Body fluid volume homeostasis is abnormal in pregnancies complicated with hypertension and/or poor 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.

Maternal hemodynamics assessment: Key to unlocking ignored functionalities of the female circulation

This chapter focuses on currently underappreciated aspects of the maternal circulation: blood pressure phenotypes, venous hemodynamics, intra-abdominal pressure, and body water homeostasis. Based on the hemodynamic balance between cardiac output and total peripheral resistance, flow-dominant and resistance-dominant phenotypes of normotension and hypertension exist, with different impacts on gestational outcome. Cardiac diastolic function and venous hemodynamics play a prominent role in gestational changes in cardiac output. An increase in intra-abdominal pressure during pregnancy interferes with body water volume homeostasis, similar to syndromes of multi-organ dysfunctions in non-pregnant individuals. Today, non-invasive maternal hemodynamics assessment allows for obtaining important information on these ignored circulatory functions in addition to conventional sphygmomanometric blood pressure measurement. This offers perspectives to improve current strategies for screening, diagnosis, and management of gestational hypertension disorders, a path, however, to be paved first by intensified multifaceted and multidisciplinary research.

Impaired maternal central hemodynamics precede the onset of vascular disorders of pregnancy at high altitude

Hypertensive disorders of pregnancy represent an escalating global health concern with increasing incidence in low- to middle-income countries and high-income countries alike. The current lack of methods to detect the subclinical stages of preeclampsia (PE) and fetal growth restriction (FGR), two common vascular disorders of pregnancy, limits treatment options to minimize acute- and long-term adverse outcomes for both mother and child. To determine whether impaired maternal cardiovascular or uteroplacental vascular function precedes the onset of PE and/or FGR (PE-FGR), we used noninvasive techniques to obtain serial measurements of maternal cardiac output (CO), stroke volume (SV), systemic vascular resistance (SVR), and uterine and fetal arterial resistance at gestational weeks 10-16, 20-24, and 30-34 for 79 maternal-infant pairs in La Paz-El Alto, Bolivia (3,850 m), where the chronic hypoxia of high altitude increases the incidence of PE and FGR. Compared with controls (n = 55), PE-FGR cases (n = 24) had lower SV, higher SVR, and greater uterine artery resistance at 10-16 wk. In addition, fetuses of women with lower SV and higher SVR at 10-16 wk showed evidence of brain sparing at 30-34 wk and had lower birth weights, respectively. Although the trajectory of SV and SVR across pregnancy was similar between groups, PE-FGR cases had a comparatively blunted rise in CO from the first to the third visit. Impaired maternal central hemodynamics and increased uteroplacental resistance precede PE-FGR onset, highlighting the potential use of such measures for identifying high-risk pregnancies at high altitudes.NEW & NOTEWORTHY In this prospective study of maternal central hemodynamics at high altitude, pregnancies later affected by preeclampsia (PE) and/or fetal growth restriction (FGR) show elevated systemic and uterine vascular resistance and reduced stroke volume as early as 10-16 wk gestation. Maternal hemodynamic assessments could facilitate early detection of high-risk pregnancies, improving resource allocation and reducing adverse outcomes. We propose an integrated model linking maternal cardiovascular performance to placental insufficiency, enhancing the understanding of PE-FGR in high-altitude settings.

Effect of Third Interstitial Fluid on Adverse Outcomes in Patients with Severe Pre-eclampsia and Twin Pregnancy: A 5-year Single-center Retrospective Study

OBJECTIVE

This study aims to identify the effect of third interstitial fluid on adverse outcomes in twin pregnancies with severe pre-eclampsia, and explore the differences in bad ending between twins and singletons.

METHODS

The present retrospective cohort study was conducted on patients with severe pre-eclampsia, who delivered in Tongji Hospital, Wuhan, China, between 2017 and 2022. The adverse outcomes in singleton and twin pregnancies with severe pre-eclampsia were initially investigated. Then, the diverse maternal and fetal consequences between singleton and twin pregnancies in patients with severe pre-eclampsia were compared after merging with the third interstitial fluid.

RESULTS

A total of 709 patients were included for the present study. Among these patients, 68 patients had twin pregnancies, and 641 patients had singleton pregnancies. The rate of postpartum hemorrhage (2.81% vs. 13.24%, P<0.001), and admission rate to the Neonatal Intensive Care Unit (NICU) after birth (30.73% vs. 63.24%, P=0.011) were significantly higher in twin pregnancies. The neonatal weight of twins was statistically lower than singletons (1964.73±510.61 g vs. 2142.92±731.25 g, P=0.008). For the groups with the third interstitial fluid, the delivery week (P=0.001) and rate of admission to the NICU after birth were significantly advanced in twin pregnancy group, when compared to singleton pregnancy group (P=0.032), and the length of hospital stay was shorter (P=0.044). Furthermore, there was no statistically significant difference between the twin pregnancy group and the singletony pregnancy group without the third interstitial fluid.

CONCLUSION

The maternal and fetal adverse outcomes of patients with severe pre-eclampsia increased in twin pregnancies, when compared to singleton pregnancies. Thus, when patients develop the third interstitial fluid, twin pregnancies would more likely lead to adverse fetal outcomes, when compared to singleton pregnancies, and there would be no significant difference in maternal adverse outcomes. More attention should be given to patients who merge with the third interstitial fluid.

Incidence and Risk Factors for Pregnancy-Related de Quervain's Tenosynovitis in South Korea: A Population-Based Epidemiologic Study

Background

Although pregnant or lactating women have been recognized to be predisposed to de Quervain's tenosynovitis (DQT), there is a lack of epidemiologic evidence. The purpose of this study was to estimate the nationwide incidence of pregnancy-related DQT (PRDQT) and to analyze risk factors using the Korean National Health Insurance (NHI) database.

Methods

A retrospective epidemiologic study of pregnant women in South Korea from 2013 to 2017 was conducted using the NHI claims database. Using corresponding diagnostic codes, we identified women diagnosed with DQT during pregnancy or the postpartum period. We calculated the cumulative incidence and analyzed risk factors such as demographics, pregnancy type, delivery method, gestational complications, and comorbidities using multivariate logistic regression analysis.

Results

Between 2013 and 2017, 34,342 patients with PRDQT were identified among 1,601,501 pregnant women, representing a cumulative incidence of approximately 2.1%. Age ≥ 30 years, multiple gestation, cesarean delivery, hypertensive disorders in pregnancy, and underlying rheumatoid arthritis were all identified as significant risk factors for the occurrence of PRDQT, whereas diabetic disorders in pregnancy and underlying diabetes mellitus were not.

Conclusions

In South Korea, PRDQT was found to affect approximately 2.1 out of 100 pregnant women between 2013 and 2017. The incidence and risk factors identified in this study can be used for clinical consultations and prediction, as well as for development of national health policies.

Nursing Diagnoses and Interventions in Women with Hypertensive Disorders of Pregnancy: A Scoping Review

Objective: To map the diverse scientific evidence on nursing diagnoses and interventions in women with pregnancy hypertensive disorders under Primary Health Care. Materials and method: A scoping review was conducted through nine stages in seven databases and the thesis and dissertation catalog of the Coordinating Office for Improving Higher Education Personnel. The search was performed from January to March 2021. Results: A total of 2,505 articles were retrieved, of which five were included in the final review. Nine primary diagnoses from the 2009-2011 version of NANDA-I were identified. Each diagnosis was classified according to physical, psychological, behavioral, and environmental characteristics. The interventions were related to controlling pain, anxiety, hemodynamic dysfunctions, self-esteem level, fluid replacement, patient/environment hygiene, and sleep-rest ratio. Conclusions: The nursing diagnoses and interventions presented in this study corroborate the clinical practice and aid nursing professionals’ reasoning.

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.

Hemodynamic pathways of gestational hypertension and preeclampsia

Gestational hypertension and preeclampsia are the 2 main types of hypertensive disorders in pregnancy. Noninvasive maternal cardiovascular function assessment, which helps obtain information from all the components of circulation, has shown that venous hemodynamic dysfunction is a feature of preeclampsia but not of gestational hypertension. Venous congestion is a known cause of organ dysfunction, but its potential role in the pathophysiology of preeclampsia is currently poorly investigated. Body water volume expansion occurs in both gestational hypertension and preeclampsia, and this is associated with the common feature of new-onset hypertension after 20 weeks of gestation. Blood pressure, by definition, is the product of intravascular volume load and vascular resistance (Ohm's law). Fundamentally, hypertension may present as a spectrum of cardiovascular states varying between 2 extremes: one with a predominance of raised cardiac output and the other with a predominance of increased total peripheral resistance. In clinical practice, however, this bipolar nature of hypertension is rarely considered, despite the important implications for screening, prevention, management, and monitoring of disease. This review summarizes the evidence of type-specific hemodynamic profiles in the latent and clinical stages of hypertensive disorders in pregnancy. Gestational volume expansion superimposed on an early gestational closed circulatory circuit in a pressure- or volume-overloaded condition predisposes a patient to the gradual deterioration of overall circulatory function, finally presenting as gestational hypertension or preeclampsia-the latter when venous dysfunction is involved. The eventual phenotype of hypertensive disorder is already predictable from early gestation onward, on the condition of including information from all the major components of circulation into the maternal cardiovascular assessment: the heart, central and peripheral arteries, conductive and capacitance veins, and body water content. The relevance of this approach, outlined in this review, openly invites for more in-depth research into the fundamental hemodynamics of gestational hypertensive disorders, not only from the perspective of the physiologist or the scientist, but also in assistance of clinicians toward understanding and managing effectively these severe complications of pregnancy.

Preeclampsia has two phenotypes which require different treatment strategies

The opinion on the mechanisms underlying the pathogenesis of preeclampsia still divides scientists and clinicians. This common complication of pregnancy has long been viewed as a disorder linked primarily to placental dysfunction, which is caused by abnormal trophoblast invasion, however, evidence from the previous two decades has triggered and supported a major shift in viewing preeclampsia as a condition that is caused by inherent maternal cardiovascular dysfunction, perhaps entirely independent of the placenta. In fact, abnormalities in the arterial and cardiac functions are evident from the early subclinical stages of preeclampsia and even before conception. Moving away from simply observing the peripheral blood pressure changes, studies on the central hemodynamics reveal two different mechanisms of cardiovascular dysfunction thought to be reflective of the early-onset and late-onset phenotypes of preeclampsia. More recent evidence identified that the underlying cardiovascular dysfunction in these phenotypes can be categorized according to the presence of coexisting fetal growth restriction instead of according to the gestational period at onset, the former being far more common at early gestational ages. The purpose of this review is to summarize the hemodynamic research observations for the two phenotypes of preeclampsia. We delineate the physiological hemodynamic changes that occur in normal pregnancy and those that are observed with the pathologic processes associated with preeclampsia. From this, we propose how the two phenotypes of preeclampsia could be managed to mitigate or redress the hemodynamic dysfunction, and we consider the implications for future research based on the current evidence. Maternal hemodynamic modifications throughout pregnancy can be recorded with simple-to-use, noninvasive devices in obstetrical settings, which require only basic training. This review includes a brief overview of the methodologies and techniques used to study hemodynamics and arterial function, specifically the noninvasive techniques that have been utilized in preeclampsia research.

Good performance of bioimpedance in early pregnancy to predict preeclampsia

INTRODUCTION

Preeclampsia (PE) affects 2-8% of pregnancies and is one of the main causes of maternal morbidity and mortality worldwide. Early identification of pregnant women at higher risk for PE would allow the use of interventions to reduce adverse maternal and perinatal outcomes.

OBJECTIVE

To assess the ability of bioelectrical impedance analysis (BIA) in pregnancy to predict the development of PE.

METHODS

This prospective cohort involved healthy nulliparas who underwent BIA at 17-20 weekś gestation and were followed until delivery. We used univariate and multivariate logistic regression to assess the ability of BIA measures to predict the occurrence of PE. We used an adjusted regression model to estimate the probability of developing PE, the Hosmer-Lemeshow test to assess the adequacy of the final model, and ROC curves to assess the sensitivity and specificity of different BIA measures in the prediction of PE.

RESULTS

Twelve (6.1%) of the 196 participants developed PE. In the final multivariate model, the following BIA measures were associated with the occurrence of PE: extracellular water/intracellular water ≤ 0.618, skeletal muscle mass ≥ 25 Kg, and body fat percentage ≥ 44%. The combination of these three measures had a predictive accuracy of 83.7%, a sensitivity of 83.3%, a specificity of 83.7%, and a negative predictive value of 98.7% for PE.

CONCLUSION

BIA done on nulliparous women at 17-20 weekś gestation has a good accuracy and high negative predictive value for the risk of developing PE.

Preeclampsia Is a Syndrome with a Cascade of Pathophysiologic Events

This review integrates the currently available information on the molecular, cellular, and systemic mechanisms involved in the pathophysiology of preeclampsia. It highlights that the growth, protection, and promotion of the conceptus requires the modulation of an intact maternal immune system, communication between the mother and fetus, and adaptation of the maternal organic functions. A malfunction in any of these factors, on either side, will result in a failure of the cascade of events required for the normal course of pregnancy. Maladaptive processes, initially aiming to protect the conceptus, fail to anticipate the gradually increasing cardiovascular volume load during the course of pregnancy. As a result, multiple organ dysfunctions install progressively and eventually reach a state where mother and/or fetus are at risk of severe morbidity or even mortality, and where the termination of pregnancy becomes the least harmful solution. The helicopter view on pathophysiologic processes associated with preeclampsia, as presented in this paper, illustrates that the etiology of preeclampsia cannot be reduced to one single mechanism, but is to be considered a cascade of consecutive events, fundamentally not unique to pregnancy.

Comparison of bioelectrical impedance analysis in healthy pregnant women and patient on hemodialysis

Pregnant woman undergoing dialysis face challenges such as miscarriage and stillbirth when carrying a baby to term. A complication of prenatal care is the difficulty in properly managing body fluids. We compare fluid volumes between healthy pregnant women and two pregnant women undergoing dialysis using bioelectrical impedance analysis (BIA). Data of 52 healthy pregnant women at various stages of their pregnancy were analyzed for the study. We included these many cases so as to collect sufficient data to compare them with our two cases of women undergoing dialysis who successfully completed their term deliveries. Fluid volumes were measured every week before and after dialysis using BIA. We also measured the levels of human atrial natriuretic peptide after dialysis. During dialysis, the dry weight (DW) of pregnant patients is altered based on the state of the amniotic fluid and fetus. However, evaluating body fluid and DW using radiography is difficult in pregnant women. BIA offers a mostly harmless alternative for such measurements. Using BIA, we were able to easily measure body fluid volume and change the setting of DW for dialysis. Thus, our successful example can serve as a reference for future cases of pregnant women undergoing dialysis. Nevertheless, given that the state of the fetus and amniotic fluid affect the results of dialysis, it is important that we use not only BIA but also a comprehensive evaluation to determine dialysis settings in pregnant women.

H,K-ATPase type 2 regulates gestational extracellular compartment expansion and blood pressure in mice

The modifications of the hemodynamic system and hydromineral metabolism are physiological features characterizing a normal gestation. Thus, the ability to expand plasma volume without increasing the level of blood pressure is necessary for the correct perfusion of the placenta. The kidney is essential in this adaptation by reabsorbing avidly sodium and fluid. In this study, we observed that the H,K-ATPase type 2 (HKA2), an ion pump expressed in kidney and colon and already involved in the control of the K⁺ balance during gestation, is also required for the correct plasma volume expansion and to maintain normal blood pressure. Indeed, compared with WT pregnant mice that exhibit a 1.6-fold increase of their plasma volume, pregnant HKA2-null mice (HKA2KO) only modestly expand their extracellular volume (×1.2). The renal expression of the epithelial Na channel (ENaC) α- and γ-subunits and that of the pendrin are stimulated in gravid WT mice, whereas the Na/Cl^- cotransporter (NCC) expression is downregulated. These modifications are all blunted in HKA2KO mice. This impeded renal adaptation to gestation is accompanied by the development of hypotension in the pregnant HKA2KO mice. Altogether, our results showed that the absence of the HKA2 during gestation leads to an "underfilled" situation and has established this transporter as a key player of the renal control of salt and potassium metabolism during gestation.

Preeclampsia: a gestational cardiorenal syndrome

It is generally accepted today that there are two different types of preeclampsia: an early-onset or placental type and a late-onset or maternal type. In the latent phase, the first one presents with a low output/high resistance circulation eventually leading in the late second or early third trimester to an intense and acutely aggravating systemic disorder with an important impact on maternal and neonatal mortality and morbidity; the other type presents initially as a high volume/low resistance circulation, gradually evolving to a state of circulatory decompensation usually in the later stages of pregnancy, with a less severe impact on maternal and neonatal outcome. For both processes, numerous dysfunctions of the heart, kidneys, arteries, veins and interconnecting systems are reported, most of them presenting earlier and more severely in early- than in late-onset preeclampsia; however, some very specific dysfunctions exist for either type. Experimental, clinical and epidemiological observations before, during and after pregnancy are consistent with gestation-induced worsening of subclinical pre-existing chronic cardiovascular dysfunction in early-onset preeclampsia, and thus sharing the pathophysiology of cardiorenal syndrome type II, and with acute volume overload decompensation of the maternal circulation in late-onset preeclampsia, thus sharing the pathophysiology of cardiorenal syndrome type 1. Cardiorenal syndrome type V is consistent with the process of preeclampsia superimposed upon clinical cardiovascular and/or renal disease, alone or as part of a systemic disorder. This review focuses on the specific differences in haemodynamic dysfunctions between the two types of preeclampsia, with special emphasis on the interorgan interactions between heart and kidneys, introducing the theoretical concept that the pathophysiological processes of preeclampsia can be regarded as the gestational manifestations of cardiorenal syndromes.

Anthropometry, standing posture, and body center of mass changes up to 28 weeks postpartum in Caucasians in the United States

BACKGROUND

Anthropometric models are used when body center of mass motion is calculated for assessment of dynamic balance. It is currently unknown how body segments and posture change in the postpartum period. Therefore, this study was conducted to evaluate the longitudinal changes in anthropometry, center of mass, and standing posture postpartum.

METHODS

Seventeen pregnant women were tested at nine different times: 16-20 weeks and 36-40 weeks gestation, and then in 4-week intervals from childbirth to 28 weeks postpartum. Anthropometry was measured and then participants conducted a static standing and static laying trial. Force plate data and motion capture data were used in combination with anthropometry to calculate the masses of individual segments and the body center of mass. Change over time was determined through a linear mixed model analysis.

RESULTS

Anthropometric changes related to the abdomen or fluid retention during pregnancy immediately regress to early pregnancy levels following childbirth. However, other changes related to breast tissue and fat deposits persist postpartum. As such, masses of different segments affect an anthropometric model for center of mass calculation, and body center of mass changes in the lateral and anterior directions postpartum. Vertical body center of mass position was unaffected.

SIGNIFICANCE

Increased postpartum breast mass may be the cause of persistent lordotic curvature changes in the lumbar spine. There is potential that this affects postpartum back pain. Future research should explore how body center of mass changes postpartum for individuals that do not breast feed, and thus may not have significant breast mass postpartum.

Maternal Venous Hemodynamic Dysfunction in Proteinuric Gestational Hypertension: Evidence and Implications

This review summarizes current knowledge from experimental and clinical studies on renal function and venous hemodynamics in normal pregnancy, in gestational hypertension (GH) and in two types of preeclampsia: placental or early-onset preeclampsia (EPE) and maternal or late-onset (LPE) preeclampsia, presenting at <34 weeks and ≥34 weeks respectively. In addition, data from maternal venous Doppler studies are summarized, showing evidence for (1) the maternal circulation functioning closer to the upper limits of capacitance than in non-pregnant conditions, with intrinsic risks for volume overload, (2) abnormal venous Doppler measurements obtainable in preeclampsia, more pronounced in EPE than LPE, however not observed in GH, and (3) abnormal venous hemodynamic function installing gradually from first to third trimester within unique pathways of general circulatory deterioration in GH, EPE and LPE. These associations have important clinical implications in terms of screening, diagnosis, prevention and management of gestational hypertensive diseases. They invite for further hypothesis-driven research on the role of retrograde venous congestion in the etiology of preeclampsia-related organ dysfunctions and their absence in GH, and also challenge the generally accepted view of abnormal placentation as the primary cause of preeclampsia. The striking similarity between abnormal maternal venous Doppler flow patterns and those observed at the ductus venosus and other abdominal veins of the intra-uterine growth restricted fetus, also invites to explore the role of venous congestion in the intra-uterine programming of some adult diseases.