Maternal and fetal modulators of lipid metabolism correlate with the development of preeclampsia

Recent Advances in the Prevention and Screening of Preeclampsia

Throughout the history of medicine, preeclampsia has remained an enigmatic field of obstetrics. In 2023, despite its prevalence and impact, preeclampsia's exact cause and effective treatment remain elusive; the current options are limited to delivery. The purpose of this review is to summarize the knowledge of the possible novel prophylactic therapies and screening methods for preeclampsia, thereby providing valuable insights for healthcare professionals and researchers. Aspirin and LMWH have already been widely used; meanwhile, calcium, vitamin D, and pravastatin show promise, and endothelin receptor antagonists are being explored. Stress reduction, dietary changes, and lifestyle modifications are also being investigated. Another interesting and fast-growing area is AI- and software-based screening methods. It is also key to find novel biomarkers, which, in some cases, are not only able to predict the development of the disease, but some of them hold promise to be a potential therapeutic target. We conclude that, while a definitive cure for preeclampsia may not be eligible in the near future, it is likely that the assessment and enhancement of preventive methods will lead to the prevention of many cases. However, it is also important to highlight that more additional research is needed in the future to clarify the exact pathophysiology of preeclampsia and to thus identify potential therapeutic targets for more improved treatment methods.

Preeclampsia: Linking Placental Ischemia with Maternal Endothelial and Vascular Dysfunction

Preeclampsia (PE), a hypertensive disorder, occurs in 3% to 8% of pregnancies in the United States and affects over 200,000 women and newborns per year. The United States has seen a 25% increase in the incidence of PE, largely owing to increases in risk factors, including obesity and cardiovascular disease. Although the etiology of PE is not clear, it is believed that impaired spiral artery remodeling of the placenta reduces perfusion, leading to placental ischemia. Subsequently, the ischemic placenta releases antiangiogenic and pro-inflammatory factors, such as cytokines, reactive oxygen species, and the angiotensin II type 1 receptor autoantibody (AT1-AA), among others, into the maternal circulation. These factors cause widespread endothelial activation, upregulation of the endothelin system, and vasoconstriction. In turn, these changes affect the function of multiple organ systems including the kidneys, brain, liver, and heart. Despite extensive research into the pathophysiology of PE, the only treatment option remains early delivery of the baby and importantly, the placenta. While premature delivery is effective in ameliorating immediate risk to the mother, mounting evidence suggests that PE increases risk of cardiovascular disease later in life for both mother and baby. Notably, these women are at increased risk of hypertension, heart disease, and stroke, while offspring are at risk of obesity, hypertension, and neurological disease, among other complications, later in life. This article aims to discuss the current understanding of the diagnosis and pathophysiology of PE, as well as associated organ damage, maternal and fetal outcomes, and potential therapeutic avenues. © 2021 American Physiological Society. Compr Physiol 11:1315-1349, 2021.

No effect of a low dose of metformin on the lipid profile, body mass index and weight gain in pregnant women with obesity: A randomized trial

OBJECTIVE

Evaluate the lipid profile, Body Mass Index (BMI) and weight gain of pregnant women with obesity and the effect of a low dose (1000 mg/day) of metformin hydrochloride on these parameters.

METHODS

A randomized clinical trial was performed from October 31th, 2014 to January 25th, 2018 with pregnant women diagnosed with obesity by arrival BMI ≥ 30.0 kg/m². The participants were randomized into two groups: metformin and control. All pregnant women received standard prenatal follow-up and the same instructions of diet and physical exercise. Laboratory tests were performed at three different times: first moment with gestational age (GA) < 20 weeks, second (GA 24-28 weeks) and third (GA 32-34 weeks) measuring maternal serum levels of total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides (TG) as well as weight gain and BMI were monitored.

RESULTS

A total of 424 pregnant women with obesity were evaluated. Of these, 218 (51.41%) composed the control group and 206 (48.59%) the metformin group. There was no difference of lipid profile, BMI and weight gain values between groups during the 1st, 2nd and 3rd evaluation moments. A significant difference was observed, only in the BMI, HDL and TG values from 1st to 3rd evaluation moments.

CONCLUSION

Low dose (1000 mg/day) of the drug showed no effect on the lipid profile, BMI and weight gain in pregnant women with obesity in metformin group during the evaluation moments.

Proteomic analysis of human placental syncytiotrophoblast microvesicles in preeclampsia

Background

Placental syncytiotrophoblast microvesicles (STBM) are shed into the maternal circulation during normal pregnancy. STBM circulate in significantly increased amounts in preeclampsia (PE) and are considered to be among contributors to the exaggerated proinflammatory, procoagulant state of PE. However, protein composition of STBM in normal pregnancy and PE remains unknown. We therefore sought to determine the protein components of STBM and whether STBM protein expressions differ in preeclamptic and normal pregnancies.

Patients with PE (n = 3) and normal pregnant controls (n = 6) were recruited. STBM were prepared from placental explant culture supernatant. STBM proteins were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expressions levels were quantified using spectral counts and validated by immunohistochemistry.

Results

Over 400 proteins were identified in the STBM samples. Among these, 25 proteins were found to be differentially expressed in preeclampsia compared to healthy pregnant controls, including integrins, annexins and histones.

Conclusion

STBM proteins include those that are implicated in immune response, coagulation, oxidative stress, apoptosis as well as lipid metabolism pathways. Differential protein expressions of STBM suggest their pathophysiological relevance in PE.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-11-40) contains supplementary material, which is available to authorized users.

Maternal hyperlipidemia and the risk of preeclampsia: a meta-analysis

Published reports examining lipid levels during pregnancy and preeclampsia have been inconsistent. The objective of this meta-analysis was to test the association between preeclampsia and maternal total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), non-HDL-C, and triglyceride levels measured during pregnancy. We conducted a systematic search for studies published between the index date until July 2013 reporting maternal lipid levels in women with preeclampsia and normotensive pregnant women. Seventy-four studies met all eligibility criteria and were included in the meta-analysis. Weighted mean differences in lipid levels were calculated using a random-effects model. Statistical heterogeneity was investigated using the I(2) statistic. Meta-regression was used to identify sources of heterogeneity. Preeclampsia was associated with elevated total cholesterol, non-HDL-C, and triglyceride levels, regardless of gestational age at the time of blood sampling, and with lower levels of HDL-C in the third trimester. A marginal association was found with LDL-C levels. Statistical heterogeneity was detected in all analyses. Meta-regression analyses suggested that differences in body mass index (weight (kg)/height (m)(2)) across studies may be partially responsible for the heterogeneity in the triglyceride and LDL-C analyses. This systematic review and meta-analysis demonstrates that women who develop preeclampsia have elevated levels of total cholesterol, non-HDL-C, and triglycerides during all trimesters of pregnancy, as well as lower levels of HDL-C during the third trimester.

Interaction of body mass index and hemoglobin concentration on blood pressure among pregnant women in Guangxi, China

Background

Body mass index (BMI) and hemoglobin (Hb) are positively associated with hypertensive disorders among pregnant women. The aim of this study was to estimate a potential interaction between high BMI and high Hb concentrations on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in pregnancy.

Methods

We recruited 4497 single-birth women aged 18–43 years who received routine antenatal care at three hospitals of Guigang, Guangxi, China, from December 2007 to January 2011. Of 4497 participants, 3472 women were in the first trimester, with following up, 2986 women and 2261 women were left in the second and third trimester, respectively. Clinical data were derived from medical records of each woman. We used multivariable linear regression, by trimesters of pregnancy, to evaluate the associations of high BMI and high Hb concentrations with SBP and DBP according to cross-sectional design.

Results

In multivariable analyses, BMI was positively associated with SBP throughout all trimesters, but the corresponding association for Hb concentrations only in the first trimester, whereas both BMI and Hb concentrations were positively associated with DBP in the first and third trimesters. After full adjustment for confounding, the average differences in SBP and DBP comparing women with high BMI and high Hb to those with non-high BMI and non-high Hb were 2.9 mmHg (95% CI: 0.8 to 5.0 mmHg) and 3.9 mmHg (95% CI: 1.5 to 6.3 mmHg) in the first trimester, 2.6 mmHg (95% CI: 0.4 to 4.8 mmHg) and 1.5 mmHg (95% CI: -1.3 to 4.3 mmHg) in the second trimester, and 4.8 mmHg (95% CI: 2.3 to 7.4 mmHg) and 5.7 mmHg (95% CI: 3.2 to 8.3 mmHg) in the third trimester, respectively. With respect to the interaction, significant combined effects between high BMI and high Hb were confirmed on SBP (P = 0.02) and DBP (P = 0.004) in the third trimester, and the amount of interaction on SBP and DBP were 2.0 mmHg (95% CI: 0.1 to 3.9 mmHg) and 2.3 mmHg (95% CI: 0.4 to 4.3 mmHg), respectively.

Conclusion

Our findings suggest that high BMI and high Hb concentrations may have a synergistic effect on blood pressure in late stage of pregnancy.

In Preeclampsia, Maternal Third Trimester Subcutaneous Adipocyte Lipolysis Is More Resistant to Suppression by Insulin Than in Healthy Pregnancy

Obesity increases preeclampsia risk, and maternal dyslipidemia may result from exaggerated adipocyte lipolysis. We compared adipocyte function in preeclampsia with healthy pregnancy to establish whether there is increased lipolysis. Subcutaneous and visceral adipose tissue biopsies were collected at caesarean section from healthy (n=31) and preeclampsia (n=13) mothers. Lipolysis in response to isoproterenol (200 nmol/L) and insulin (10 nmol/L) was assessed. In healthy pregnancy, subcutaneous adipocytes had higher diameter than visceral adipocytes ( P <0.001). Subcutaneous and visceral adipocyte mean diameter in preeclampsia was similar to that in healthy pregnant controls, but cell distribution was shifted toward smaller cell diameter in preeclampsia. Total lipolysis rates under all conditions were lower in healthy visceral than subcutaneous adipocytes but did not differ after normalization for cell diameter. Visceral adipocyte insulin sensitivity was lower than subcutaneous in healthy pregnancy and inversely correlated with plasma triglyceride ( r =−0.50; P =0.004). Visceral adipose tissue had lower ADRB3, LPL , and leptin and higher insulin receptor messenger RNA expression than subcutaneous adipose tissue. There was no difference in subcutaneous adipocyte lipolysis rates between preeclampsia and healthy controls, but subcutaneous adipocytes had lower sensitivity to insulin in preeclampsia, independent of cell diameter ( P <0.05). In preeclampsia, visceral adipose tissue had higher LPL messenger RNA expression than subcutaneous. In conclusion, in healthy pregnancy, the larger total mass of subcutaneous adipose tissue may release more fatty acids into the circulation than visceral adipose tissue. Reduced insulin suppression of subcutaneous adipocyte lipolysis may increase the burden of plasma fatty acids that the mother has to process in preeclampsia.

Cytochrome P450-mediated metabolic alterations in preeclampsia evaluated by quantitative steroid signatures

Although preeclampsia has been suggested potential risk factors including placental and systemic inflammation, oxidative stress, and abnormal steroid metabolism during pregnancy, the pathogenesis of preeclampsia has not fully been elucidated, particularly in steroid metabolism. The association between various cytochrome P450 (CYP)-mediated steroid metabolic markers and preeclampsia risk was therefore investigated. The serum levels of 54 CYP-mediated regioselective hydroxysteroids and their substrates were quantitatively evaluated from both pregnant women with preeclampsia (n=30; age, 30.8±4.5 years) and normotensive controls (n=30; age, 31.0±3.5 years), who were similar with respect to maternal age, gestational age, and body mass index. The levels of 6ß-, 7a-, and 11ß-hydroxymetabolites of androgens and corticoids were significantly increased in women with preeclampsia. In addition, the levels of oxysterols, including 7a-, 7ß-, 4ß-, 20a-, 24S-, and 27-hydroxycholesterol, were markedly higher, while the levels of 16a-OH-DHEA, 16a-OH-androstenedione, and cholesterol were significantly decreased in patients. The 6ß-hydroxylation of androgens and corticoids by CYP3A4 (P<0.01), the activation of 20,22-desmolase (a cholesterol side-chain cleavage enzyme) by CYP11A1 (P<0.00001), and the multi-hydroxylation of cholesterol at C-4ß, C-7a, C-7ß, C-24S, C-27, and C-20a (P<0.0001) by catalytic or enzymatic reaction (e.g. CYP3A4, CYP7A1, CYP27A1, and CYP46A1) were differed between preeclamptic women and control subjects. In particular, an increased oxysterols (induction>2.0-fold) were positively correlated with the conditions of preeclampsia. Our metabolic profiling suggests the CYP-mediated alterations in steroid metabolism and hydroxylation in pregnancy-induced hypertension. These multiple markers could serve as background information for improved clinical diagnosis and management during pregnancy. This article is part of a Special Issue entitled "Pregnancy and Steroids".

Cardiovascular risk, lipids and pregnancy: preeclampsia and the risk of later life cardiovascular disease

It has been widely thought that the effects of hypertension in pregnancy reversed after delivery and hypertension values returned to their pre-pregnancy level as it was seen as a disease of short duration in otherwise healthy young women. However, recent studies have demonstrated that the principal underlying abnormality, endothelial dysfunction, remains in women who had preeclampsia and that it is this damage that increases the risk of developing cardiovascular disease (CVD) in later life. The contributions of hypertension and dyslipidaemia before and during the pregnancy are also important and contribute to future risk. Serum lipids are complex and change dramatically in pregnancy. In general there is an increase in most plasma lipid components, notably triglycerides, total cholesterol and the major particles of HDL and LDL. Aberrations or exaggerations in this shift (i.e. decrease HDL and a greater increase in LDL) are associated with poor outcomes of pregnancy such as preeclampsia. Long term cardiovascular disease is influenced by preeclampsia and in part potentially by the lipid changes which escalate late in disease. Whether we can influence the risk of preeclampsia by controlling cardiovascular risk factors preceding or during preeclampsia, or cardiovascular disease after preeclampsia is yet to be determined. Ultimately, strategies to control lipid concentrations will only be viable when we understand the safety to the mother at the time of the pregnancy, and to the foetus both immediately and in the very long term. Strategies to control blood pressure are well established in the non-pregnant population, and previous preeclampsia and gestational hypertension should be considered in any cardiovascular risk profile. Whether control of blood pressure in the pregnancy per se is of any longer term benefit is also yet to be determined.

Plasma lipoproteins and preeclampsia in women with type 1 diabetes: a prospective study

CONTEXT

In nondiabetic pregnancy, cross-sectional studies have shown associations between maternal dyslipidemia and preeclampsia (PE). In type 1 diabetes mellitus (T1DM), the prevalence of PE is increased 4-fold, but prospective associations with plasma lipoproteins are unknown.

OBJECTIVES

The aim of this study was to define lipoprotein-related markers and potential mechanisms for PE in T1DM.

DESIGN AND SETTINGS

We conducted a multicenter prospective study in T1DM pregnancy.

PATIENTS

We studied 118 T1DM women (26 developed PE, 92 remained normotensive). Subjects were studied at three visits before PE onset [12.2 ± 1.9, 21.6 ± 1.5, and 31.5 ± 1.7 wk gestation (means ± SD)] and at term (37.6 ± 2.0 wk). Nondiabetic normotensive pregnant women (n = 21) were included for reference.

MAIN OUTCOME MEASURES

Conventional lipid profiles, lipoprotein subclasses [defined by size (nuclear magnetic resonance) and by apolipoprotein content], serum apolipoproteins (ApoAI, ApoB, and ApoCIII), and lipolysis (ApoCIII ratio) were measured in T1DM women with and without subsequent PE.

RESULTS

In women with vs. without subsequent PE, at the first and/or second study visits: low-density lipoprotein (LDL)-cholesterol, particle concentrations of total LDL and large (but not small) LDL, serum ApoB, and ApoB:ApoAI ratio were all increased (P < 0.05); peripheral lipoprotein lipolysis was decreased (P < 0.01). These early differences remained significant in covariate analysis (glycated hemoglobin, actual prandial status, gravidity, body mass index, and diabetes duration) but were not present at the third study visit. High-density lipoprotein and very low-density lipoprotein subclasses did not differ between groups before PE onset.

CONCLUSIONS

Early in pregnancy, increased cholesterol-rich lipoproteins and an index suggesting decreased peripheral lipolysis were associated with subsequent PE in T1DM women. Background maternal lipoprotein characteristics, perhaps masked by effects of late pregnancy, may influence PE risk.

Proteomic analysis of human serum for finding pathogenic factors and potential biomarkers in preeclampsia

OBJECTIVE(S)

To apply a novel proteomic method to discover potential pathogenic factors and biomarkers of preeclampsia.

STUDY DESIGN

Sera from five patients complicated with preeclampsia and five healthy pregnant controls were separately pooled. Each pool was treated with peptide ligand library beads (PLLBs) to remove high abundance proteins by affinity and thus enrich low abundance proteins. The proteins from the eluate were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expression levels were quantified using spectral counts and the extracted ion current.

RESULTS

1172 unique proteins in preeclampsia and 1149 in healthy controls were identified in the present study. 51 proteins were differentially expressed between preeclampsia and healthy pregnant women including chorionic somatommammptropin hormone (CSH) and fibulin-1. 31 proteins identified were up-regulated and 20 were down-regulated.

CONCLUSIONS

The results demonstrate that peptide ligand library combining with 1D gel-LC-MS/MS analysis is an efficient method to identify differentially expressed proteins in sera and two biological processes of complement and coagulation activations and lipid metabolism were involved in the pathogenesis of preeclampsia.

Steroid profiling in preeclamptic women: evidence for aromatase deficiency

OBJECTIVE

Experimental data have revealed the critical role played by 2-methoxy-estradiol, a metabolite of 17β-estradiol, in the pathophysiology of preeclampsia. We used gas chromatography/mass spectrometry to measure a whole panel of hormonal steroids in the plasma from women during the third trimester of their pregnancy.

STUDY DESIGN

The population study consists of 24 pregnant patients with different outcomes: normal, or complicated by isolated preeclampsia or by severe preeclampsia with Hemolysis Enzyme Liver Low Platelets (HELLP) syndrome.

RESULTS

17β-estradiol was reduced by 50% in isolated preeclampsia, and by 70% in severe preeclampsia with HELLP syndrome (normal: 8.54 ± 0.9 ng/mL; isolated preeclampsia: 4.65 ± 1.0 ng/mL; severe preeclampsia with HELLP syndrome: 2.64 ± 0.4 ng/mL), as is estrone. Downstream, 2-methoxy-estradiol was decreased only in severe preeclampsia with HELLP syndrome. The concentrations of estrone and 17β-estradiol precursors were comparable between groups, suggesting that placental aromatase is deficient in preeclampsia.

CONCLUSION

The gradual decrease of estrogen levels with increasing severity of preeclampsia suggests an impairment of placental steroidogenesis.

Maternal obesity markedly increases placental fatty acid transporter expression and fetal blood triglycerides at midgestation in the ewe

Obesity of women at conception is increasing, a condition associated with offspring obesity. We hypothesized that maternal obesity increases placental fatty acid transporter (FATP) expression, enhancing delivery of fatty acids to their fetuses. Sheep are a commonly utilized biomedical model for pregnancy studies. Nonpregnant ewes were randomly assigned to a control group [100% of National Research Council (NRC) recommendations] or obese group (OB, 150% of NRC) from 60 days before conception to 75 or 135 days of gestation (dG; term = 150 dG), when placental cotyledonary tissue was collected for analysis. Fetuses of OB ewes were markedly heavier (P < 0.05) on 75 dG than fetuses from control ewes, but this difference disappeared by 135 dG. Maternal obesity markedly increased (P < 0.05) cholesterol and triglyceride concentrations of both maternal and fetal blood. There is no difference in lipoprotein lipase mRNA expression between control and OB group at either gestational age. On 75 dG, the mRNA expression of FATP1 (P < 0.05), FATP4 (P = 0.08), and fatty acid translocase CD (cluster of differentiation) 36 (P < 0.05) proteins were more enhanced in cotyledonary tissue from OB than control ewes; consistently, protein expression of FATP1 and FATP4 was increased (P < 0.05). Similarly, on 135 dG, the mRNA levels of FATP1, FATP4, and CD36 were all higher (P < 0.05), but only FATP4 protein content was enhanced (P < 0.05) in OB cotyledonary tissue. Peroxisome proliferator-activated receptor (PPAR)-γ regulates the expression of FATPs. Both the mRNA expression and protein content of PPARγ were increased in OB cotyledonary in the midgestation. In conclusion, maternal obesity enhances the mRNA expression and protein content of FATPs in cotyledonary in the midgestation, which is associated with higher PPARγ content in cotyledonary.

Maternal obesity up-regulates inflammatory signaling pathways and enhances cytokine expression in the mid-gestation sheep placenta

Obesity in pregnant women is a growing public health concern. The placenta is a source of cytokines which can induce maternal gestational insulin resistance and alter nutrient transport to the fetus. Obesity induces placental inflammation at term, but the impact of obesity on placental inflammation earlier in pregnancy has not been defined. Using sheep as an experimental model, we hypothesized that maternal obesity (MO) would induce inflammation in the cotyledonary (COT) tissue of the placentome by mid-gestation. Nonpregnant ewes were randomly assigned to a control (C, 100% of NRC recommendations) or obese (OB, 150% of NRC) group from 60 days before conception to 75 day of gestation (dG), when ewes were necropsied and placental COT tissue collected for analyses. Free fatty acids content, triglyceride and cholesterol content were higher (P < 0.05) in the fetal plasma of OB compared to C ewes on day 75. MO increased mRNA levels of toll-like receptor (TLR) 2 (P < 0.05) and TLR4 (P = 0.06), macrophage markers cluster of differentiation (CD)11b (P = 0.06), CD14 and CD68 (P < 0.05), and proinflammatory cytokines tumor necrosis factor (TNF)alpha (P < 0.01), interleukin (IL)-6 (P < 0.05), IL-8(P < 0.01) and IL-18 (P = 0.06), in COT tissue. Inflammatory c-Jun N-terminal kinase (JNK)/c-Jun and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) signaling pathways were up-regulated (P < 0.05) in COT of OB ewes. In conclusion, MO enhanced the placental inflammatory response in OB ewes at mid-gestation, possibly as a result of increased TLR4 and free fatty acids.

Fetal sex determines the impact of maternal PROGINS progesterone receptor polymorphism on maternal physiology during pregnancy

BACKGROUND

Recent evidence from very rare human diseases suggests that variation in the fetal genome can modify maternal physiology during pregnancy. Here, we tested the hypothesis that fetal sex as a major genetic variant of the fetal genome may affect maternal physiology during pregnancy in genetically susceptible pregnant women.

METHODS

We analyzed the impact of fetal sex on maternal physiology during pregnancy in relationship with the maternal PROGINS progesterone receptor gene polymorphism. Two thousand and eighty-nine (2089) Caucasian women without preexisting diabetes and preexisting hypertension with singleton pregnancies delivering consecutively at the Charité obstetrics department participated in this study.

RESULTS

The maternal PROGINS progesterone receptor polymorphism on its own had no effect on blood pressure, new onset of proteinuria, and total glycated hemoglobin at delivery. However, by considering the offspring's sex, the AA variant of the PROGINS progesterone receptor polymorphism was associated with profound cardiovascular/metabolic effects; mothers carrying both A alleles (AA genotype) delivering a boy had significantly lower systolic blood pressure during the first trimester of pregnancy versus AA mothers delivering girls (107.9+/-10.2 vs. 116.6+/-15.1 mmHg, P = 0.044). Diastolic blood pressure was similarly lower during the first trimester of pregnant AA women delivering boys in comparison with AA women delivering girls (63.4+/-5.7 vs. 68.2+/-10.9 mmHg, P = 0.032). Total glycated hemoglobin at delivery was significantly (P = 0.002) higher in AA mothers delivering boys (6.6+/-0.7%) versus AA mothers delivering girls (5.9+/-0.6%).

CONCLUSION

Our study indicates that fetal sex may substantially affect maternal blood pressure as well as glycemic control during pregnancy in genetically susceptible mothers.

Free fatty acid profiles in preeclampsia

Preeclampsia has many characteristics similar to the metabolic syndrome. One of these is aberrant lipid metabolism. We studied free fatty acid (FFA) profiles at baseline and after oral glucose load in 21 preeclamptic and 11 normotensive pregnant women. Insulin sensitivity was measured by intravenous glucose tolerance test. We found that serum total FFA concentrations at baseline were 67% higher in preeclamptic than in normotensive pregnancies (P=0.0002). The difference between the two groups was largest in the concentrations of oleic (75%), linoleic (129%) and arachidonic (315%) acids. Oral intake of glucose suppressed total FFA in preeclamptic women by 40% (95% CI 32.1-46.1%, P<0.0001) but only 24% in control women (95% CI 0.01-42.0%, P=0.045). Insulin sensitivity, which in preeclamptic women was 37% lower (P=0.009), was unrelated to total or any individual FFA concentration. We concluded that preeclamptic women have higher circulating FFA concentrations, which despite insulin resistance are suppressed by oral glucose loading.

Placental ischemia and cardiovascular dysfunction in preeclampsia and beyond: making the connections

Hypertensive disorders of pregnancy continue to be a significant source of maternal and fetal morbidity and mortality, and recent evidence suggests that the incidence of preeclampsia (PE) is increasing. Recent epidemiological studies indicate that the effects of PE may persist long after pregnancy, in both the mother and the offspring, as increased incidence of cardiovascular disease. The last decade has produced new insights into the pathogenesis of PE. The initiating event in PE appears to be impaired placental perfusion and subsequent placental ischemia, which results in the elaboration of numerous factors. Factors such as soluble fms-like tyrosine kinase-1, soluble endoglin and the angiotensin II type-1 receptor autoantibodies contribute to maternal endothelial and cardiovascular dysfunction, marked by increased reactive oxygen species and decreased bioavailable VEGF, nitric oxide and prostacyclin. However, the importance of the various endothelial and humoral factors that mediate these changes during PE remain to be elucidated.

Pathophysiology of hypertension during preeclampsia: linking placental ischemia with endothelial dysfunction

Studies over the last decade have provided exciting new insights into potential mechanisms underlying the pathogenesis of preeclampsia. The initiating event in preeclampsia is generally regarded to be placental ischemia/hypoxia, which in turn results in the elaboration of a variety of factors from the placenta that generates profound effects on the cardiovascular system. This host of molecules includes factors such as soluble fms-like tyrosine kinase-1, the angiotensin II type 1 receptor autoantibody, and cytokines such as tumor necrosis factor-alpha, which generate widespread dysfunction of the maternal vascular endothelium. This dysfunction manifests as enhanced formation of factors such as endothelin, reactive oxygen species, and augmented vascular sensitivity to angiotensin II. Alternatively, the preeclampsia syndrome may also be evidenced as decreased formation of vasodilators such as nitric oxide and prostacyclin. Taken together, these alterations cause hypertension by impairing renal pressure natriuresis and increasing total peripheral resistance. Moreover, the quantitative importance of the various endothelial and humoral factors that mediate vasoconstriction and elevation of arterial pressure during preeclampsia remains to be elucidated. Thus identifying the connection between placental ischemia/hypoxia and maternal cardiovascular abnormalities in hopes of revealing potential therapeutic regimens remains an important area of investigation and will be the focus of this review.

Systematic review: Accuracy of body mass index in predicting pre-eclampsia: bivariate meta-analysis

OBJECTIVE

The objective of this study was to determine the accuracy of body mass index (BMI) (pre-pregnancy or at booking) in predicting pre-eclampsia and to explore its potential for clinical application.

DESIGN

Systematic review and bivariate meta-analysis.

SETTING

Medline, Embase, Cochrane Library, MEDION, manual searching of reference lists of review articles and eligible primary articles, and contact with experts.

POPULATION

Pregnant women at any level of risk in any healthcare setting.

METHODS

Reviewers independently selected studies and extracted data on study characteristics, quality, and accuracy. No language restrictions.

MAIN OUTCOME MEASURES

Pooled sensitivities and specificities (95% CI), a summary receiver operating characteristic curve, and corresponding likelihood ratios (LRs). The potential value of BMI was assessed by combining its predictive capacity for different prevalences of pre-eclampsia and the therapeutic effectiveness (relative risk 0.90) of aspirin.

RESULTS

A total of 36 studies, testing 1,699,073 pregnant women (60,584 women with pre-eclampsia), met the selection criteria. The median incidence of pre-eclampsia was 3.9% (interquartile range 1.4-6.8). The area under the curve was 0.64 with 93% of heterogeneity explained by threshold differences. Pooled estimates (95% CI) for all studies with a BMI > or = 25 were 47% (33-61) for sensitivity and 73% (64-83) for specificity; and 21% (12-31) and 92% (89-95) for a BMI > or = 35. Corresponding LRs (95% CI) were 1.7 (0.3-11.9) for BMI > or = 25 and 0.73 (0.22-2.45) for BMI < 25, and 2.7 (1.0-7.3) for BMI > or = 35 and 0.86 (0.68-1.07) for BMI < 35. The number needed to treat with aspirin to prevent one case of pre-eclampsia ranges from 714 (no testing, low-risk women) to 37 (BMI > or = 35, high-risk women).

CONCLUSIONS

BMI appears to be a fairly weak predictor for pre-eclampsia. Although BMI is virtually free of cost, noninvasive, and ubiquitously available, its usefulness as a stand-alone test for risk stratification must await formal cost-utility analysis. The findings of this review may serve as input for such analyses.

Obesity and pregnancy complications

Maternal obesity increases the risk of numerous complications of pregnancy, labor, and birth for both mother and neonate, including diabetes and hypertensive disorders. As more women enter pregnancy with a body mass index (BMI) indicative of overweight or obesity, providers of obstetric care should be aware of the implications of this increased BMI on perinatal outcomes as well as become familiar with management options.

Adiponectin in severe preeclampsia

AIMS

Adiponectin is an adipokine with insulin-sensitizing, anti-atherogenic, anti-inflammatory and angiogenic properties. The aims of this study were to determine whether maternal plasma adiponectin concentrations differ between patients with severe preeclampsia and those with normal pregnancies, and to explore the relationship between plasma adiponectin and the results of Doppler velocimetry of the uterine arteries.

METHODS

This case-control study included two groups: (1) patients with severe preeclampsia (n=50) and (2) patients with normal pregnancies (n=150). Pulsed-wave and color Doppler ultrasound examination of the uterine arteries were performed. Plasma adiponectin concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

RESULTS

(1) Patients with severe preeclampsia had a higher median plasma concentration of adiponectin than that of normal pregnant women. (2) The median plasma adiponectin concentration did not differ between women with severe preeclampsia who had a high impedance to blood flow in the uterine arteries and those with normal impedance to blood flow. (3) Among patients with normal pregnancies, plasma adiponectin concentrations were negatively correlated with BMI in the first trimester and at sampling.

CONCLUSIONS

Women with severe preeclampsia have a higher median plasma concentration of adiponectin than that of normal pregnant women. This may reflect a compensatory feedback mechanism to the metabolically-altered, anti-angiogenic and pro-atherogenic state of severe preeclampsia.

Pre-eclampsia: contribution of maternal constitutional factors and the consequences for cardiovascular health

1. Pre-eclampsia is a serious complication of pregnancy that is potentially life threatening for both the mother and baby. It encompasses a number of abnormalities that may be present in other clinical conditions. 2. A placenta is essential for the development of pre-eclampsia and can be important in the pathogenesis of pre-eclampsia. Normal pregnancy is associated with remodelling of the maternal spiral arteries, which deliver blood to the placental villous space. Remodelling involves invasion by placental cytotrophoblasts that cause the maternal spiral arteries to lose their smooth muscle and become capacitance vessels; this process, known as placentation, is complete by 20 weeks of pregnancy. Poor placentation is associated with small-for-gestational-age fetuses and some cases of pre-eclampsia. It is thought that poor placentation can result in a hypoxic placenta that releases 'toxic substances' into the maternal circulation, contributing to the maternal syndrome. A number of candidate 'toxic substances' have been proposed, but none is universally raised in pre-eclampsia. 3. Although the placenta is necessary for the development of pre-eclampsia, the extent to which placental abnormalities contribute to the condition varies. It is becoming apparent that maternal constitutional factors may also be important in this syndrome. Underlying hypertension, diabetes and obesity strongly predispose to pre-eclampsia. However, a continuum of risk may exist for blood pressure, bodyweight, glucose and lipids, which, in combination with each other and some degree of placental abnormalities, may lead to the development of pre-eclampsia. 4. The present review will focus on the maternal constitutional factors that define the metabolic syndrome and examine their contribution to pre-eclampsia and the long-term consequences for cardiovascular health.

n − 3 Fatty acid supplementation during pregnancy in women with allergic disease: effects on blood pressure, and maternal and fetal lipids

n−3 Fatty acids derived from fish oil reduce plasma triacylglycerols (triglycerides) and increase HDL-C (high-density lipoprotein cholesterol); however, the effect of n−3 fatty acid supplementation during pregnancy, a hyperlipidaemic state, remains unknown. We took the opportunity to investigate maternal lipid levels and blood pressure during and after pregnancy, and fetal lipid levels at birth, in a study that aimed primarily to examine the effect of fish oil supplementation during pregnancy on immune function in infants born to women with allergic disease. Eighty-three pregnant women who had allergic disease, but were otherwise healthy, completed the study. They were randomly allocated to receive fish oil or olive oil capsules, taken as 4 g/day, from 20 weeks of pregnancy until delivery. Compared with olive oil, fish oil supplementation did not alter triacylglycerols, total cholesterol, LDL-C (low-density lipoprotein cholesterol) or HDL-C during or after pregnancy. There was also no effect of fish oil on cord blood triacylglycerols, total cholesterol, LDL-C or HDL-C. Fish oil supplementation during pregnancy did not alter maternal blood pressure during or after pregnancy. The effects of fish oil on lipids and blood pressure in non-pregnant individuals appear to be lost when it is administered during pregnancy.

BMI: new aspects of a classical risk factor for hypertensive disorders in pregnancy

HDP (hypertensive diseases in pregnancy) are one of the leading causes of maternal and fetal mortality and morbidity. BMI (body mass index) is an established risk factor for pre-eclampsia, but its role in HELLP syndrome is unknown. We therefore investigated BMI as a risk factor in the development of HELLP syndrome. At the beginning of pregnancy, BMI was measured in 1067 women with a history of HDP and 1063 controls. Diagnoses of HDP were classified according to ISSHP (International Society for the Study of Hypertension in Pregnancy) and BMI according to WHO (World Health Organization) criteria. After verification of exclusion criteria and matching for confounders, 687 women with hypertensive diseases in pregnancy and 601 controls remained for statistical evaluation by χ2 test and multiple logistic regressions. As a continuous variable, the increase in BMI was associated with an increase in the development of gestational hypertension {OR (odds ratio), 1.1 [95% CI (confidence interval) 1.062–1.197]} and pre-eclampsia [OR, 1.1 (95% CI, 1.055–1.144)]}, but not for HELLP syndrome. According to WHO definitions, overweight women (BMI ≥25 and <30 kg/m2) had a 2-fold (95% CI, 1.365–2.983) risk and obese women (BMI ≥30 kg/m2) had a 3.2-fold (95% CI, 1.7–5.909) risk of developing pre-eclampsia when compared with women of normal weight (BMI ≥15.5 and <25 kg/m2). Being overweight or having obesity had no effect on the risk of HELLP syndrome. As an increased BMI is correlated with the risk of developing pre-eclampsia but not HELLP syndrome, both diseases have a different risk profile. This finding supports that underlying physiological mechanisms in pre-eclampsia vary from those in HELLP syndrome.

Brief overview of maternal triglycerides as a risk factor for pre-eclampsia

BACKGROUND

Features of the metabolic syndrome-maternal obesity, diabetes mellitus and chronic hypertension-are risk factors for pre-eclampsia.

OBJECTIVES

To determine the risk of pre-eclampsia in the presence of maternal hypertriglyceridemia, another major element of the metabolic syndrome.

SEARCH STRATEGY

Two investigators independently searched PubMed and Embase databases from 1980 to December 2004 for relevant studies. The terms preeclampsia, eclampsia, pregnancy-induced hypertension or toxemia were combined with dyslipidemia, hyperlipidemia, hypertriglyceridemia, lipids, cholesterol, triglycerides (TG) or lipoprotein.

SELECTION CRITERIA

We included case-control and cohort studies published in English that included at least 20 women with pre-eclampsia and that sampled serum or plasma TG at any time before, during or after pregnancy.

DATA COLLECTION AND ANALYSIS

Mean maternal TG concentrations were compared between cases and controls within each study. The odds ratio of pre-eclampsia was calculated by comparing the risk of pre-eclampsia among women in each higher TG concentration category with that in the lowest reference category.

MAIN RESULTS

A total of 19 case-control and 3 prospective cohort studies were included. In 14 studies, the mean TG concentration was significantly higher among pre-eclamptic cases than among unaffected controls; in seven other studies, there was a nonsignificant trend in the same direction. The risk of pre-eclampsia typically doubled with each increasing TG category. In the four studies that adjusted for potential confounders, such as maternal age, parity and body mass index, there was about a four-fold higher risk of pre-eclampsia in the highest relative to the lowest TG category.

AUTHOR'S CONCLUSIONS

There exists a consistent positive association between elevated maternal TG and the risk of pre-eclampsia. Given that maternal hypertriglyceridemia is a common feature of the metabolic syndrome, interventional studies are needed to determine whether pre-pregnancy weight reduction and dietary modification can lower the risk of pre-eclampsia.

The role of nitric oxide in the peripheral vasoconstriction caused by human placental lactogen in anaesthetized pigs

Regional intra-arterial infusion of human placental lactogen in anaesthetized pigs has been shown to cause coronary, renal and iliac vasoconstriction by antagonizing the vasodilatory effects of beta2-adrenergic receptors. Since nitric oxide is known to modulate or mediate beta2-adrenergic effects, the present study was planned in the same experimental model to determine the role of nitric oxide in the above vascular responses to human placental lactogen. In eight pigs anaesthetized with sodium pentobarbitone, changes in anterior descending coronary, left renal and left internal iliac blood flow caused by intra-arterial infusion of human placental lactogen at constant heart rate and arterial blood pressure were assessed using electromagnetic flowmeters. Intra-arterial infusion of the human placental lactogen caused decreases in coronary, renal and iliac blood flow which, respectively, averaged 16.7, 8.1 and 12.2% of the baseline values. The role of nitric oxide in this response was studied in the same pigs by repeating the experiments, after measured blood flows had returned to baseline values, following intra-arterial administration of N(omega)-nitro-L-arginine methyl ester (L-NAME). The subsequent intra-arterial infusion of human placental lactogen did not cause any significant changes in measured blood flows, even when performed after reversing the increase in arterial blood pressure and coronary, renal and iliac resistance caused by L-NAME with continuous intravenous infusion of papaverine. These results indicate that the coronary, renal and iliac vasoconstriction caused by human placental lactogen, known to involve antagonism of beta2-adrenergic vasodilatory effects, was mediated by inhibition of nitric oxide release.

Human Placental Lactogen Decreases Regional Blood Flow in Anesthetized Pigs

In 22 pigs anesthetized with sodium pentobarbitone, changes in blood flow caused by infusion of human placental lactogen into the left renal, external iliac, and anterior descending coronary arteries were assessed using electromagnetic flowmeters. In 17 pigs, infusion of human placental lactogen whilst keeping the heart rate and arterial pressure constant decreased coronary, renal and iliac flow. In 5 additional pigs, increasing the dose of human placental lactogen produced a dose-related decrease in regional blood flow. The mechanisms of the above response were studied in 15 of the 17 pigs by repeating the experiment of infusion. The human placental lactogen-induced decrease in regional blood flow was not affected by blockade of cholinergic receptors (5 pigs) or of alpha-adrenergic receptors (5 pigs), but it was abolished by blockade of beta2-adrenergic receptors (5 pigs). The present study showed that intra-arterial infusion of human placental lactogen primarily decreased coronary, renal and iliac blood flow. The mechanism of this response was shown to be due to the inhibition of a vasodilatory beta2-adrenergic receptor-mediated effect.

A lethal tetrad in diabetes: hyperglycemia, dyslipidemia, oxidative stress, and endothelial dysfunction

This paper addresses the consequences of diabetes and obesity, diseases that have become epidemic in our society, particularly in the past 20 years. Specifically, it summarizes current knowledge about some of the risk factors and mechanisms for the vascular complications of diabetes. These complications can be broadly divided into microvascular disease, such as diabetic retinopathy and diabetic nephropathy, and macrovascular disease, such as accelerated atherosclerosis, and they are the main cause for morbidity and premature mortality among diabetic patients. The roles of hyperglycemia, dyslipidemia and dyslipoproteinemia, oxidative stress, and endothelial dysfunction will be considered. Finally, the "treatment gap" will be addressed. This gap refers to our failure to achieve currently accepted goals to reduce established risk factors for complications in the clinical management of diabetic patients.

Preeclampsia

Preeclampsia is a pregnancy complication with serious consequences for mother and infant. The disorder is diagnosed by gestational hypertension and proteinuria but is far more than pregnancy induced hypertension. Preeclampsia is proposed to occur in 2 stages. Stage 1 reduced placental perfusion is postulated as the root cause and to lead to the maternal syndrome, Stage 2. Why perfusion is reduced, how this translates to a maternal disease in some but not all women and what is the linkage of the 2 stages are topics of intense study. In the last decade such studies have provided valuable insights into pathophysiology that now guide ongoing clinical trials.

Factors predisposing to pre-eclampsia in women with gestational diabetes

BACKGROUND

Lipid abnormalities occur before the onset of pre-eclampsia but their role in its pathogenesis is unclear. We tested the hypothesis that lipid abnormalities precede and contribute to the development of pre-eclampsia using women with gestational diabetes (GDM) as a focus population.

METHODS

One hundred and eighty-four women with a diagnosis of GDM were studied. Anthropometry, blood pressure, fasting lipids, glucose homeostasis, markers of inflammation and endothelial damage were measured and family history of disease was assessed to determine those measures at diagnosis of GDM that best predicted the development of pre-eclampsia.

RESULTS

Twelve percent of women with GDM developed pre-eclampsia. At diagnosis of GDM, total cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides were not different in women who subsequently developed pre-eclampsia (GDM-PE). GDM-PE had elevated body mass index, blood pressure, fasting glucose, insulin, uric acid, and C-reactive protein (CRP), which have all been linked with the 'metabolic syndrome'. They had a greater degree of microalbuminuria and more frequently reported a family history of hypertension and maternal gestational diabetes. In logistic regression, the significant independent predictors for developing pre-eclampsia were fasting glucose, CRP, a family history of hypertension and the proband's mother having gestational diabetes.

CONCLUSION

The results suggest that, in GDM, increased severity of insulin resistance and related features of the 'metabolic syndrome', rather than lipid abnormalities, are precursors to the development of pre-eclampsia and hence are likely to be implicated in the pathophysiology of this disorder. Moreover, these women are likely to be at particularly high risk of long-term cardiovascular disease and Type 2 diabetes.

Obesity and pregnancy

BACKGROUND

As obesity is an increasing problem among fertile women, it is crucial that specialists involved in the treatment of these women be aware of the risks of complications and know how to deal with them. Complications associated with obesity in pregnancy are gestational diabetes mellitus, hypertensive disorders, and thromboembolic complications. Complications associated with obesity in labor are augmentation, early amniotomy, cephalopelvic disproportion, cesarean section, and perioperative morbidity. Complications associated with obesity in children are macrosomia, shoulder dystocia, small for gestational age, late fetal death, and congenital malformations, especially neural tube defects.

OBJECTIVE

The aim was to review the potential complications associated with obesity and pregnancy.

RESULTS

Obesity is associated with a higher risk of all reviewed complications except small for gestational age.

Maternal birth weight in relation to plasma lipid concentrations in early pregnancy

OBJECTIVE

The purpose of this study was to determine the extent to which, if at all, maternal weight at birth is related to dyslipidemia during early pregnancy, which is a risk factor for preeclampsia.

STUDY DESIGN

This hospital-based prospective cohort study included 1000 women who initiated prenatal care before 16 weeks of gestation. Participants provided information about their birth weight and other sociodemographic and reproductive covariates. Plasma triglyceride, high-density lipoprotein cholesterol, and total cholesterol concentrations were measured at approximately 13 weeks of gestation. beta coefficients and standard errors were estimated by multiple linear regression; odds ratios and 95% confidence intervals were estimated by logistic regression.

RESULTS

Maternal birth weight was correlated negatively with triglycerides (r =-0.12; P =.001) and was correlated positively with high-density lipoprotein cholesterol (r =0.08; p =.02) but not statistically significantly related with total cholesterol (r =-0.004; P=.91). After adjusting for potential confounders, women who weighed <2500 g at birth had higher triglyceride and total cholesterol concentrations (beta=23.4 mg/dL [P<.001]; beta =2.6 mg/dL [P =.585], respectively) and lower high-density lipoprotein cholesterol concentrations (beta =-3.2 mg/dL; P=.105), when compared with women who weighed 3000 to 3499 g at birth. Women who were born small (<2500 g) and became overweight (body mass index, >or=25 kg/m(2)) in adulthood had less favorable lipid profiles than their counterparts who weighed >or=2500 g at birth and remained lean (body mass index, <25 kg/m(2)).

CONCLUSION

Our findings suggest that factors that are related to growth in utero may help to predict the subsequent risk of altered lipid metabolism during pregnancy, which may, in turn, be causally related to the occurrence of preeclampsia.

Study of serum levels of superoxide dismutase in preeclampsia and eclampsia: role of the test as a predictive tool

AIM

To report serum levels of superoxide dismutase in women with preeclampsia and eclampsia. To document the use of the value as a predictive tool for deciding the time of onset of subsequent convulsions with fulminating eclampsia and use of the value as a marker for obstetric intervention in clinical severe preeclampsia and eclampsia.

METHODS

Superoxide dismutase concentration was measured in a consecutive study in sera of women admitted in obstetric ward for preeclampsia and eclampsia, and compared with sera of normotensive, healthy pregnant women in third trimester. Three mL venous blood was subjected to superoxide dismutase estimation by pyrogallol autoxidation method.

RESULTS

We found statistically significant difference (P < 0.05) in mean superoxide dismutase levels of normotensive pregnant women; and preeclamptic and eclamptic subjects, no statistically significant difference was found in between value of enzyme in preeclampsia and eclampsia (P > 0.05). Superoxide dismutase levels in two pregnancy outcomes; live births and still births, shows significant difference (P < 0.05), being 1.03 U/mL and 0.52 U/mL, respectively. The comparison of values before delivery and after delivery showed highly statistically significant difference (P < 0.001) in both groups separately. The cut-off value of serum superoxide dismutase 0.52 U/mL has sensitivity 68.5%, specificity 59.5% and negative predictive value of 78.6%, for predicting the fetal death as outcome of pregnancy with severe grade of disease.

CONCLUSION

We found low levels of serum superoxide dismutase, less than 0.52 U/mL, being the predecessor of fulminating eclampsia. Our results support this predictive value of serum superoxide dismutase level as important in deciding the time of intervention as termination of pregnancy.

Blood pressure patterns through consecutive pregnancies are influenced by body mass index

OBJECTIVE

The purpose of this study was to analyze the impact of parity and baseline body mass index on blood pressure levels in pregnancy.

STUDY DESIGN

We studied a longitudinal historic cohort of 166 healthy pregnant women who gave birth in 2000 to a third child at the University Hospital of Lund; blood pressure measurements were obtained at each antenatal visit during the three consecutive pregnancies.

RESULTS

The mean systolic and diastolic blood pressure levels were consistently higher during the first pregnancy at comparable weeks of gestation, significantly so during the third trimester. The body mass index correlated with diastolic blood pressure levels only in the first pregnancy, and the impact of parity on third trimester blood pressure levels was greatest in the women with a high body mass index. Age, smoking, change of paternity, or a short time interval between pregnancies did not influence blood pressure levels.

CONCLUSION

The interrelationship among blood pressure levels, parity, and body mass index in normal pregnancy resembles the situation in hypertensive pregnancies, which implies common adaptive mechanisms.

Elevated tissue plasminogen activator as a potential marker of endothelial dysfunction in pre-eclampsia: correlation with proteinuria

OBJECTIVE

To clarify the role played by endothelial cell production of fibrinolytic factors in normal pregnancy and pre-eclampsia.

DESIGN

A longitudinal study performed during normal pregnancy and a cross sectional study performed in healthy and pre-eclamptic pregnant women in the third trimester of pregnancy.

SETTING

Department of Obstetrics and Gynaecology, University Hospital of S. João, Porto, Portugal.

POPULATION

Fourteen normal pregnant women followed through the three trimesters of gestation. Two groups of women (normal, n = 56; pre-eclamptic, n = 37) evaluated at the third trimester of gestation.

METHODS

Measurement of platelet number, plasma levels of fibrinogen, tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor-1 (PAI-1) activity, and fibrin fragment D-dimer.

MAIN OUTCOME MEASURES

Pre-eclampsia, proteinuria.

RESULTS

All the substances, except platelet count, increased significantly throughout normal pregnancy. Comparison of the values in the third trimesters of normal and pre-eclamptic pregnancies showed similar values for the fibrinogen and platelet counts, and higher values of t-PA (almost twice normal median value; P < 0.0001), PAI-1 and D-dimer in the pre-eclamptic women. t-PA correlated positively and significantly with the degree of proteinuria in pre-eclamptic women (r = 0.575, P = 0.0002).

CONCLUSION

These findings suggest that elevated t-PA antigen may reflect endothelial disturbance in preeclampsia, and may be a potential biomarker of risk.

Elevated levels of S-nitrosoalbumin in preeclampsia plasma

The availability of nitric oxide (NO), which is required for the normal regulation of vascular tone, may be decreased in preeclampsia, thus contributing to the vascular pathogenesis of this pregnancy disorder. Because ascorbate is essential for the decomposition of S-nitrothiols and the release of NO, we speculated that the ascorbate deficiency typical of preeclampsia plasma might result in decreased rates of decomposition of S-nitrosothiols. We tested the hypothesis that total S-nitrosothiol and S-nitrosoalbumin concentrations are increased in preeclampsia plasma, reflecting a decreased release of NO from these major reservoirs of NO. Gestationally matched plasma samples were obtained (before labor or intravenous MgSO(4)) from 21 women with preeclampsia and 21 women with normal pregnancy, and plasma samples were also obtained from 12 nonpregnant women of similar age and body mass index during the follicular phase of the menstrual cycle. All were nonsmokers. The assay included ultraviolet-induced decomposition of S-nitrosothiols to liberate NO captured by a florigenic reagent, 4,5-diaminofluoresceine, to produce diaminofluoresceine-Triazole. Preeclampsia plasma contained significantly higher concentrations of total S-nitrosothiols (11.1+/-2.9 nmol/mL) than normal pregnancy samples (9.4+/-1.5 nmol/mL). Even greater differences were found between preeclampsia plasma and plasma samples from normal pregnancies and nonpregnant women (294+/-110, 186+/-25, and 151+/-25 pmol/mg protein, respectively) when S-nitrosothiol content was expressed per milligram protein. The albumin fraction contained 49.4% of total plasma S-nitrosothiols in the control samples and 53.7% and 56.8% of plasma S-nitrosothiols in normal pregnancy and preeclampsia, respectively. The level of S-nitrosoalbumin was significantly higher in preeclampsia than in normal pregnancy or nonpregnancy plasma (6.3+/-1.4, 5.1+/-0.7, and 4.2+/-1.0 nmol/mL, respectively). The increased concentration of S-nitrosoalbumin in preeclampsia almost completely accounted for the increased levels of S-nitrosothiols in total plasma. Due to combined increases in nitrosothiols and decreases in protein, the preeclampsia plasma concentration of S-nitrosoalbumin was greatly increased on a per milligram of protein basis (271% and 186% compared with normal nonpregnancy and normal pregnancy plasma, respectively). We conclude that S-nitrosoalbumin and total S-nitrosothiol concentrations are significantly increased in preeclampsia plasma and may reflect insufficient release of NO groups in this condition.

Increased circulating lipid peroxides in severe preeclampsia activate NF-kappaB and upregulate ICAM-1 in vascular endothelial cells

Preeclampsia is a systemic disease of pregnancy characterized by maternal hypertension, proteinuria, and edema. These clinical pathological findings may be attributed to abnormalities in vascular endothelial activation secondary to increased oxidative stress. To test the hypothesis that increased circulating lipid peroxides in preeclamptic women activate vascular endothelial cells, we determined NF-kappaB transcriptional activity and ICAM-1 expression in human umbilical vein endothelial cells (HUVEC) cultured with plasma from women with severe preeclampsia (preeclamptic plasma, N = 12) or plasma from normal pregnancies (normal plasma, N = 12). Preeclamptic women had increased circulating lipid peroxides compared with normal pregnant women, as demonstrated by a 4.5-fold higher concentration of plasma malondialdehyde (PkB luciferase reporter construct transfected into HUVEC, preeclamptic plasma was found to up-regulate HUVEC NF-kappaB activity by 2.5-fold when compared with normal plasma (PkB activation in response to preeclamptic-plasma by 77% (PkB activation and ICAM-1 expression on HUVEC, which can be inhibited by vitamin E and N-acetyl-cysteine.

The effect of smoking on pre-eclampsia in twin pregnancy

OBJECTIVE

To assess the effect of smoking on the incidence of pre-eclampsia and on perinatal outcome in twin pregnancy.

DESIGN

Retrospective study using Aberdeen Maternity and Neonatal Databank.

SETTING

Grampian, Orkney and Shetland.

POPULATION

All 1,575 twin pregnancies delivered in the years 1969-1971 and 1976-1997 (when smoking data were available).

METHODS

In all twin pregnancies the effects of smoking on pre-eclampsia were analysed by parity and gestation at delivery. The effect of smoking upon late miscarriage and perinatal outcome was analysed without subdivision.

MAIN OUTCOME MEASURES

Pre-eclampsia and perinatal outcome.

RESULTS

Primiparae had significantly higher rates of pre-eclampsia than multiparae and were delivered significantly earlier. The incidence of pre-eclampsia in smokers was significantly lower only in multiparae. Length of gestation was significantly shorter in multiparous smokers. The effect of smoking on pre-eclampsia appeared to be direct in multiparae but possibly indirect in primiparae (by causing earlier delivery). Smokers had a higher late miscarriage rate than nonsmokers.

CONCLUSIONS

In twin pregnancy the apparent protective effect of smoking against pre-eclampsia is significant only in multiparae, suggesting that in primiparae the smoking effect is overwhelmed by the other reasons for the development of pre-eclampsia. Smoking in twin pregnancy is not recommended due to the worse fetal outcome rates.

Risk factors for pre-eclampsia in a large cohort of Latin American and Caribbean women

OBJECTIVE

To study risk factors for pre-eclampsia in a large cohort of Latin American and Caribbean women.

DESIGN

Retrospective cross-sectional study from the Perinatal Information System, the database of the Latin American Center for Perinatology and Human Development, Montevideo, Uruguay.

SETTING

Latin America and the Caribbean, 1985-1997. Population 878,680 pregnancies at 700 hospitals; of these 42,530 were complicated by pre-eclampsia and 1,872 by eclampsia.

MAIN OUTCOME MEASURES

Crude and adjusted relative risks (RR) of risk factors for pre-eclampsia. Adjusted relative risks were obtained after adjustment for potential confounding factors through multiple logistic regression models based on the method of generalised estimating equations.

RESULTS

The following risk factors were significantly associated with increased risk of pre-eclampsia: nulliparity (RR 2 x 38; 95% CI 2 x 28-2 x 49); multiple pregnancy (RR 2 x 10; 95% CI 1 x 90-2 x 32); history of chronic hypertension (RR 1 x 99; 95% CI 1 x 78-2 x 22); gestational diabetes mellitus (RR 1 x 93; 95% CI 1 x 66-2 x 25); maternal age > or = 35 years (RR 1 x 67; 95% CI 1 x 58-1 x 77); fetal malformation (RR 1 x 26; 95% CI 1 x 16-1 x 37); and mother not living with infant's father (RR 1 x 21; 95% CI 1 x 15-1 x 26). Pre-eclampsia risk increased according to pre-pregnancy body mass index (BMI). In comparison with women with a normal pre-pregnancy BMI (19 x 8 to 26 x 0), the RR estimates were 1 x 57 (95% CI 1 x 49-1 x 64) and 2 x 81 95% CI 2 x 69-2 x 94), respectively, for overweight women (pre-pregnancy BMI = 26 x 1 to 29 x 0) and obese women (pre-pregnancy BMI > 29 x 0). Cigarette smoking during pregnancy and a pre-pregnancy BMI < 19 x 8 were significant protective factors against the development of pre-eclampsia. The pattern of risk factors among nulliparous and multiparous women was quite similar.

CONCLUSIONS

Risk factors for pre-eclampsia observed among Latin American and Caribbean women are similar to those found among North American and European women.

Does a predisposition to the metabolic syndrome sensitize women to develop pre-eclampsia?

OBJECTIVE

This study aimed to identify those factors in the non-pregnant state that distinguished women who developed pre-eclampsia from those who had normotensive pregnancies.

DESIGN AND SETTING

This was a retrospective analysis of anthropometry, blood pressure, biochemical and haematological variables in 62 women with pre-eclampsia and 84 normotensive pregnant women who took part in studies of the pathophysiology of pre-eclampsia. Pregnant volunteers were seen, after admission to hospital or in the outpatient clinic, and followed-up at 6 weeks and 6 months post-partum in the outpatient clinic or their home. Participants Proteinuric pre-eclampsia was defined as blood pressure > or = 140/90 mmHg with proteinuria of at least 300 mg/24 h after 20 weeks gestation, in women with no history of hypertension and whose blood pressure returned to normal levels by 6 months post-partum. Normotensive pregnancy was defined as blood pressure < 130/90 mmHg without proteinuria.

MAIN OUTCOME MEASURES

The primary outcome measures were blood pressure, body mass index (BMI), triglycerides, total cholesterol, low density lipoprotein (LDL) and high density lipoprotein cholesterol and markers of severity of pre-eclampsia.

RESULTS

Regardless of parity, women with pre-eclampsia had elevated BMI before, during and after pregnancy compared with women who had normotensive pregnancies. Triglycerides were significantly elevated in women who had pre-eclampsia both before and after delivery, while total and LDL cholesterol were elevated significantly at both visits after delivery. Systolic and diastolic blood pressure, which by definition were elevated antepartum in women with pre-eclampsia, remained higher at post-partum visits compared with women who had normotensive pregnancies. Women with pre-eclampsia reported a greatly increased frequency of both maternal hypertension and pre-eclampsia. Markers of severity of pre-eclampsia, which normalized by 6 months postpartum, included plasma creatinine, uric acid, albumin, endothelin 1 and urinary protein, 2,3, dinor-6-keto-PGF1alpha, blood platelet and neutrophil counts.

CONCLUSION

The relative elevation of blood pressure, BMI and lipids in the non-pregnant state are features of the metabolic syndrome and may be important sensitizing factors contributing to the pathogenesis of pre-eclampsia. A familial predisposition to pre-eclampsia may operate partly through these mechanisms.

Serum insulin and lipid profile in normal pregnant and pregnancy-induced hypertensive women from North India

High serum insulin and lipoproteins have been reported in pregnancy-induced hypertension. Little is known about the insulin and lipoprotein profile in Indian women. To address this question we compared serum insulin and lipoproteins of women with pregnancy induced hypertension (PIH) and normotensive pregnant women. The serum insulin, triglycerides, total cholesterol and HDL cholesterol of 104 women with PIH were compared with 99 control women. Hypertensive women had significantly higher insulin (53.94 +/- 29.58 versus 37.69 +/- 17.39 pmol/L, p=0.0004) and triglyceride (3.27 +/- 1.2 versus 2.66 +/- 0.6, p=0.0001). There was no significant difference in total cholesterol and HDL cholesterol levels. Insulin levels had a positive correlation with systolic blood pressure (r=0.64) and diastolic blood pressure (r=0.55) in women with PIH. These differences persisted even after adjusting for possible confounding variables such as age, body mass index and the period of gestation. We conclude that elevated serum insulin values or insulin resistance may contribute to the pathogenesis of PIH in Indian women.