

BACKGROUND

Placental growth factor (PlGF) is a proposed first-trimester screening marker for pre-eclampsia. This study investigates the stability of PlGF in serum and whole blood at typical routine storage temperatures.

METHODS

Serum pools were stored at refrigerator temperature, room temperature or 30 °C for up to 30 days, or exposed to up to six freeze-thaw cycles. Whole blood was stored at room temperature or 30 °C for up to 6 days. PlGF was quantified using a DELFIA Xpress analyser.

RESULTS

Placental growth factor levels increased over time, seemingly because of the dissociation of PlGF bound to a soluble binding protein, sFlt-1. Increase was slow in serum at refrigerator temperature, remaining stable (less than 10% change from start point) for at least 30 days. At room temperature PlGF was stable for 3.3 days and at 30 °C for 1 day. Serum PlGF remained stable for at least six freeze-thaw cycles. In whole blood, instability was worse, being stable for only 19.4 h at room temperature and just 3.3 h at 30 °C.

CONCLUSION

Routine screening of sample handling requires careful monitoring. However, no extra precautions need to be taken when PlGF is used for pre-eclampsia screening run alongside existing first trimester aneuploidy screening programs that include hCGβ.

Maternal plasma concentrations of angiogenic/anti-angiogenic factors are of prognostic value in patients presenting to the obstetrical triage area with the suspicion of preeclampsia

OBJECTIVE

To determine whether maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and -2 could identify patients at risk for developing preeclampsia (PE) requiring preterm delivery.

STUDY DESIGN

Patients presenting with the diagnosis "rule out PE" to the obstetrical triage area of our hospital at <37 weeks of gestation (n = 87) were included in this study. Delivery outcomes were used to classify patients into four groups: I) patients without PE or those with gestational hypertension (GHTN) or chronic hypertension (CHTN) who subsequently developed PE at term (n = 19); II): mild PE who delivered at term (n = 15); III): mild disease (mild PE, GHTN, CHTN) who subsequently developed severe PE requiring preterm delivery (n = 26); and IV): diagnosis of severe PE (n = 27). Plasma concentrations of PlGF, sEng, sVEGFR-1 and -2 were determined at the time of presentation by ELISA. Reference ranges for analytes were constructed by quantile regression in our laboratory (n = 180; 1046 samples). Comparisons among groups were performed using multiples of the median (MoM) and parametric statistics after log transformation. Receiver operating characteristic curves, logistic regression and survival analysis were employed for analysis.

RESULTS

The mean MoM plasma concentration of PlGF/sVEGFR-1, PlGF/sEng, PlGF, sVEGFR-1 and -2, and sEng in Group III was significantly different from Group II (all p < 0.05). A plasma concentration of PlGF/sVEGFR-1 ≤ 0.05 MoM or PlGF/sEng ≤0.07 MoM had the highest likelihood ratio of a positive test (8.3, 95% CI 2.8-25 and 8.6, 95% CI 2.9-25, respectively), while that of PlGF ≤0.396 MoM had the lowest likelihood ratio of a negative test (0.08, 95% CI 0.03-0.25). The association between low plasma concentrations of PlGF/sVEGFR-1 (≤0.05 MoM) as well as that of PlGF/sEng (≤0.07 MoM) and the development of severe PE remained significant after adjusting for gestational age at presentation, average systolic and diastolic blood pressure, and a history of chronic hypertension [adjusted odds ratio (OR) = 27 (95% CI 6.4-109) and adjusted OR 30 (95% CI 6.9-126), respectively]. Among patients who presented <34 weeks gestation (n = 59), a plasma concentration of PlGF/sVEGFR-1 < 0.033 MoM identified patients who delivered within 2 weeks because of PE with a sensitivity of 93% (25/27) and a specificity of 78% (25/32). This cut-off was associated with a shorter interval-to-delivery due to PE [hazard ratio = 6 (95% CI 2.5-14.6)].

CONCLUSIONS

Plasma concentrations of angiogenic/anti-angiogenic factors are of prognostic value in the obstetrical triage area. These observations support the value of these biomarkers in the clinical setting for the identification of the patient at risk for disease progression requiring preterm delivery.

Mechanisms of enhanced vascular reactivity in preeclampsia

Preeclamptic women have enhanced blood pressure response to angiotensin II and extensive systemic vascular infiltration of neutrophils. Neutrophils release reactive oxygen species that might activate the RhoA kinase pathway to enhance vascular reactivity. We hypothesized that enhanced vascular reactivity in preeclampsia is attributed to neutrophil-mediated reactive oxygen species activation of the RhoA kinase pathway. Omental arteries were obtained at cesarean section and studied using a myograph system. We found that arteries of preeclamptic women had extensive infiltration of neutrophils and enhanced reactivity to angiotensin II. Treatment of arteries of normal pregnant women with reactive oxygen species or activated neutrophils enhanced vessel reactivity to angiotensin II mimicking preeclamptic vessels. Pretreatment with superoxide dismutase/catalase to quench reactive oxygen species or RhoA kinase inhibitor blocked enhanced responses in preeclamptic and normal vessels. Reactive oxygen species also enhanced vessel reactivity to norepinephrine, which was blocked by RhoA kinase inhibition. Treatment of arteries with reactive oxygen species increased RhoA kinase activity 3-fold, whereas culture of human vascular smooth muscle cells with angiotensin II and activated neutrophils or reactive oxygen species resulted in phosphorylation of key proteins in the RhoA kinase pathway. We conclude that enhanced vascular reactivity of omental arteries in preeclampsia is attributed to reactive oxygen species activation of the RhoA kinase pathway and that enhanced vascular reactivity is likely attributed to the infiltration of neutrophils. We speculate that neutrophil infiltration into systemic vasculature of preeclamptic women is an important mechanism for hypertension.

Maternal vitamin D and fetal growth in early-onset severe preeclampsia

OBJECTIVE

Recently, vitamin D deficiency has been associated with increased risks for preeclampsia and diagnosis of early-onset, severe preeclampsia (EOSPE). The purpose of this investigation was to examine the association between vitamin D levels and small-for-gestational age (SGA) in patients with EOSPE.

STUDY DESIGN

Patients with EOSPE were recruited, and demographics, outcomes, and plasma were collected. We assessed 25-hydroxyvitamin D (25[OH]D) by radioimmunoassay and reported our findings in nanograms per milliliter. Results were analyzed by Mann-Whitney U test and Spearman correlation and were reported as median (Q1-Q3).

RESULTS

In patients with EOSPE (n = 56), 25(OH)D was lower in patients with SGA (16.8 ng/mL; range, 8.9-23 ng/mL) vs normal fetal growth (25.3 ng/mL; range, 16-33 ng/mL; P = .02). 25(OH)D was correlated significantly with percentile growth at delivery (ρ = 0.31; P = .02).

CONCLUSION

Vitamin D is lower among patients with SGA in EOSPE than those without growth retardation. We suspect that vitamin D may impact fetal growth through placental mechanisms.

Pregnancy and stroke risk in women

Stroke, the sudden onset of brain dysfunction from a vascular cause, is one of the most common causes of long-term disability. Although rare during childbearing years, stroke is even more devastating when it occurs in a young woman trying to start a family. Pregnancy and the postpartum period are associated with an increased risk of ischemic stroke and intracerebral hemorrhage, although the incidence estimates have varied. There are several causes of stroke that are in fact unique to pregnancy and the postpartum period, such as preeclampsia and eclampsia, amniotic fluid embolus, postpartum angiopathy and postpartum cardiomyopathy. Data regarding these individual entities are scant. Most concerning is the lack of data regarding both prevention and acute management of pregnancy-related stroke. The purpose of this article is to summarize existing data regarding incidence, risk factors and potential etiologies, as well as treatment strategies for stroke in pregnancy.

Public health perspectives of preeclampsia in developing countries: implication for health system strengthening

OBJECTIVES

Review of public health perspectives of preeclampsia in developing countries and implications for health system strengthening.

METHODS

Literature from Pubmed (MEDLINE), AJOL, Google Scholar, and Cochrane database were reviewed.

RESULTS

The prevalence of preeclampsia in developing countries ranges from 1.8% to 16.7%. Many challenges exist in the prediction, prevention, and management of preeclampsia. Promising prophylactic measures like low-dose aspirin and calcium supplementation need further evidence before recommendation for use in developing countries. Treatment remains prenatal care, timely diagnosis, proper management, and timely delivery. Prevailing household, community, and health system factors limiting effective control of preeclampsia in these countries were identified, and strategies to strengthen health systems were highlighted.

CONCLUSION

Overcoming the prevailing challenges in the control of preeclampsia in developing countries hinges on the ability of health care systems to identify and manage women at high risk.

Turning the pyramid of prenatal care

The current approach to prenatal care, which involves visits at 16, 24, 28, 30, 32, 34 and 36 weeks and then weekly until delivery, was established 80 years ago. The high concentration of visits in the third trimester implies, firstly, that most complications occur at this late stage of pregnancy and, secondly, that most adverse outcomes are unpredictable during the first or even second trimester. This review presents evidence that many pregnancy complications can now be predicted at an integrated first hospital visit at 11-13 weeks by combining data from maternal characteristics and history with findings of biophysical and biochemical tests. It is therefore proposed that the traditional pyramid of care should be inverted with the main emphasis placed in the first rather than third trimester of pregnancy.

Colour Doppler ultrasound of spiral artery blood flow in the prediction of pre-eclampsia and intrauterine growth restriction

Pre-eclampsia and intrauterine growth restriction are responsible for significant maternal and fetal morbidity and mortality worldwide. Identifying pregnancies at highest risk for their development would allow increased surveillance in individual pregnancies and also allow therapeutic trials to decrease their incidences in the future. To date, multiple attempts to develop a screening test for these disorders have met with limited success. Proposed screening methods have included maternal serum biochemical parameters as well as ultrasonographic markers. Uterine artery Doppler, direct evaluation of the spiral arteries using colour and spectral Doppler, three-dimensional placental volume analysis and, most recently, three-dimensional power Doppler angiography have all been suggested. Although an adequate screening method remains elusive, advances in ultrasound technology have improved our ability to observe the pathophysiologic changes that occur with these conditions early in pregnancy, bringing us closer to a reproducible screening model.

Urinary Proteomics for Prediction of Preeclampsia

Preeclampsia is a major determinant of fetal and maternal morbidity and mortality. We used a proteomic strategy to identify urinary biomarkers that predict preeclampsia before the onset of disease. We prospectively collected urine samples from women throughout pregnancy. Samples from gestational weeks 12 to 16 (n=45), 20 (n=50), and 28 (n=18) from women who subsequently had preeclampsia develop were matched to controls (n=86, n=49, and n=17, respectively). We performed capillary electrophoresis online coupled to micro-time-of-flight mass spectrometry. Disease-specific peptide patterns were generated using support vector machine-based software. Candidate biomarkers were sequenced by liquid chromatography-tandem mass spectrometry. From comparison with nonpregnant controls, we defined a panel of 284 pregnancy-specific proteomic biomarkers. Subsequently, we developed a model of 50 biomarkers from specimens obtained at week 28 that was associated with future preeclampsia (classification factor in cases, 1.032±0.411 vs controls, −1.038±0.432; P <0.001). Classification factor increased markedly from week 12 to 16 to 28 in women who subsequently had preeclampsia develop (n=16; from −0.392±0.383 to 1.070±0.383; P <0.001) and decreased slightly in controls (n=16; from −0.647±0.437 to −1.024±0.433; P =0.043). Among the biomarkers are fibrinogen alpha chain, collagen alpha chain, and uromodulin fragments. The markers appear to predict preeclampsia at gestational week 28 with good confidence but not reliably at earlier time points (weeks 12–16 and 20). After prospective validation in other cohorts, these markers may contribute to better prediction, monitoring, and accurate diagnosis of preeclampsia.

Cell-free fetal nucleic acids as prenatal biomarkers

INTRODUCTION

Cell-free fetal nucleic acids in maternal plasma or serum have become important tools in the pursuance of new methods for non-invasive prenatal diagnosis, such as the determination of fetal blood groups and fetal gender. During these pioneering explorations, elevations in the concentration of these new-found biological analytes were noted in several pregnancy-related disorders, including preterm labor, pre-eclampsia and malimplantation. As these elevations appeared to occur before onset of clinical symptoms, it was proposed that such analyses might assist in screening for at-risk pregnancies. A major problem with these early studies is that they relied on the quantitation of Y-chromosome-specific gene sequences, and as such could be applied only in those cases where the fetus was male. Recent developments that might permit gender-independent analysis include epigenetic markers, as well as the analysis of cell-free placentally derived mRNA species.

AREAS COVERED

This article focuses specifically on prognostic markers, which enable at-risk pregnancies to be identified, allowing the modification of pregnancy management and in turn improvement of pregnancy outcome. The authors also provide their opinion on the progress and future challenges that lie ahead.

EXPERT OPINION

Accurate quantification of fetal nucleic acids and the specificity of these elevations for particular disorders remain controversial issues. Regarding the multifactorial etiology of some pregnancy disorders, the use of fetal nucleic acids as prenatal markers is restricted to well-defined high-risk groups.

Maternal serum adiponectin at 11-13 weeks of gestation in pregnancies delivering small for gestation neonates

OBJECTIVE

To investigate whether maternal serum levels of adiponectin in the first trimester are altered in pregnancies that subsequently deliver small for gestational age (SGA) neonates.

METHODS

Maternal serum adiponectin and pregnancy-associated plasma protein A (PAPP-A) were measured at 11-13 weeks' gestation in 50 singleton normotensive pregnancies that delivered SGA neonates and 300 non-SGA controls. The median adiponectin and PAPP-A levels in the SGA and non-SGA groups, expressed as multiple of the unaffected median (MoM), were compared.

RESULTS

The distribution of serum adiponectin was made gaussian by square root (sqrt) transformation. Regression analysis in the non-SGA group demonstrated that for sqrt adiponectin a significant independent contribution was provided by maternal age, weight, smoking status, African and South-Asian racial origin. Each value in the SGA and non-SGA group was then converted into a multiple of the non-SGA median (MoM) after adjustment for maternal characteristics. In the SGA group, compared to the non-SGA controls, median maternal serum PAPP-A was decreased (0.79, interquartile range [IQR] 0.54-1.06 MoM vs. 1.00, IQR 0.71-1.39 MoM) but adiponectin MoM was not significantly different (0.89, IQR 0.65-1.31 MoM vs. 1.02, IQR 0.70-1.29 MoM).

CONCLUSION

Maternal serum adiponectin is not a useful biochemical marker for early prediction of SGA.