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(Hypertension. 2009;53:733.)
© 2009 American Heart Association, Inc.
Original Articles |
From the Departamentos de Nefrología (G.V.), Enfermedades Cardiovasculares (E.M., S.M., A.M.), and Salud Pública (O.P.), Escuela Medicina Pontificia Universidad Católica (F.Q., A.v.S.), Sección Cardiología, Hospital Sótero del Río (E.M.), Santiago, Chile.
Correspondence to Gloria Valdés, Departamento de Nefrología y Centro Investigaciones Médicas, Escuela Medicina Pontificia Universidad Católica, Marcoleta 391, PO Box 114-D, Santiago, Chile. E-mail gvaldes{at}med.puc.cl
| Abstract |
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1 HP, according to a questionnaire including reproductive history and cardiovascular risks. Body mass index, smoking, and frequency of diabetes were similar in both groups. Chronic hypertension (93% versus 78%; P=0.007), hyperlipidemia (82% versus 69%; P=0.049), and premature familial cardiovascular disease (42% versus 20%; P=0.001) prevailed in HPs. Participants with HPs were younger (58.9±8.3 versus 61.9±9.6 years; P=0.025) than participants with normotensive pregnancies. Although 49% of all participants had hemodynamically significant coronary artery disease (
70% stenosis), no differences were observed between groups in the number of stenotic arteries; however, their number increased by 28% and 22% over a 10-year period in HPs and normotensive pregnancies, respectively (P=0.034). Multivariate analysis showed that HPs had a nonsignificant risk of having coronary artery disease (odds ratio: 1.21; 95% CI: 0.64 to 2.28), and being a current smoker (odds ratio: 4.13; 95% CI: 1.85 to 9.25), a diabetic (odds ratio: 2.29; 95% CI: 1.85 to 9.25), or having a family history of premature cardiovascular disease (odds ratio: 2.34; 95% CI: 1.17 to 2.39) significantly increased the risk of coronary artery disease. This study demonstrates that women with HPs have earlier coronary disease, probably related to intermediate cardiovascular risks that have a gestational expression.
Key Words: hypertension in pregnancy preeclampsia coronary artery disease cardiovascular risks coronary angiography
| Introduction |
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We decided to take an intermediate stance, by testing whether those subjects who had hypertensive pregnancies (HPs) developed earlier or more extensive coronary lesions than controls who had normotensive pregnancies (NPs). For this purpose, we evaluated the remote obstetric histories in women who underwent coronary angiography, the gold standard for defining coronary disease.
| Methods |
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Body mass index was calculated for all of the participants. A personal history of hypertension, diabetes mellitus, and hyperlipidemia was defined by previous medical diagnosis or by current specific treatment. According to tobacco use, subjects were defined as nonsmokers, former smokers (ie, those who had stopped smoking for a year or more), and current smokers (ie, those who smoked any tobacco in the year before angiography).14 Premature familial CV disease was defined by myocardial infarction, coronary bypass, or stroke in first-degree relatives, occurring before 60 and 65 years of age in men and women, respectively.
HPs were defined by high blood pressure during any time during pregnancy, with no distinction made between the different types of hypertension in pregnancy. Low birth weight was defined as
2500 g and preterm births as those occurring at <36 weeks (ie,
8 months) in singleton pregnancies; recurrent abortions as
2 consecutive miscarriages; and impeccable gestational history by uncomplicated gestations in women who carried all pregnancies to term. The reports of these complications were obtained by recall, as the obstetric records could not be accessed.
Selective coronary angiograms, performed using the Judkins technique, were assessed by observers blinded to the obstetric history. Hemodynamically significant coronary stenosis was defined by a
70% narrowing of arterial lumen. Recent myocardial infarctions were diagnosed by regional alteration of left ventricular contractility and, when remote, by the presence of
2 of the following: electrocardiographic and enzymatic abnormalities at the time of the event, and alterations in left ventricular contractility.
Of the 486 women who underwent angiography during the 2-year study period, 9 died during the acute event; of the 477 remaining women, 268 (56.2%) could be contacted. The study group was composed of 217 women, aged 61.2±9.2 (SD) years, who underwent coronary angiography 36.8±9.9 and 28.8±10.5 years after the first and last pregnancies, respectively. These data describe the group after 51 women were excluded (27 women who had not received qualified professional attention in
1 pregnancy, 11 nulliparas, 9 women who declined or were unable to participate in the interview, and 4 women who provided discordant data). For the women who were deceased, not contacted, or excluded (n=269), data on CV risks and severity of coronary disease were obtained from the admission charts at the time of angiography.
Data Analysis
Results are expressed as means±SDs. Multiple-birth pregnancies were excluded from the analysis of pregnancy complications. The numeric analysis was performed using SPSS software. Normality was evaluated by the Shapiro-Wilks test. An unpaired t test was used for variables with a normal distribution, whereas the nonparametric Mann-Whitney test was used for variables with a nonnormal distribution. In addition, univariate and multivariate analysis, logistic regression, and Poisson regression were performed. Statistical significance was considered for P values
0.05.
The reproducibility of maternal recall regarding several of the parameters included in the study was tested by repeated interviews in a subgroup of 15 randomly selected participants, which, posthoc, presented a representative distribution of obstetric complications. Complete agreement was achieved when women were asked whether they had previous NPs or HPs and term or preterm births; for the number of reproductive complications (per woman), the intraclass correlation coefficient was 0.92 for HPs, 0.87 for preterm births, and 0.85 for weights
2500 g; for age of menarche and menopause, the coefficients were 0.83 and 0.76, respectively, all with a P<0.000. The agreement for newborn weights was analyzed by mixed methods for 2 factors15 in the same 15 women, who had given birth to 52 children; this yielded an intraclass correlation coefficient of 0.90, with a 95% CI of 0.83 to 0.94 for data obtained in a single interview.
| Results |
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1 HP.
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As shown in the Table, the frequency of the smoking habit and of diabetes mellitus did not differ in women with NPs and HPs, whereas hypertension, hyperlipidemia, and a family history of premature CV disease were more frequent in participants with HPs; in addition, body mass index tended to be higher in women with HPs. In concordance with their high CV risk profile, almost half of all of the participants had hemodynamically significant coronary lesions, and approximately half of them had myocardial infarctions; 67% of the infarctions occurred before 65 years of age, thus qualifying as premature CV disease. Neither the frequency nor the duration of hormonal replacement therapy differed between study groups; this was used for >5 years in 6% of the women; of them, 2 were on supplementation at the time of angiography, and 1 had received it for a year at the time of infarction.
Women who had HPs were younger and had later menopause than women who had NPs; those with HPs also had a marked family history of premature atheromatous disease. Women with HPs who presented with myocardial infarction at the time of angiography, or previously, were younger than those with NPs, but the difference did not attain statistical significance.
Regarding the number of stenotic coronary arteries, no significant differences were observed among the NP and HP groups. According to a Poisson regression analysis of the correlation between age and the number of diseased coronary vessels, the mean number of stenotic arteries increased in both groups with age (P=0.006); however, the logarithm of the 10-year progression of the number of stenosed arteries was 28% per 10 years in HPs and 22% in NPs (P=0.034; Figure 1).
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With respect to obstetric outcomes (Table), apart from the 33.7% of the participants with HPs, a high percentage of women had spontaneous abortions, preterm births, and infants with low birth weight. Women with preterm births and infants with low birth weights prevailed in the HPs, whereas women with spontaneous abortions tended to increase in HPs. Other pregnancy complications, such as gestational diabetes, recurrent abortions, intrahepatic cholestasis, placenta previa, ectopic pregnancy, and placenta abruptio, were observed in 1% to 8% of women; only 1 woman presented eclampsia. No significant differences were observed between HPs and NPs in the rates of these complications. Only 39 women in the entire study group had impeccable reproductive histories.
In the multivariate analysis, coronary artery disease was nonsignificantly associated with HPs but showed a significant association with diabetes mellitus, a family history of premature CV disease, and current smoking (Figure 2). HPs were associated in the univariate analysis with a higher likelihood of a familial premature CV disease (odds ratio [OR]: 2.8; CI: 1.5 to 5.2) and in the multivariate analysis with future hypertension (OR: 4.4, CI: 1.5 to 12.5) and a border line significance with hyperlipidemia (OR: 1.9, CI: 0.96 to 4.1).
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Despite using an unbiased selection for contacting and excluding study participants, we wished to characterize women who underwent angiography but were not included in the analysis. These women did not differ from the study group in body mass index (27.4±4.6) and in the frequency of hypertension (82%), diabetes mellitus (33%), presence of coronary lesions (53%), and myocardial infarctions (32%). Although age and the number of stenotic coronary arteries were higher among these women (62.7±11.3 years and 0.9±1.1 arteries per woman; P=0.059) than among the participants, this difference did not attain statistical significance (P=0.058 and P=0.059, respectively).
| Discussion |
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The main strength of this study was the use of selective angiography, the gold standard to define coronary disease; these angiographies permitted testing of the association of remote HPs with a wide range of coronary conditions, from intact arterial beds to multiple vessel disease, as well as with the sequelae of myocardial infarctions. Another advantage derived from a relative lack of interventions, as apart from the previous management of hypertension and diabetes mellitus, hyperlipidemia was diagnosed and smoking eliminated once the angiographies had been performed. Lastly, the participants presented a high frequency of CV risk factors, exceeding the prevalences observed in similar age groups in the Chilean population,16 which explains the magnitude and early onset of coronary disease; it is likely that this contributed several decades in advance to a high incidence of obstetric complications, similar to that reported recently by Catov et al17 for a group with marked CV risks.
The most important limitation of the study is that the obstetric complications, the mainstay for categorizing the participants, were obtained by maternal recall. In spite of this, we believe that the reliability of the obstetric data was high based on the complete agreement obtained in a subgroup of randomly selected participants when asked in 2 separate interviews whether they had HPs, preterm births, and low birth weight infants. In addition, the numbers of these same complications per women were similar in both interviews. Moreover, a concordance of 0.90 was obtained for recalled birth weight of all of the infants, within the range observed by Catov et al.18 We attribute the good reproducibility to double checking within the interview, a precaution that increases sensitivity and specificity,11,19 to the time spent in the interview, and to the fact that women were asked about HPs, a term that has yielded a higher agreement than preeclampsia, an unfamiliar medical term.19–21 However, because the concordance for the age of menopause was intermediate, this parameter was excluded from the multivariate analysis. A bias to report false-positive HPs among women with chronic hypertension would have diluted the association between HPs and coronary artery disease.
Another limitation of this study is the lack of characterization of the different presentations of hypertension in pregnancy. Because the need for a precise definition of HPs in the clinical setting to be used for research purposes has been reinforced rather recently,22 it is highly likely that medical charts lacked an accurate diagnosis in a significant number of patients. Similarly, the presence of CV risk factors during the reproductive years may not have been evaluated in most of these patients, because the impact of such factors on gestation has been evident only recently.23–31 Some reports do not differentiate between types of HPs,7,11 and others show a greater association between preeclampsia and CV disease.1,4,5,8,9 Based on these latter studies, our failure to characterize the different forms of HPs could have blunted their impact on coronary disease.
It might be argued that the 3-year difference with which women with previous HPs were submitted to coronary angiograms and the 6% increase in stenotic vessels over a 10-year period observed in them as compared with women with previous NPs (28% versus 22%) are smaller than the relative risks attributed previously to HPs. However, greater incidence of CV disease after HPs has been reported with shorter follow-up32 and in younger women.1 A weaker association than that estimated by previous reports could also be accounted for by the possibility of earlier CV deaths associated with HPs. Finally, we must be aware that this study was focused on identifying atheromatous plaques in the major coronary arteries and has missed coronary microvascular and/or endothelial dysfunction, which should be especially considered in the women with myocardial ischemia and nonobstructive or absent coronary lesions33; thus, endothelial dysfunction could represent the persistence of a condition found after a preeclamptic pregnancy,34,35 in addition to being the initial stage of the atheromatous lesions. Even so, with the current difficulties in the evaluation, diagnosis, and management of coronary disease in women,36 the clinical impact of even the small temporal differences found by us may be amplified, making the remote prognosis of HPs an important public health issue.
The lack of a significant relative risk between coronary disease and HPs could be influenced by the power of the present study. However, the risk posed by familial premature disease in both conditions supports the role of common intermediate mediators. Because CV risk factors increase along a continuum, it is likely that our study group had accrued, during their reproductive years, incipient circulating and functional CV risks and even vascular morphological changes.37–43 This hypothesis is supported by a significant association of hypertension in pregnancy with chronic hypertension and by a borderline association with hyperlipidemia late in life. It is highly likely that conventional, arbitrary blood pressure cutoffs may not be valid in the face of the metabolic, hemodynamic, and immunologic challenges posed to the pregnant mother, as demonstrated by the association of preeclampsia with high-normal blood pressures.27 Based on the hypothesis that hypertension in pregnancy expresses underlying maternal conditions, we propose that proteinuric versus nonproteinuric HPs relate to CV complications through 2 different pathophysiologic pathways. In proteinuric HP (ie, preeclampsia), there may be an underlying endothelial dysfunction because of CV risk factors,23–32,34,35,37–43 which is exacerbated and clinically expressed by increased syncytiotrophoblast debris shedded into the maternal circulation.44–50 In nonproteinuric HP (ie, transient hypertension or exacerbation of an underlying hypertension), there is a restricted capacity to stimulate vasodilatory and antiaggregating factors (eg, prostacyclin,51 tissue kallikrein,52 and angiotensin-[1-7]53); this limitation hampers the adaptation to the systemic hemodynamic changes of pregnancy54–57 and may favor CV disease later in life.
We believe that the finding of earlier angiographic coronary lesions in women who reported HPs adds a piece to the puzzle initiated by the registry-based cohort follow-up. Further studies are needed in women undergoing coronary angiography, which should ideally be matched to their remote obstetric records, to test whether the present findings may be extended to populations of different ages and ethnicities. In addition, diagnostic tests for coronary microvascular and/or endothelial dysfunction should be incorporated in future studies.
Perspectives
This study confirms the link between HPs and CV disease and emphasizes the need to detect clinical and biochemical markers of CV risks before gestation. Such early detection would allow primary prevention of CV disease, and possibly prediction and early management of gestational complications. The awareness that pregnancy represents a CV "stress test" should reinforce early management of CV risks in women presenting an abnormal response, leading to effective prevention or a delay of CV disease.
| Acknowledgments |
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Sources of Funding
This study was partly supported by grant 1080228 from Fondo Nacional de Ciencia y Tecnología (Fondecyt), Chile. F.Q. and A.v.S. received a grant for medical students participating in elective research programs of the Pontificia Universidad Católica School of Medicine.
Disclosures
None.
Received November 25, 2008; first decision December 19, 2008; accepted January 18, 2009.
| References |
|---|
|
|
|---|
2. Hannaford P, Ferry S, Hirsch S. Cardiovascular sequelae of toxaemia of pregnancy. Heart. 1997; 77: 154–158.
3. Smith GC, Pell JP, Walsh D. Pregnancy complications and maternal risk of ischaemic heart disease: a retrospective cohort study of 129,290 births. Lancet. 2001; 357: 2002–2006.[CrossRef][Medline] [Order article via Infotrieve]
4. Wilson BJ, Watson MS, Prescott GJ, Sunderland S, Campbell DM, Hannaford P, Smith WC. Hypertensive diseases of pregnancy and risk of hypertension and stroke in later life: results from cohort study. BMJ. 2003; 326: 845–849.
5. Kestenbaum B, Seliger SL, Easterling TR, Gillen DL, Critchlow CW, Stehman-Breen CO, Schwartz SM. Cardiovascular and thromboembolic events following hypertensive pregnancy. Am J Kidney Dis. 2003; 42: 982–989.[Medline] [Order article via Infotrieve]
6. Pell JP, Smith GC, Walsh D. Pregnancy complications and subsequent maternal cerebrovascular events: a retrospective cohort study of 119,668 births. Am J Epidemiol. 2004; 159: 336–342.
7. Arnadottir GA, Geirsson RT, Arngrimsson R, Jonsdottir LS, Olafsson O. Cardiovascular death in women who had hypertension in pregnancy: a case-control study. BJOG. 2005; 112: 286–292.[CrossRef][Medline] [Order article via Infotrieve]
8. Haukkamaa L, Salminen M, Laivuori H, Leinonen H, Hiilesmaa V, Kaaja R. Risk for subsequent coronary artery disease after preeclampsia. Am J Cardiol. 2004; 93: 805–808.[CrossRef][Medline] [Order article via Infotrieve]
9. Bellamy L, Casas JP, Hingorani AD, Williams DJ. Pre-eclampsia and risk of cardiovascular disease and cancer in later life: Systematic review and meta-analysis. BMJ. 2007; 335: 974.
10. Catov JM, Newman AB, Roberts JM, Kelsey SF, Sutton-Tyrrell K, Harris TB, Colbert L, Rubin SM, Satterfield S, Ness RB. Preterm delivery and later maternal cardiovascular disease risk. Epidemiology. 2007; 18: 733–739.[CrossRef][Medline] [Order article via Infotrieve]
11. Sabour S, Franx A, Rutten A, Grobbee DE, Prokop M, Bartelink ML, van der Schouw YT, Bots ML. High blood pressure in pregnancy and coronary calcification. Hypertension. 2007; 49: 813–817.
12. Irgens HU, Reisaeter L, Irgens LM, Lie RT. Long term mortality of mothers and fathers after pre-eclampsia: population based cohort study. BMJ. 2001; 323: 1213–1217.
13. Rocco P, Morales C, Moraga M, Miquel JF, Nervi F, Llop E, Carvallo P, Rothhammer F. Composición genética de la población chilena. Distribución de polimorfismos de DNA mitocondrial en grupos originarios y en la población mixta de Santiago. Rev Med Chil. 2002; 130: 125–131.[Medline] [Order article via Infotrieve]
14. Teo KK, Ounpuu S, Hawken S, Pandey MR, Valentin V, Hunt D, Diaz R, Rashed W, Freeman R, Jiang L, Zhang X, Yusuf S. Tobacco use and risk of myocardial infarction in 52 countries in the interheart study: a case-control study. Lancet. 2006; 368: 647–658.[CrossRef][Medline] [Order article via Infotrieve]
15. McGraw KO, Gordji S, Wong SP. How many subjects to screen? A practical procedure for estimating multivariate normal probabilities for correlated variables. J Consult Clin Psychol. 1994; 62: 960–964.[CrossRef][Medline] [Order article via Infotrieve]
16. Jadue L, Vega J, Escobar MC, Delgado I, Garrido C, Lastra P, Espejo F, Peruga A. Factores de riesgo para las enfermedades no transmisibles: metodología y resultados globales de la encuesta de base del programa CARMEN. Rev Med Chil. 1999; 127: 1004–1013.[Medline] [Order article via Infotrieve]
17. Catov JM, Newman AB, Sutton-Tyrrell K, Harris TB, Tylavsky F, Visser M, Ayonayon HN, Ness RB. Parity and cardiovascular disease risk among older women: how do pregnancy complications mediate the association? Ann Epidemiol. 2008; 18: 873–879.[CrossRef][Medline] [Order article via Infotrieve]
18. Catov JM, Newman AB, Kelsey SF, Roberts JM, Sutton-Tyrrell KC, Garcia M, Ayonayon HN, Tylavsky F, Ness RB. Accuracy and reliability of maternal recall of infant birth weight among older women. Ann Epidemiol. 2006; 16: 429–431.[CrossRef][Medline] [Order article via Infotrieve]
19. Diehl CL, Brost BC, Hogan MC, Elesber AA, Offord KP, Turner ST, Garovic VD. Preeclampsia as a risk factor for cardiovascular disease later in life: validation of a preeclampsia questionnaire. Am J Obstet Gynecol. 2008; 198: e11–e13.[Medline] [Order article via Infotrieve]
20. Sou SC, Chen WJ, Hsieh WS, Jeng SF. Severe obstetric complications and birth characteristics in preterm or term delivery were accurately recalled by mothers. J Clin Epidemiol. 2006; 59: 429–435.[CrossRef][Medline] [Order article via Infotrieve]
21. Yawn BP, Suman VJ, Jacobsen SJ. Maternal recall of distant pregnancy events. J Clin Epidemiol. 1998; 51: 399–405.[CrossRef][Medline] [Order article via Infotrieve]
22. Harlow FH, Brown MA. The diversity of diagnoses of preeclampsia. Hypertens Pregnancy. 2001; 20: 57–67.[Medline] [Order article via Infotrieve]
23. Berends AL, de Groot CJ, Sijbrands EJ, Sie MP, Benneheij SH, Pal R, Heydanus R, Oostra BA, van Duijn CM, Steegers EA. Shared constitutional risks for maternal vascular-related pregnancy complications and future cardiovascular disease. Hypertension. 2008; 51: 1034–1041.
24. Kilic-Okman T, Kucuk M, Ekuklu G. C-reactive protein and body mass index in women with pre-eclampsia. Int J Gynaecol Obstet. 2004; 84: 75–76.[CrossRef][Medline] [Order article via Infotrieve]
25. Metzger BE, Lowe LP, Dyer AR, Trimble ER, Chaovarindr U, Coustan DR, Hadden DR, McCance DR, Hod M, McIntyre HD, Oats JJ, Persson B, Rogers MS, Sacks DA. Hyperglycemia and adverse pregnancy outcomes. N Engl J Med. 2008; 358: 1991–2002.
26. Walsh SW. Obesity: a risk factor for preeclampsia. Trends Endocrinol Metab. 2007; 18: 365–370.[CrossRef][Medline] [Order article via Infotrieve]
27. Magnussen EB, Vatten LJ, Lund-Nilsen TI, Salvesen KA, Davey Smith G, Romundstad PR. Prepregnancy cardiovascular risk factors as predictors of pre-eclampsia: population based cohort study. BMJ. 2007; 335: 978–986.
28. Roes EM, Sieben R, Raijmakers MT, Peters WH, Steegers EA. Severe preeclampsia is associated with a positive family history of hypertension and hypercholesterolemia. Hypertens Pregnancy. 2005; 24: 259–271.[CrossRef][Medline] [Order article via Infotrieve]
29. Qiu C, Williams MA, Leisenring WM, Sorensen TK, Frederick IO, Dempsey JC, Luthy DA. Family history of hypertension and type 2 diabetes in relation to preeclampsia risk. Hypertension. 2003; 41: 408–413.
30. Sibai BM, Gordon T, Thom E, Caritis SN, Klebanoff M, McNellis D, Paul RH. Risk factors for preeclampsia in healthy nulliparous women: a prospective multicenter study. The National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units. Am J Obstet Gynecol. 1995; 172: 642–648.[CrossRef][Medline] [Order article via Infotrieve]
31. Arbogast BW, Leeper SC, Merrick RD, Olive KE, Taylor RN. Which plasma factors bring about disturbance of endothelial function in pre-eclampsia? Lancet. 1994; 343: 340–341.[CrossRef][Medline] [Order article via Infotrieve]
32. Sibai BM. Intergenerational factors: a missing link for preeclampsia, fetal growth restriction, and cardiovascular disease? Hypertension. 2008; 51: 993–994.
33. von Mering GO, Arant CB, Wessel TR, McGorray SP, Bairey Merz CN, Sharaf BL, Smith KM, Olson MB, Johnson BD, Sopko G, Handberg E, Pepíne CJ, Kerensky RA. Abnormal coronary vasomotion as a prognostic indicator of cardiovascular events in women: results from the National Heart, Lung, and Blood Institute-Sponsored Womens Ischemia Syndrome Evaluation (WISE). Circulation. 2004; 109: 722–725.
34. Chambers JC, Fusi L, Malik IS, Haskard DO, De Swiet M, Kooner JS. Association of maternal endothelial dysfunction with preeclampsia. JAMA. 2001; 285: 1607–1612.
35. Germain AM, Romanik MC, Guerra I, Solari S, Reyes MS, Johnson RJ, Price K, Karumanchi SA, Valdés G. Endothelial dysfunction: a link among preeclampsia, recurrent pregnancy loss and future cardiovascular events? Hypertension. 2007; 49: 90–95.
36. Wenger NK, Shaw LJ, Vaccarino V. Coronary heart disease in women: update 2008. Clin Pharmacol Ther. 2008; 83: 37–51.[CrossRef][Medline] [Order article via Infotrieve]
37. Anastasakis E, Paraskevas KI, Papantoniou N, Daskalakis G, Mesogitis S, Mikhailidis D, Antsaklis A. Association between abnormal uterine artery doppler flow velocimetry, risk of preeclampsia, and indices of arterial structure and function: a pilot study. Angiology. 2008; 59: 493–499.[CrossRef][Medline] [Order article via Infotrieve]
38. Vasapollo B, Novelli GP, Valensise H. Total vascular resistance and left ventricular morphology as screening tools for complications in pregnancy. Hypertension. 2008; 51: 1020–1026.
39. Bartha JL, Gonzalez-Bugatto F, Fernandez-Macias R, Gonzalez-Gonzalez NL, Comino-Delgado R, Hervias-Vivancos B. Metabolic syndrome in normal and complicated pregnancies. Eur J Obstet Gynecol Reprod Biol. 2008; 137: 178–184.[CrossRef][Medline] [Order article via Infotrieve]
40. Conde-Agudelo A, Villar J, Lindheimer M. Maternal infection and risk of preeclampsia: systematic review and metaanalysis. Am J Obstet Gynecol. 2008; 198: 7–22.[CrossRef][Medline] [Order article via Infotrieve]
41. Kaaja R, Laivuori H, Laakso M, Tikkanen MJ, Ylikorkala O. Evidence of a state of increased insulin resistance in preeclampsia. Metabolism. 1999; 48: 892–896.[CrossRef][Medline] [Order article via Infotrieve]
42. King JC. Maternal obesity, metabolism, and pregnancy outcomes. Annu Rev Nutr. 2006; 26: 271–291.[CrossRef][Medline] [Order article via Infotrieve]
43. Manten GT, Sikkema MJ, Voorbij HA, Visser GH, Bruinse HW, Franx A. Risk factors for cardiovascular disease in women with a history of pregnancy complicated by preeclampsia or intrauterine growth restriction. Hypertens Pregnancy. 2007; 26: 39–50.[CrossRef][Medline] [Order article via Infotrieve]
44. Davison JM, Homuth V, Jeyabalan A, Conrad KP, Karumanchi SA, Quaggin S, Dechend R, Luft FC. New aspects in the pathophysiology of preeclampsia. J Am Soc Nephrol. 2004; 15: 2440–2448.
45. Goswami D, Tannetta DS, Magee LA, Fuchisawa A, Redman CW, Sargent IL, von Dadelszen P. Excess syncytiotrophoblast microparticle shedding is a feature of early-onset pre-eclampsia, but not normotensive intrauterine growth restriction. Placenta. 2006; 27: 56–61.[Medline] [Order article via Infotrieve]
46. Huppertz B. Placental origins of preeclampsia: challenging the current hypothesis. Hypertension. 2008; 51: 970–975.
47. Huppertz B, Kingdom J, Caniggia I, Desoye G, Black S, Korr H, Kaufmann P. Hypoxia favours necrotic versus apoptotic shedding of placental syncytiotrophoblast into the maternal circulation. Placenta. 2003; 24: 181–190.[CrossRef][Medline] [Order article via Infotrieve]
48. Redman CW, Sargent IL. Placental debris, oxidative stress and pre-eclampsia. Placenta. 2000; 21: 597–602.[CrossRef][Medline] [Order article via Infotrieve]
49. Redman CW, Sargent IL. Microparticles and immunomodulation in pregnancy and pre-eclampsia. J Reprod Immunol. 2007; 76: 61–67.[CrossRef][Medline] [Order article via Infotrieve]
50. Redman CW, Sargent IL. Circulating microparticles in normal pregnancy and pre-eclampsia. Placenta. 2008; 29S: 73–77.[CrossRef]
51. Fitzgerald DJ, Entman SS, Mulloy K, FitzGerald GA. Decreased prostacyclin biosynthesis preceding the clinical manifestation of pregnancy-induced hypertension. Circulation. 1987; 75: 956–963.
52. Elebute OA, Mills IH. Urinary kallikrein in normal and hypertensive pregnancies. Perspect Nephrol Hypertens. 1976; 5: 329–338.[Medline] [Order article via Infotrieve]
53. Brosnihan KB, Neves LA, Anton L, Joyner J, Valdes G, Merrill DC. Enhanced expression of Ang-(1-7) during pregnancy. Braz J Med Biol Res. 2004; 37: 1255–1262.[Medline] [Order article via Infotrieve]
54. Hytten F. Blood volume changes in normal pregnancy. Clin Haematol. 1985; 14: 601–612.[Medline] [Order article via Infotrieve]
55. Rosso P, Donoso E, Braun S, Espinoza R, Fernandez C, Salas SP. Maternal hemodynamic adjustments in idiopathic fetal growth retardation. Gynecol Obstet Invest. 1993; 35: 162–165.[CrossRef][Medline] [Order article via Infotrieve]
56. Sala C, Campise M, Ambroso G, Motta T, Zanchetti A, Morganti A. Atrial natriuretic peptide and hemodynamic changes during normal human pregnancy. Hypertension. 1995; 25: 631–636.
57. Wilson M, Morganti AA, Zervoudakis I, Letcher RL, Romney BM, Von Oeyon P, Papera S, Sealey JE, Laragh JH. Blood pressure, the renin-aldosterone system and sex steroids throughout normal pregnancy. Am J Med. 1980; 68: 97–104.[CrossRef][Medline] [Order article via Infotrieve]
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