Flow mediated vasodilation and circulating concentrations of high sensitive C-reactive protein, interleukin-6 and tumor necrosis factor-alpha in normal pregnancy--The Cardiovascular Risk in Young Finns Study

The Importance of Nontraditional and Sex-Specific Risk Factors in Young Women With Vasomotor Nonobstructive vs Obstructive Coronary Syndromes

Background

Heart disease is the leading cause of premature death for women in Canada. Ischemic heart disease is categorized as myocardial infarction (MI) with no obstructive coronary artery disease (MINOCA), ischemia with no obstructive coronary arteries (INOCA), and atherosclerotic obstructive coronary artery disease (CAD) with MI (MI-CAD) or without MI (non-MI-CAD). This study aims to study the prevalence of traditional and nontraditional ischemic heart disease risk factors and their relationships with (M)INOCA, compared to MI-CAD and non-MI-CAD in young women.

Methods

This study investigated women who presented with premature (at age ≤ 55 years) vasomotor entities of (M)INOCA or obstructive CAD confirmed by coronary angiography, who are currently enrolled in either the Leslie Diamond Women's Heart Health Clinic Registry (WHC) or the Study to Avoid Cardiovascular Events in British Columbia (SAVEBC). Univariable and multivariable regression models were applied to investigate associations of risk factors with odds of (M)INOCA, MI-CAD, and non-MI-CAD.

Results

A total of 254 women enrolled between 2015 and 2022 were analyzed, as follows: 77 with INOCA and 37 with MINOCA from the registry, and 66 with non-MI-CAD and 74 with MI-CAD from the study. Regression analyses demonstrated that migraines and preeclampsia or gestational hypertension were the most significant risk factors, with a higher likelihood of being associated with premature (M)INOCA, relative to obstructive CAD. Conversely, the presence of diabetes and a current or previous smoking history had the highest likelihood of being associated with premature CAD.

Conclusions

The risk factor profiles of patients with premature (M)INOCA, compared to obstructive CAD, have significant differences.

Long-term cardiovascular mortality in women with twin pregnancies by lifetime reproductive history

BACKGROUND

Women with one lifetime singleton pregnancy have increased risk of cardiovascular disease (CVD) mortality compared with women who continue reproduction particularly if the pregnancy had complications. Women with twins have higher risk of pregnancy complications, but CVD mortality risk in women with twin pregnancies has not been fully described.

OBJECTIVES

We estimated risk of long-term CVD mortality in women with naturally conceived twins compared to women with singleton pregnancies, accounting for lifetime number of pregnancies and pregnancy complications.

METHODS

Using linked data from the Medical Birth Registry of Norway and the Norwegian Cause of Death Registry, we identified 974,892 women with first pregnancy registered between 1967 and 2013, followed to 2020. Adjusted hazard ratios (aHR) with 95% confidence intervals (CI) for maternal CVD mortality were estimated by Cox regression for various reproductive history (exposure categories): (1) Only one twin pregnancy, (2) Only one singleton pregnancy, (3) Only two singleton pregnancies, (4) A first twin pregnancy and continued reproduction, (5) A first singleton pregnancy and twins in later reproduction and (6) Three singleton pregnancies (the referent group). Exposure categories were also stratified by pregnancy complications (pre-eclampsia, preterm delivery or perinatal loss).

RESULTS

Women with one lifetime pregnancy, twin or singleton, had increased risk of CVD mortality (adjusted hazard [HR] 1.72, 95% confidence interval [CI] 1.21, 2.43 and aHR 1.92, 95% CI 1.78, 2.07, respectively), compared with the referent of three singleton pregnancies. The hazard ratios for CVD mortality among women with one lifetime pregnancy with any complication were 2.36 (95% CI 1.49, 3.71) and 3.56 (95% CI 3.12, 4.06) for twins and singletons, respectively.

CONCLUSIONS

Women with only one pregnancy, twin or singleton, had increased long-term CVD mortality, however highest in women with singletons. In addition, twin mothers who continued reproduction had similar CVD mortality compared to women with three singleton pregnancies.

Endothelial function and concentrations of high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-alpha during a long agonist IVF protocol

We examined possible changes in endothelial function during a long agonist in vitro fertilization (IVF) protocol. We measured flow-mediated dilatation (FMD) and FMD percent (FMD%) from the brachial artery and plasma levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-〈). We studied longitudinally three time points in 27 women undergoing a long agonist IVF treatment at Kuopio University Hospital. The first visit was at the beginning of their period (low estradiol). The other two visits were during gonadotrophin-releasing hormone (GnRH) analog downregulation (low estradiol) and at the end of follicle-stimulating hormone (FSH) stimulation (high estradiol). The first visit was used as the reference, and the women served as their own controls. During the stimulation protocol, FMD and FMD% remained. Toward the end of stimulation, hsCRP (P = 0.003), IL-6 (P = 0.04), and TNF-〈 (P = 0.008) concentrations all decreased, while estradiol levels increased (P < 0.001). Correlations between estradiol and proinflammatory factors or FMD were, however, non-significant. The only significant correlation appeared between FMD% and hsCRP at Visit 2 (r = 0.485, P = 0.01). In conclusion, IVF stimulation promoted no change in endothelial function, whereas hsCRP, IL-6, and TNF-〈 decreased. These findings indicate that estrogen may improve the cytokine profile among healthy women undergoing IVF, but this is not reflected in endothelial function.

Maternal Serum Cytokine Concentrations in Healthy Pregnancy and Preeclampsia

The maternal immune response is essential for successful pregnancy, promoting immune tolerance to the fetus while maintaining innate and adaptive immunity. Uncontrolled, increased proinflammatory responses are a contributing factor to the pathogenesis of preeclampsia. The Th1/Th2 cytokine shift theory, characterised by bias production of Th2 anti-inflammatory cytokine midgestation, was frequently used to reflect the maternal immune response in pregnancy. This theory is simplistic as it is based on limited information and does not consider the role of other T cell subsets, Th17 and Tregs. A range of maternal peripheral cytokines have been measured in pregnancy cohorts, albeit the changes in individual cytokine concentrations across gestation is not well summarised. Using available data, this review was aimed at summarising changes in individual maternal serum cytokine concentrations throughout healthy pregnancy and evaluating their association with preeclampsia. We report that TNF-α increases as pregnancy progresses, IL-8 decreases in the second trimester, and IL-4 concentrations remain consistent throughout gestation. Lower second trimester IL-10 concentrations may be an early predictor for developing preeclampsia. Proinflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-8, and IL-6) are significantly elevated in preeclampsia. More research is required to determine the usefulness of using cytokines, particularly IL-10, as early biomarkers of pregnancy health.

Mechanisms of Sex Disparities in Cardiovascular Function and Remodeling

Epidemiological studies demonstrate disparities between men and women in cardiovascular disease prevalence, clinical symptoms, treatments, and outcomes. Enrollment of women in clinical trials is lower than men, and experimental studies investigating molecular mechanisms and efficacy of certain therapeutics in cardiovascular disease have been primarily conducted in male animals. These practices bias data interpretation and limit the implication of research findings in female clinical populations. This review will focus on the biological origins of sex differences in cardiovascular physiology, health, and disease, with an emphasis on the sex hormones, estrogen and testosterone. First, we will briefly discuss epidemiological evidence of sex disparities in cardiovascular disease prevalence and clinical manifestation. Second, we will describe studies suggesting sexual dimorphism in normal cardiovascular function from fetal life to older age. Third, we will summarize and critically discuss the current literature regarding the molecular mechanisms underlying the effects of estrogens and androgens on cardiac and vascular physiology and the contribution of these hormones to sex differences in cardiovascular disease. Fourth, we will present cardiovascular disease risk factors that are positively associated with the female sex, and thus, contributing to increased cardiovascular risk in women. We conclude that inclusion of both men and women in the investigation of the role of estrogens and androgens in cardiovascular physiology will advance our understanding of the mechanisms underlying sex differences in cardiovascular disease. In addition, investigating the role of sex-specific factors in the development of cardiovascular disease will reduce sex and gender disparities in the treatment and diagnosis of cardiovascular disease. © 2019 American Physiological Society. Compr Physiol 9:375-411, 2019.

The influence of prenatal exercise and pre-eclampsia on maternal vascular function

During healthy pregnancy, the cardiovascular system undergoes diverse adaptations to support adequate transfer of oxygen and nutrients from mother to fetus. In order to accommodate the large expansion of blood volume and associated cardiac output, the structure, mechanics, and function of the arteries are altered. Specifically, in healthy pregnancy there is a remodeling of arteries (increased angiogenesis and vasodilation), a generalized reduction in arterial stiffness (increased compliance), and an enhanced endothelial function. The development of pregnancy complications, specifically pre-eclampsia, is associated with poor placentation (decreased angiogenesis), increased arterial stiffness, and vascular dysfunction (reduced endothelial function). Many of the positive adaptations that occur in healthy pregnancy are enhanced in response to chronic exercise. Specifically, placental angiogenesis and endothelial function have been shown to improve to a greater extent in women who are active during their pregnancy compared with those who are not. Prenatal exercise may be important in helping to reduce the risk of vascular dysfunction in pregnancy. However, our knowledge of the vascular adaptations resulting from maternal exercise is limited. This review highlights maternal vascular adaptations occurring during healthy pregnancy, and contrasts the vascular maladaptation associated with pre-eclampsia. Finally, we discuss the role of prenatal exercise on vascular function in the potential prevention of vascular complications associated with pre-eclampsia.

The effect of an antenatal lifestyle intervention in overweight and obese women on circulating cardiometabolic and inflammatory biomarkers: secondary analyses from the LIMIT randomised trial

BACKGROUND

Maternal overweight and obesity during pregnancy is associated with insulin resistance, hyperglycaemia, hyperlipidaemia and a low-grade state of chronic inflammation. The aim of this pre-specified analysis of secondary outcome measures was to evaluate the effect of providing antenatal dietary and lifestyle advice on cardiometabolic and inflammatory biomarkers.

METHODS

We conducted a multicentre trial in which pregnant women who were overweight or obese were randomised to receive either Lifestyle Advice or Standard Care. We report a range of pre-specified secondary maternal and newborn cardiometabolic and inflammatory biomarker outcomes. Maternal whole venous blood was collected at trial entry (mean 14 weeks gestation; non-fasting), at 28 weeks gestation (fasting), and at 36 weeks gestation (non-fasting). Cord blood was collected after birth and prior to the delivery of the placenta. A range of cardiometabolic and inflammatory markers were analysed (total cholesterol, triglycerides, non-esterified fatty acids, high-density lipoprotein cholesterol, insulin, glucose, leptin, adiponectin, C-reactive protein, granulocyte macrophage-colony stimulating factor, interferon gamma, TNF-α, and interleukins 1β, 2, 4, 5, 6, 8, and 10). Participants were analysed in the groups to which they were randomised, and were included in the analyses if they had a measure at any time point.

RESULTS

One or more biological specimens were available from 1951 women (989 Lifestyle Advice and 962 Standard Care), with cord blood from 1174 infants (596 Lifestyle Advice and 578 Standard Care). There were no statistically significant differences in mean cardiometabolic and inflammatory marker concentrations across pregnancy and in infant cord blood between treatment groups. Estimated treatment group differences were close to zero, with 95% confidence intervals spanning a range of differences that were short of clinical relevance. There was no evidence to suggest that the intervention effect was modified by maternal BMI category.

CONCLUSIONS

Despite our findings, it will be worth considering potential relationships between cardiometabolic and inflammatory markers and clinical outcomes, including longer-term infant health and adiposity.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ( ACTRN12607000161426 ; Date Registered 09/03/2007).

Longitudinal study of vascular structure and function during normal pregnancy

OBJECTIVE

To examine alterations in maternal vascular structure and function during normal pregnancy.

METHODS

We assessed brachial and central blood pressure, pulse-wave velocity and augmentation index (by pulse-wave analysis and applanation tonometry), common carotid artery structure (by ultrasonography) and endothelial function in the brachial artery (by postischemic hyperemia-induced flow-mediated vasodilatation by glyceryl trinitrate) and in the forearm skin microcirculation (by laser Doppler perfusion imaging during iontophoretic administration of acetylcholine and sodium nitroprusside) in 52 healthy nulliparous women at 14, 24 and 34 weeks' gestation, and at 9 months postpartum.

RESULTS

During pregnancy, brachial and central systolic and diastolic blood pressures initially decreased but subsequently increased (all P < 0.05). Flow-mediated vasodilatation in the brachial artery increased during early pregnancy (P < 0.05), whereas non-specific vasodilatation by glyceryl trinitrate decreased (P < 0.01), indicating improved endothelial function. Thus, endothelial function index (forearm blood flow/glyceryl trinitrate) increased during pregnancy (0.30 ± 0.18 in the non-pregnant state at 9 months postpartum and 0.51 ± 0.19, 0.61 ± 0.39 and 0.49 ± 0.30 in the first, second and third trimesters, respectively) (P < 0.001). Endothelium-dependent skin microvascular reactivity to acetylcholine also increased (P < 0.01). Carotid-femoral pulse-wave velocity decreased during pregnancy (5.88 ± 0.91 m/s in the non-pregnant state and 5.55 ± 0.67, 5.12 ± 0.66 and 5.62 ± 0.74 m/s in the first, second and third trimesters, respectively) (P < 0.001).

CONCLUSION

During normal pregnancy, the blood volume expansion necessary for sufficient fetal growth is accommodated by early and marked changes in the matvascular system. This seems to be dependent on normal adaptive endothelial and vascular function. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Parity and Cardiovascular Disease Mortality: a Dose-Response Meta-Analysis of Cohort Studies

Parity has been shown to inversely associate with cardiovascular disease (CVD) mortality, but the evidence of epidemiological studies is still controversial. Therefore, we quantitatively assessed the relationship between parity and CVD mortality by summarizing the evidence from prospective studies. We searched MEDLINE (PubMed), EMBASE and ISI Web of Science databases for relevant prospective studies of parity and CVD mortality through the end of March 2015. Fixed- or random-effects models were used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). Heterogeneity among studies was assessed using the I² statistics. All statistical tests were two-sided. Ten prospective studies were included with a total of 994,810 participants and 16,601 CVD events. A borderline significant inverse association was observed while comparing parity with nulliparous, with summarized RR = 0.79 (95% CI: 0.60–1.06; I² = 90.9%, P < 0.001). In dose-response analysis, we observed a significant nonlinear association between parity number and CVD mortality. The greatest risk reduction appeared when the parity number reached four. The findings of this meta-analysis suggests that ever parity is inversely related to CVD mortality. Furthermore, there is a statistically significant nonlinear inverse association between parity number and CVD mortality.

Factors associated with maternal serum C-reactive protein throughout pregnancy: A longitudinal study in women of Rio de Janeiro, Brazil

OBJECTIVES

The aim of this study was to evaluate the longitudinal changes of C-reactive protein (CRP) concentrations during pregnancy and to assess whether socioeconomic, anthropometric, dietary, behavioral, and biochemical factors are associated with these changes.

METHODS

This was a prospective cohort study of 115 adult pregnant women, followed at gestational weeks 5 to 13, 20 to 26, and 30 to 36. Serum concentrations of CRP (mg/L) were measured by the immunoturbidimetric method with ultrasensitive kits (sensitivity 0.05 mg/dL). The statistics included descriptive analysis (mean + SD) and longitudinal linear mixed-effects models, reporting the β coefficient and 95% confidence intervals (CI).

RESULTS

Serum CRP concentrations progressively increased throughout pregnancy (β = 0.121; 95% CI, 0.071-0.171). Parity (β = 1.579; 95% CI, 0.731-2.427) and prepregnancy body mass index (BMI) (β = 0.316; 95% CI, 0.053-0.587) were positively associated and dietary glycemic load was negatively associated (β = -0.203; 95% CI, -0.380 to -0.026) with CRP concentrations in the multiple model. Prepregnancy obese women presented a more pronounced increase of CRP concentrations compared with normal weight women (β = 0.210; 95% CI, 0.059-0.360 versus 0.115, respectively; 95% CI, 0.049-0.181). A statistically significant interaction was observed between parity and gestational age (β = -0.045; 95% CI, -0.084 to -0.005), indicating that the variation of CRP throughout pregnancy differed according to parity categories.

CONCLUSION

CRP concentrations increased throughout pregnancy. Parity and prepregnancy BMI were positively associated and dietary glycemic load was negatively associated with concentrations of CRP.

Perinatal stress, fatigue, depressive symptoms, and immune modulation in late pregnancy and one month postpartum

Stress and fatigue are common complaints of pregnant and postpartum women as is depression. These symptoms may be related to immunomodulation. However, few studies have examined these relationships. The aim of this study was to examine the relationships among stress, fatigue, depression, and cytokines as markers of immune modulation in prenatal and postpartum women. Women completed questionnaires and gave blood samples during late pregnancy and again at 4–6 weeks postpartum. Blood was analyzed for cytokines as measures of immune modulation. Stress, fatigue, and depression were experienced at moderately high levels, with higher levels of fatigue and depression in the postpartum but higher stress in the prenatal period. Levels of several cytokines were increased in the postpartum over the prenatal period. Stress and depression were related in the prenatal period and stress, depression, and fatigue were related in the postpartum. While various cytokines were related to each other in both periods, only stress was related to MIP-1β, a cytokine that may be important for childbirth processes. More studies, especially longitudinal and interventional studies, are needed to increase our knowledge about etiology, patterns, symptoms, factors, and management of maternal distress. The search for reliable biomarkers for at-risk mothers remains a priority.

C-reactive protein by pregnancy and lactational status among Filipino young adult women

OBJECTIVES

Pregnancy and lactation involve adaptations in immune regulation, but little is known about cross-cultural variation in inflammatory changes during pregnancy or lactation. Here we report concentrations of C-reactive protein (CRP) in a large cross-sectional sample of healthy Filipino women who vary in parity, gestational, and lactational status, and who come from a population previously described as having low CRP.

METHODS

Fasting plasma CRP was measured among female participants (ages 20.8-22.4 years) in the Cebu Longitudinal Health and Nutrition Survey (n = 822).

RESULTS

Median CRP was 0.2 mg/l in nulliparous women and peaked at 2.0 mg/l in women in their 3rd trimester of pregnancy. Parous but post-partum women had higher CRP compared to nulliparous women, which was largely explained by body composition differences as reflected in waist circumference and skinfold measures. Among post-partum women with infants, CRP was similar in women who were currently breastfeeding compared to those who were not.

CONCLUSIONS

At Cebu, women late in gestation have 10-fold higher C-reactive protein compared to nulliparous women, with no evidence that lactation is inflammatory. These population-based findings are similar with findings from prior clinic-based studies and are consistent with the maternal immunological adaptations initiated during pregnancy. The tendency of human females to spend more time than females of other great apes in gestation rather than lactation suggests that the human life history strategy involved increased time spent by reproductively aged females in a pro-inflammatory state.

The association of reproductive history with all-cause and cardiovascular mortality in older women: the Rancho Bernardo Study

OBJECTIVE

To examine associations of gravidity and parity with all-cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in postmenopausal women.

DESIGN

Prospective cohort study.

SETTING

Rancho Bernardo, a southern California community.

PATIENT(S)

One thousand two hundred ninety-four postmenopausal women ages 50-96 who attended a 1984-87 research clinic visit at which reproductive and medical histories were obtained and who were followed through 2007.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

All-cause, CVD, CHD, and non-CHD CVD mortality, determined by nosologist-coded death certificates.

RESULT(S)

Average baseline age was 70.6 ± 9.2. Numbers of pregnancies ranged from 0 to 13 (median = 2); births ranged from 0 to 11 (median = 2). During a median of 19.3 years of follow-up, 707 women (54.6%) died, with 46.5% attributed to CVD, 20.5% to CHD, and 26.0% to non-CHD CVD. Trend analyses showed inverse associations of gravidity with CVD mortality and non-CHD CVD mortality. Women with four or more pregnancies were less likely than nulligravidas to have fatal CVD (hazard ratio [HR] = 0.63, 95% confidence interval [CI] = 0.40-0.99) and non-CHD CVD (HR = 0.48, 95% CI = 0.26-0.91) independent of age, years postmenopause, obesity, and HDL. Associations increased after the first decade of follow-up. Parity and gravidity were not associated with overall or CHD mortality.

CONCLUSION(S)

High gravidity was associated with reduced CVD and non-CHD CVD mortality in postmenopausal women. Protective associations could reflect biological mechanisms that occur with repeated pregnancy or greater social support related to family size among multiparous women.

Psychiatric symptoms and proinflammatory cytokines in pregnancy

OBJECTIVE

Clinical studies suggest that psychiatric symptoms, particularly depression, anxiety, and trauma, may be associated with inflammation, as indexed by proinflammatory cytokines. Such a link may be especially significant in pregnancy and may shed additional light on the etiology of perinatal mood disorders.

METHODS

We prospectively observed 145 women selected from a community obstetric clinic serving a primarily low-income, high-psychosocial risk population. Women without evidence of medical high-risk pregnancies were screened (including psychiatric and trauma histories) and then assessed in detail (e.g., mood symptoms) at approximately 18 and 32 weeks' gestation. Blood was drawn to measure key proinflammatory markers, interleukin 6 and tumor necrosis factor α (TNF-α). Data on pregnancy and obstetric outcome were derived from medical records.

RESULTS

There was considerable stability of cytokine levels within individuals and a significant mean increase across pregnancy observed for interleukin 6 (p < .001) and TNF-α (p < .001). History of trauma was associated with significantly elevated TNF-α levels (F(1,135) = 4.43, p < .05), controlling for psychosocial and obstetric covariates. In contrast, elevated measures of depression and anxiety were unrelated to proinflammatory cytokines (p > .1). Exploratory analyses indicated that neither psychiatric symptoms nor proinflammatory cytokines predicted birth weight, gestational age, or obstetric complications.

CONCLUSIONS

These findings suggest that antecedent trauma may be associated with persistently elevated TNF-α levels during pregnancy. The evidence that a generalized proinflammatory state was associated with symptoms of depression or anxiety in pregnant women was not found.

Association of Insulin Resistance with Serum Interleukin-6 and TNF-α Levels During Normal Pregnancy

Overview:

The purpose of this study was to evaluate the role of Tumor Necrosis Factor-α (TNF-α) in insulin resistance (IR) during normal pregnancy.

Approach:

This cross sectional study was carried out on 86 healthy pregnant women including 26, 23 and 37 individuals in the 1st, 2nd and 3rd trimesters, respectively, and in 21 healthy non pregnant women. Serum TNF-α concentration was measured by Enzyme Linked Immunosorbent Assay (ELISA) method.

Results:

There were significant differences between serum TNF-α and IL-6 levels in pregnant women as compared with maternal healthy controls. There was significant correlation between gestational age and Body Mass Index (BMI) (r = 0.28, P = 0.01). There was no significant correlation between gestational age and insulin resistance (IR). We also did not find correlations between IR and TNF-α and IR and IL-6 in pregnant women.

Conclusion:

In conclusion, our findings suggest that TNF-α and IL-6 are not greatly contributed to pregnancy induced insulin resistance in normal pregnancy.

Childbearing, Child-Rearing, Cardiovascular Risk Factors, and Progression of Carotid Intima-Media Thickness

Background and Purpose— Parity is associated with the risk of clinical cardiovascular events and the severity of preclinical atherosclerosis in older subjects. We sought to determine whether childbearing is associated with concurrent changes in cardiovascular risk factors and the progression of carotid intima-media thickness.

Methods— We examined the association between the number of children born during a 6-year period and concurrent changes in cardiovascular risk factors and progression of carotid intima-media thickness in men and women of reproductive age from the Cardiovascular Risk in Young Finns study. Complete data for parity and carotid intima-media thickness were available for 1786 subjects (1005 females, 781 males).

Results— For females, childbirth during the 6-year follow-up was associated with concurrent reductions in high-density lipoprotein cholesterol ( P trend <0.0001), apolipoprotein A-I ( P trend <0.0001), and apolipoprotein B ( P trend =0.01); a redistribution of adiposity to abdominal deposits; and increased progression of carotid intima-media thickness (7.5±3.2 μm/birth [mean±SEM], P =0.02). The association of childbirth with carotid intima-media thickness progression was not greatly modified by adjustment for concurrent changes in cardiovascular risk factors (fully adjusted: P =0.05). This association was significantly stronger in females than males ( P heterogeneity =0.001), who served as a control group exposed to the social and lifestyle influences of child-rearing but not the biological influences of childbearing.

Conclusions— The progression of carotid atherosclerosis over a 6-year period is increased in females who gave birth during the same period, independent of traditional risk factors. Mechanisms that underlie this observation possibly include parity-induced changes in nontraditional risk factors or an acute influence of pregnancy itself.

Maternal death following cardiopulmonary collapse after delivery: amniotic fluid embolism or septic shock due to intrauterine infection?

PROBLEM

The amniotic fluid embolism (AFE) syndrome is a catastrophic complication of pregnancy frequently associated with maternal death. The causes and mechanisms of disease responsible for this syndrome remain elusive.

METHOD OF STUDY

We report two cases of maternal deaths attributed to AFE: (1) one woman presented with spontaneous labor at term, developed intrapartum fever, and after delivery had sudden cardiovascular collapse and disseminated intravascular coagulation (DIC), leading to death; (2) another woman presented with preterm labor and foul-smelling amniotic fluid, underwent a Cesarean section for fetal distress, and also had postpartum cardiovascular collapse and DIC, leading to death.

RESULTS

Of major importance is that in both cases, the maternal plasma concentration of tumor necrosis factor-alpha at the time of admission to the hospital and when patients had no clinical evidence of infection was in the lethal range (a lethal range is considered to be above 0.1 ng/mL).

CONCLUSION

We propose that subclinical intraamniotic infection may be a cause of postpartum cardiovascular collapse and DIC and resemble AFE. Thus, some patients with the clinical diagnosis of AFE may have infection/systemic inflammation as a mechanism of disease. These observations have implications for the understanding of the mechanisms of disease of patients who develop cardiovascular collapse and DIC, frequently attributed to AFE. It may be possible to identify a subset of patients who have biochemical and immunological evidence of systemic inflammation at the time of admission, and before a catastrophic event occurs.