Maternal nonpregnant vascular function correlates with subsequent fetal growth

Venous Hemodynamic Dysfunction and Recurrent Miscarriage: Case Series and Literature Review

(1) Background: Maternal venous hemodynamic dysfunction is an intrinsic part of the pathophysiology of pre-eclampsia and fetal growth restriction. The aim of this study is to evaluate whether venous hemodynamic dysfunction is present in women with a history of (unexplained) recurrent miscarriage, and to link this pilot observation to reported data in the literature. (2) Methods: A retrospective search of hospital records was conducted to find data on recurrent miscarriage and hemodynamics assessment prior to conception. We also performed a scoping search of the literature regarding the association between recurrent miscarriage and maternal hemodynamics, reproductive outcomes, maternal complications, neonatal complications, and long-term cardiovascular function in women and their offspring. (3) Results: Six out of nine women with a history of recurrent miscarriage had preconception venous hemodynamic dysfunction. This observation is in line with the reported data on reduced venous reserves in association with low plasma volume in women with recurrent miscarriage, and adds to the reported link between recurrent miscarriage, poor reproductive outcomes, and chronic cardiovascular disease. (4) Discussion: This retrospective observational cohort supports an association between venous hemodynamic dysfunction and recurrent miscarriage that is corroborated by data reported in the literature. Abnormal venous hemodynamic function can be improved before conception, and this opens a new and currently unexplored pathway in the management of recurrent miscarriage.

Origins of abnormal placentation: why maternal veins must not be forgotten

The importance of uterine microvascular adaptations during placentation in pregnancy has been well established for decades. Inadequate dilatation of spiral arteries is associated with gestational complications, such as preeclampsia and/or intrauterine growth restriction. More recently, it has become clear that trophoblast cells invade and adapt decidual veins and lymphatic vessels 1 month before spiral arteries become patent and before intervillous space perfusion starts. Normal intervillous space hemodynamics is characterized by high volume flow at low velocity and pressure in the interseptal compartments surrounding the chorionic villi, hereby facilitating efficient maternal-fetal exchange. In case of shallow decidual vein dilatation, intervillous arterial supply exceeds venous drainage. This will cause congestion in the interseptal compartments with subsequently reduced perfusion and increased pressure. An efficient mechanism to counteract venous congestion and safeguard the viability of the conceptus is by reducing arterial inflow via shallow dilatation of the spiral arteries. This review made the case for intervillous space congestion as an unexplored trigger for inadequate spiral artery dilatation during the placentation process, eventually leading to abnormal systemic circulatory dysfunctions. An abnormal maternal venous function can result from an abnormal maternal immune response to paternal antigens with an imbalanced release of vasoactive mediators or can exist before conception. To get the full picture of abnormal placentation, maternal veins must not be forgotten.

Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction

This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.

Preconceptional evaluation of women with recurrent pregnancy loss: the additional value of assessing vascular and metabolic status

Background

A majority of recurrent pregnancy loss cases (RPL) remains unexplained. We hypothesized that complications in vascular and metabolic status may guide towards underlying problems that also predispose to RPL and that the number of pregnancy losses is related.

Methods

A retrospective study in 123 women with either a history of low-order RPL (2–3 pregnancy losses) or high-order RPL (≥ 4 pregnancy losses) and 20 women with a history of uncomplicated pregnancy (controls) was performed. Vascular status was assessed by measuring hemodynamic parameters, determining abnormal parameters and analyzing their contribution to the circulatory risk profile (CRP). In a similar way, metabolic status was assessed. Metabolic parameters were measured, used to determine abnormal parameters and analyzed for their contribution to the metabolic syndrome (MetS).

Results

No major differences were observed in vascular or metabolic parameters between women with RPL and controls. There was no relation with the number of pregnancy losses. However, when analyzing the presence of abnormal constituents, more than 80% of women with RPL had at least one abnormal constituent of the CRP. While only 27% had one or more abnormal constituent of the MetS.

Conclusions

The presence of abnormal circulatory factors prior to pregnancy, and to lesser extent constituents of the metabolic syndrome, may predispose to RPL and offer new insights to its pathophysiology.

Maternal haemodynamic function differs in pre-eclampsia when it is associated with a small-for-gestational-age newborn: a prospective cohort study

OBJECTIVE

To describe maternal haemodynamic differences in gestational hypertension with small-for-gestational-age babies (HDP + SGA), gestational hypertension with appropriate-for-gestational-age babies (HDP-only) and control pregnancies.

DESIGN

Prospective cohort study.

SETTING

Tertiary Hospital, UK.

POPULATION

Women with gestational hypertension and healthy pregnant women.

METHODS

Maternal haemodynamic indices were measured using a non-invasive Ultrasound Cardiac Output Monitor (USCOM-1A^® ) and corrected for gestational age and maternal characteristics using device-specific reference ranges.

MAIN OUTCOME MEASURES

Maternal cardiac output, stroke volume, systemic vascular resistance.

RESULTS

We included 114 HDP + SGA, 202 HDP-only and 401 control pregnancies at 26-41 weeks of gestation. There was no significant difference in the mean arterial blood pressure (110 versus 107 mmHg, P = 0.445) between the two HDP groups at presentation. Pregnancies complicated by HDP + SGA had significantly lower median heart rate (76 versus 85 bpm versus 83 bpm), lower cardiac output (0.85 versus 0.98 versus 0.97 MoM) and higher systemic vascular resistance (1.4 versus 1.0 versus 1.2 MoM) compared with control and HDP-only pregnancies, respectively (all P < 0.05).

CONCLUSION

Women with HDP + SGA present with more severe haemodynamic dysfunction than HDP-only. Even HDP-only pregnancies exhibit impaired haemodynamic indices compared with normal pregnancies, supporting a role of the maternal cardiovascular system in gestational hypertension irrespective of fetal size. Central haemodynamic changes may play a role in the pathogenesis of pre-eclampsia and should be considered alongside placental aetiology.

TWEETABLE ABSTRACT

Hypertensive disorders of pregnancy are associated with worse maternal haemodynamic function when associated with small-for-gestational-age birth.

Endothelial dysfunction and vascular stiffness in women with previous pregnancy complicated by early or late pre-eclampsia

OBJECTIVES

Pre-eclampsia (PE) is associated with an increased cardiovascular risk later in life. The persistence of endothelial dysfunction after delivery may represent the link between PE and cardiovascular disease. We aimed to evaluate endothelial function and arterial stiffness after delivery of pregnancy complicated by early-onset (EO) or late-onset (LO) PE and their correlation with gestational age and mean uterine artery pulsatility index at PE diagnosis and birth-weight percentile.

METHODS

The study included 30 women with previous EO-PE, 30 with previous LO-PE and 30 controls with no previous PE. Participants were examined at between 6 months and 4 years after delivery. All included women were free from cardiovascular risk factors and drugs. Data on demographic and clinical characteristics during pregnancy were collected retrospectively from obstetrical charts. Endothelial function and arterial stiffness were assessed by peripheral arterial tonometry and pulse-wave analysis.

RESULTS

All vascular parameters were significantly different, indicating circulatory impairment, in women with previous EO-PE. Women with previous LO-PE had higher vascular rigidity than did controls and all had normal values of reactive hyperemia index, although they were significantly lower when compared with those of controls. On multivariate analysis, gestational age and mean uterine artery pulsatility index at the time of PE diagnosis, and birth-weight percentile were all statistically related to the vascular indices studied, after correcting for confounding parameters.

CONCLUSIONS

Women with previous pregnancy complicated by PE, in particular those with early-onset disease, showed persistent microcirculatory dysfunction, as suggested by a significant reduction in reactive hyperemia index value, and increased arterial stiffness. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Cardiovascular and thrombogenic risk of decidual vasculopathy in preeclampsia

OBJECTIVE

Women with a history of preeclampsia (PE) have an increased prevalence of cardiometabolic, cardiovascular, and prothrombotic risk factors. Remotely, these women are at increased risk of developing cardiovascular and thrombotic disease. Decidual vasculopathy (DV) describes vascular lesions in the maternal spiral arteries of the uterus, which are found in approximately 40-60% of women with PE. DV is thought to be related to atherosclerosis because of their morphological similarity. The aim of this study was to investigate the association of cardiovascular and thrombogenic risk factors with DV in women with a history of PE.

STUDY DESIGN

We retrospectively analyzed the cardiovascular and thrombogenic risk of women with a history of PE, comparing cases with DV (n = 95) with cases without the lesions (n = 81) 7 months after the index pregnancy. Data from a cohort of patients with a history of PE were matched with records from our pathology database.

RESULTS

The DV group showed higher diastolic blood pressure (73 vs 70 mm Hg, P = .031), lower left ventricular stroke volume (71 vs 76 mL, P = .032), higher total peripheral vascular resistance (1546 vs 1385, P = .009), and a higher percentage of low plasma volume (34% vs 19%, P = .030). DV did not relate to other cardiovascular parameters, urinary protein, body mass index, lipid or glucose metabolism parameters, or thrombophilia.

CONCLUSION

In this study, in women with a history of PE, cases with DV had increased cardiovascular risk, exhibiting circulatory alterations, suggesting reduced venous reserves and elevated arterial tone, without metabolic or thrombophilic disturbances.

Patterns of maternal vascular remodeling and responsiveness in early- versus late-onset preeclampsia

OBJECTIVE

We sought to assess vascular structure and function in early- and late-onset preeclampsia (PE) at the time of diagnosis.

STUDY DESIGN

We evaluated 100 PE cases subdivided into 50 early- and 50 late-onset cases according to gestational age at onset (</>34 weeks), and 100 controls paired by maternal age and gestational age at scan with cases. Carotid intima-media thickness (IMT), distensibility, and circumferential wall stress together with inferior vena cava (IVC) collapsibility were assessed by ultrasound.

RESULTS

Early PE was characterized by increased carotid IMT diameters, and arterial stiffness with no significant changes in IVC parameters as compared to normotensive pregnancies. Late PE was characterized by significantly increased carotid IMT and lumen diameters as compared to controls while arterial stiffness, as expressed by distensibility, did not provide pronounced changes. A significant decrease of IVC collapsibility index was also observed in late PE as compared to controls.

CONCLUSION

The current data suggest that distinct vascular adaptations in early and late PE could reflect different pathophysiologic mechanisms. Future studies are warranted to further assess the complex etiologies and clinical expressions of the 2 entities.

The association between preeclampsia and arterial stiffness

A systematic review and meta-analysis was conducted using MEDLINE, EMBASE, and the Cochrane Library to investigate the association between preeclampsia and arterial stiffness. Twenty-three relevant studies were included. A significant increase in all arterial stiffness indices combined was observed in women with preeclampsia vs. women with normotensive pregnancies [standardized mean difference 1.62, 95% confidence interval (CI) 0.73-2.50]; carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx) were also significantly increased (weighted mean difference, WMDcfPWV 1.04, 95% CI 0.34-1.74; WMDAIx 15.10, 95% CI 5.08-25.11), whereas carotid-radial PWV (crPWV) increase did not reach significance (WMDcrPWV 0.99, 95% CI -0.07 to 2.05). Significant increases in arterial stiffness measurements were noted in women with preeclampsia compared with those with gestational hypertension. Arterial stiffness measurements may also be useful in predicting preeclampsia and may play a role in the increased risk of future cardiovascular complications seen in women with a history of preeclampsia.

Serial hemodynamic measurement in normal pregnancy, preeclampsia, and intrauterine growth restriction

OBJECTIVE

The study hypothesis was that hemodynamic measurements in conjunction with uterine artery Doppler could enable selection of women at risk for the development of preeclampsia or fetal growth restriction.

STUDY DESIGN

Systolic (SBP) and diastolic blood pressure, heart rate (RR), cardiac output (CO), total peripheral resistance (TPR), phase difference of SBP and RR interval were measured serially before, during, and after pregnancy. At 20 weeks, uterine artery Doppler measurement was performed. Outcome was classified as preeclampsia (PE) or gestational hypertension (GH) with or without fetal growth restriction (FGR), FGR without PE or GH, and normal pregnancy (NP). Differences between these groups were assessed by 1-way analysis of variance and discriminant analysis.

RESULTS

In early pregnancy, in comparison with NP (n = 28), PE/GH had a higher SBP and phase difference of SBP-RR interval. CO was higher in PE/GH without FGR (n = 5) but not PE/GH with FGR (n = 5). FGR, either with or without PE/GH (n = 4), was associated with higher TPR. Conjunction with uterine Doppler allowed selection of 93% of women with an abnormal outcome with a specificity of 100%.

CONCLUSION

The study supports our hypothesis that in early pregnancy, hemodynamic parameters differ from normal in women predisposed to develop preeclampsia or fetal growth restriction.

Subclinical signs of vascular damage relate to enhanced platelet responsiveness among nonpregnant formerly preeclamptic women

OBJECTIVE

In nonpregnant formerly preeclamptic women, the prevalence of occult cardiovascular abnormalities is increased. These high-risk women mildly benefit from low-dose aspirin in the prevention of recurrent disease. How this effect is mediated, either by affecting platelet or vascular function, is still unsettled. In this study, we tested the hypothesis that in these nonpregnant women, enhanced platelet responsiveness is common and related to microvascular damage.

STUDY DESIGN

At least 6 months' postpartum we evaluated in 66 formerly preeclamptic women platelet count, volume, and in vitro response to low-dose ADP (0.5 microg/mL). Peripheral levels of fibronectin (microg/mL), von Willebrand factor antigen (%), C-reactive protein (high-sensitive CRP, mg/L), urinary albumin, and protein (24-hour collection, g/mol creatinine) served as markers of vascular damage. Hemodynamic function was determined by plasma volume (iodine I 125 HSA indicator dilution method, mL/kg lean body mass), cardiac index (Doppler, mL/min/m2), blood pressure and heart rate (Dinamap [Critikon, Tampa, FL], mm Hg and beats/min, respectively). Thereafter, we subdivided these 66 women into 2 subgroups either with (n = 10, 15%) or without increased platelet responsiveness (n = 56, 85%). Both groups were compared nonparametrically.

RESULTS

Groups were comparable with respect to age, blood pressure, body mass index, parity, plasma volume, and cardiac index. Women with enhanced platelet responsiveness had higher levels of circulation fibronectin and CRP, and displayed more often albuminuria and proteinuria. In addition, even though platelet count was comparable between groups, the mean platelet volume was higher among women with enhanced platelet responsiveness.

CONCLUSION

Fifteen percent of formerly preeclamptic women had enhanced platelet responsiveness, which was associated with elevated levels of various markers for (micro) vascular damage. We speculate that in these women platelets are presensitized on a relatively dysfunctional endothelium. Although this association does not prove causality, these results may indicate a subgroup of women who benefit from low-dose aspirin in the prevention of recurrent disease in a next pregnancy.