Plasma volume and blood pressure regulation in hypertensive pregnancy

Obstructive Sleep Apnea in Pregnancy: A Comprehensive Review of Maternal and Fetal Implications

Obstructive sleep apnea (OSA) is a prevalent yet underdiagnosed condition in pregnancy, associated with various maternal and fetal complications. This review synthesizes the current evidence on the epidemiology, pathophysiology, and neurological consequences of OSA in pregnancy, along with the potential management strategies. Articles were sourced from the PubMed, EMBASE, and Cochrane databases until 2023. Our comprehensive review highlights that the incidence of OSA increases during pregnancy due to physiological changes such as weight gain and hormonal fluctuations. OSA in pregnancy is linked with gestational hypertension, pre-eclampsia, gestational diabetes, and potential adverse fetal outcomes such as intrauterine growth restriction and preterm birth. Continuous positive airway pressure (CPAP) therapy remains the most effective management strategy for pregnant women with OSA. However, adherence to CPAP therapy is often suboptimal. This comprehensive review underscores the importance of the early recognition, timely diagnosis, and effective management of OSA in pregnancy to improve both maternal and fetal outcomes. Future research should focus on enhancing screening strategies and improving adherence to CPAP therapy in this population.

The perspective of hypertension and salt intake in Chinese population

Salt intake is too high nowadays. It has been widely recognized that there is a close relationship between hypertension (HTN) and dietary salt intake. Investigations reveal that long-term high salt intake, mainly sodium intake, induces a relevant increase in blood pressure in hypertensive and normotensive individuals. According to most scientific evidence, a diet with high salt intake in public increases cardiovascular risk, salted-related HTN, and other HTN-associated outcomes. Given the clinical importance, this review aims to present the prevalence of HTN and trends in salt intake in the Chinese population and will comprehensively discuss the risk factors, causes, and mechanisms of the association between salt intake and HTN. The review also highlights the education of Chinese people regarding salt intake and the cost-effectiveness of salt reduction from a global perspective. Finally, the review will emphasize the need to customize the unique Chinese practices to reduce salt intake and how awareness changes people's eating lifestyle and helps adopt diet salt reduction strategies.

Non-invasive continuous blood pressure monitoring using the ClearSight system for pregnant women at high risks of post-partum hemorrhage: comparison with invasive blood pressure monitoring during cesarean section

Objective

This study aimed to investigate the accuracy and precision of continuous, non-invasive blood pressure obtained using the ClearSight system by comparing it with invasive arterial blood pressure, and to assess the hemodynamic changes using the ClearSight system in patients undergoing cesarean section.

Methods

Arterial pressure was measured invasively with an intra-arterial catheter and non-invasively using the ClearSight system during cesarean section in patients with placenta previa or placenta accreta. Blood pressure measurements obtained using these two means were then compared.

Results

Total 1,277 blood pressure measurement pairs were collected from 21 patients. Under Bland-Altman analysis, the ClearSight system demonstrated an acceptable accuracy with a bias and standard deviation of 8.8±13.4 mmHg for systolic blood pressure, -6.3±7.1 mmHg for diastolic blood pressure, and -2.7±8.0 mmHg for median blood pressure. Cardiac index levels were significantly elevated during fetal delivery and 5 minutes after placental removal, and systemic vascular resistance index levels were significantly decreased during fetal delivery and 40 minutes after placental removal.

Conclusion

In patients undergoing cesarean section, the ClearSight system showed excellent accuracy and precision compared to that of the currently used invasive monitoring system.

Sustained Elevated Circulating Activin A Impairs Global Longitudinal Strain in Pregnant Rats: A Potential Mechanism for Preeclampsia-Related Cardiac Dysfunction

Mediators of cardiac injury in preeclampsia are not well understood. Preeclamptic women have decreased cardiac global longitudinal strain (GLS), a sensitive measure of systolic function that indicates fibrosis and tissue injury. GLS is worse in preeclampsia compared to gestational hypertension, despite comparable blood pressure, suggesting that placental factors may be involved. We previously showed that Activin A, a pro-fibrotic factor produced in excess by the placenta in preeclampsia, predicts impaired GLS postpartum. Here, we hypothesized that chronic excess levels of Activin A during pregnancy induces cardiac dysfunction. Rats were assigned to sham or activin A infusion (1.25–6 µg/day) on a gestational day (GD) 14 (n = 6–10/group). All animals underwent blood pressure measurement and comprehensive echocardiography followed by euthanasia and the collection of tissue samples on GD 19. Increased circulating activin A (sham: 0.59 ± 0.05 ng/mL, 6 µg/day: 2.8 ± 0.41 ng/mL, p < 0.01) was associated with impaired GLS (Sham: −22.1 ± 0.8%, 6 µg/day: −14.7 ± 1.14%, p < 0.01). Activin A infusion (6 µg/day) increased beta-myosin heavy chain expression in heart tissue, indicating cardiac injury. In summary, our findings indicate that increasing levels of activin A during pregnancy induces cardiac dysfunction and supports the concept that activin A may serve as a possible mediator of PE-induced cardiac dysfunction.

Postural tachycardia syndrome (POTS) and antiphospholipid syndrome (APS): What do we know so far?

As part of the non-criteria clinical manifestations, postural orthostatic tachycardia syndrome (POTS), a multisystem autonomic dysfunction, can co-exist with antiphospholipid syndrome (APS). Several pieces of evidence hint on the autoimmune basis of POTS, and its possible association with several autoimmune diseases, including APS. Indeed, the evidence exists in the etiologies, symptomatology, and treatment options. Although infections, viral ones in particular, stress, and pregnancy are etiologies to both POTS and APS, the exact pathophysiological connection is still to be studied taking into consideration the activity of cytokines in both diseases. Nevertheless, certain immunomodulatory treatments used for the catastrophic or obstetrical forms of APS, such as intravenous immunoglobulins (IVIG) and steroids, have been also used for the treatment of POTS resistant to classical treatments. Therefore, our review aims to highlight the association between POTS and APS, shedding light on the common etiologies explaining the pathophysiology of the two disorders, the diagnostic approach to POTS as a possible clinical criterion of APS, and the treatment of APS in the context of treating POTS.

Breastfeeding and women's interest in specific food tastes

To determine whether breastfeeding alters women's interest in eating foods of different taste categories, we surveyed women at their 6-week post-partum check-up, asking them to rate their interest in eating various foods. Regardless of whether women responded in English or Spanish, they indicated greatest interest in eating sweet-tasting foods and least interest in eating sour-tasting foods, independent of whether they were breastfeeding. In general, the interest in eating foods of all taste qualities foods was increased in women who were breastfeeding; however, interest in eating salty and sour foods was not altered by breastfeeding in Spanish respondants. It is noteworthy that interest in eating foods of specific taste categories correlated with ratings of hunger in women who were not breastfeeding, but not in women who were breastfeeding. Thus, although breastfeeding women had a greater interest in eating foods of all taste categories, their interest does not appear to be driven solely by hunger. Finally, independent of breastfeeding, the interest in eating specific foods within taste categories differed between English and Spanish respondants, with Spanish respondants reporting greater interest in eating both nuts and bananas compared to English respondants. Together, these findings represent an initial approach to assess the impact of breastfeeding on interest in eating different types of food, and of how reproductive status and cultural differences may interact to affect food preferences and thereby to alter food choices.

Responses of the renin-angiotensin-aldosterone system in pregnant chronic kidney disease patients with and without superimposed pre-eclampsia

Background

Women with chronic kidney disease (CKD) are at increased risk of superimposed pre-eclampsia (SPE). Accurate identification of SPE is challenging. We hypothesized that specific components of the renin-angiotensin-aldosterone system (RAAS) would discriminate between CKD and SPE. The aim of the study was to establish differences in circulating and intrarenal RAAS in women with CKD with and without SPE and compare these to normotensive controls (NCs) and women with pre-eclampsia (PE).

Methods

White European NC women (n = 20), women with PE (n = 9), normotensive CKD without SPE (n = 8) and with SPE (n = 11) were recruited in the third trimester. Plasma renin, plasma and urine total angiotensinogen (AGT) concentrations were quantified by enzyme-linked immunosorbent assay, urinary tetrahydroaldosterone (TH-aldo) concentration by gas chromatography-mass spectrometry and placental growth factor (PlGF) by immunoassay.

Results

Urinary TH-aldo:creatinine ratios were lower in women with PE or SPE compared with NC or women with CKD (P < 0.05 for all). The same group differences were observed for plasma active renin and PlGF concentrations (P < 0.05 for all). Urine total AGT was higher in women with PE compared with NC (P < 0.05) and urine TH-aldo:urine AGT was lower (P < 0.05). However, women with SPE had lower urinary AGT concentrations compared with women with PE (P < 0.05). No differences in plasma total AGT were observed between groups.

Conclusions

Women with SPE have a lower urinary TH-aldo:creatinine ratio, lower plasma active renin and lower PlGF concentrations than women with CKD, comparable to women with PE without pre-existing disease, suggestive of similar pathophysiology. These data suggest disruption of the RAAS pathway in SPE similar to PE. Exploration of the predictive value of RAAS components for adverse pregnancy events in women with CKD is required.

Fibrinolytic proteins of normal pregnancy and pre-eclamptic patients in North West Nigeria

BACKGROUND

The hypercoagulability of pregnancy is exaggerated in pre-eclamptic state because of endothelial activation with resultant production of some endothelial derived proteins that are said to be inhibitors of fibrinolysis. This study compares these proteins like tPA, PAI-1 and D-dimers in normal pregnant women and the pre-eclamptic women.

METHODOLOGY

This was a comparative cross-sectional study. Eighty-five pre-eclamptic women were recruited as subjects and eighty five age, trimester and parity matched normotensive pregnant women as controls. Levels of PT, aPTT, tPA, PAI-1, D-dimer protein were determined in blood samples of subjects and controls. Urinalysis was performed with dipstick method on their urine samples. Data generated was analysed using the IBM®SPSS 20.0 (2011) soft ware packages and the level of significance was a p-value <0.05.

RESULTS

The mean age of the respondents was 29.9±5.2 years. The median(25th-75th percentile) values of D-dimer, tPA, and PAI-1 of subjects were 730 (305.000-1560.000ng/ml), 0.11 (0.065-0,300ng/ml) and 3.65 (2.970-4,400ng/ml) respectively which were significantly higher than the corresponding values in the controls of 520 (24.000-1030.000ng/ml), 0.05 (0.040-0.090ng/ml and 2.650 (2.125-3.400ng/ml) respectively, p<0.05 each.

CONCLUSION

The abnormal levels of PAI-1, D-dimer and tPA imply that they contribute to the exaggerated hypercoagulabilty state in pre-eclampsia thus, measuring their levels can help in the management of the condition.

How Do Home and Clinic Blood Pressure Readings Compare in Pregnancy?

Hypertensive disorders during pregnancy result in substantial maternal morbidity and are a leading cause of maternal deaths worldwide. Self-monitoring of blood pressure (BP) might improve the detection and management of hypertensive disorders of pregnancy, but few data are available, including regarding appropriate thresholds. This systematic review and individual patient data analysis aimed to assess the current evidence on differences between clinic and self-monitored BP through pregnancy. MEDLINE and 10 other electronic databases were searched for articles published up to and including July 2016 using a strategy designed to capture all the literature on self-monitoring of BP during pregnancy. Investigators of included studies were contacted requesting individual patient data: self-monitored and clinic BP and demographic data. Twenty-one studies that utilized self-monitoring of BP during pregnancy were identified. Individual patient data from self-monitored and clinic readings were available from 7 plus 1 unpublished articles (8 studies; n=758) and 2 further studies published summary data. Analysis revealed a mean self-monitoring clinic difference of ≤1.2 mm Hg systolic BP throughout pregnancy although there was significant heterogeneity (difference in means, I2 >80% throughout pregnancy). Although the overall population difference was small, levels of white coat hypertension were high, particularly toward the end of pregnancy. The available literature includes no evidence of a systematic difference between self and clinic readings, suggesting that appropriate treatment and diagnostic thresholds for self-monitoring during pregnancy would be equivalent to standard clinic thresholds.

Pregnancy affects the pharmacokinetics of sildenafil and its metabolite in the rabbit

1. There is growing interest in the use of sildenafil during pregnancy for various maternal and fetal conditions. This study aims to investigate the effect of pregnancy on the maternal pharmacokinetics (PK) of sildenafil and its main metabolite desmethylsildenafil in rabbits. Using NONMEM, population PK modeling was performed based on plasma samples from 31 rabbits of whom 15 were pregnant and 16 were not. All received a single subcutaneous sildenafil dose of 10 mg/kg. One sample was obtained per rabbit at either 30, 60, 120, 360, 720 or 1320 min after sildenafil administration. 2. A two- and one-compartment PK-model best described the data for sildenafil and desmethylsildenafil, respectively. Compared to non-pregnant rabbits, the central and peripheral volume of distribution and inter-compartmental clearance of sildenafil were lower in pregnant rabbits [32.1 versus 12.2 L, 110 versus 44.4 L and 25.5 versus 12.1 L/h; all p < 0.05]. The formation clearance from sildenafil to desmethylsildenafil was also reduced during pregnancy [13.3 versus 7.8 L/h; p < 0.05]. 3. In contrast, the elimination clearance of desmethylsildenafil, was higher in pregnancy [73.5 versus 116. 9; p < 0.05]. In rabbits, pregnancy impacts PK parameters of sildenafil and its metabolite, leading to an increased peak concentration and 24 h exposure for sildenafil and a decreased 24 h exposure for desmethylsildenafil.

Recurrent pre-eclampsia in women with metabolic syndrome and low plasma volume: a retrospective cohort study

OBJECTIVE

To determine the prevalence of recurrent pre-eclampsia in women with a history of pre-eclampsia with both metabolic syndrome and low plasma volume postpartum, as compared with women without either entity.

DESIGN

Retrospective cohort study.

SETTING

Three tertiary referral hospitals in the Netherlands.

POPULATION

Women with a history of pre-eclampsia.

METHODS

In 196 women with a history of pre-eclampsia we determined the presence or absence of metabolic syndrome using the World Health Organization criteria and measured plasma volume with the (125) I-human serum albumin indicator dilution technique. We compared the prevalence of recurrent pre-eclampsia in four groups, classified according to presence or absence of metabolic syndrome and low or normal plasma volume, calculating odds ratios (OR), adjusted for confounders.

MAIN OUTCOME MEASURE

Recurrence of pre-eclampsia in the subsequent pregnancy.

RESULTS

The prevalence of recurrent pre-eclampsia was 12% (12/99) in women without metabolic syndrome with normal plasma volume, versus 47% (8/17) in women with both metabolic syndrome and low plasma volume: OR 6.44 (95% CI 2.09-19.90), adjusted OR 7.90 (95% CI 2.30-27.16). Recurrent pre-eclampsia was present in 44% (10/23) and 25% (14/57) of women with isolated metabolic syndrome and low plasma volume, respectively.

CONCLUSIONS

In the concomitant presence of metabolic syndrome and low plasma volume, the prevalence of recurrent pre-eclampsia was nearly 50%, which is four times as high as the prevalence in women without either entity.

TWEETABLE ABSTRACT

Metabolic syndrome and low plasma volume raise the risk of recurrent pre-eclampsia to nearly 50%.

Associations of anxiety disorders, depressive disorders and body weight with hypertension during pregnancy

The purpose of this study was to prospectively examine the relationships between maternal DSM-IV-TR anxiety disorders, depressive disorders, and body mass index (BMI) with arterial hypertension and blood pressure during pregnancy. In the Maternal Anxiety in Relation to Infant Development (MARI) study, N = 306 women were enrolled in early pregnancy and repeatedly assessed during peripartum period. DSM-IV-TR anxiety and depressive disorders prior to pregnancy, lifetime anxiety/depression liability, and BMI during early pregnancy were assessed with the Composite International Diagnostic Interview for Women (CIDI-V). Based on their prepregnancy status, all participants were assigned to one of the following initial diagnostic groups: no anxiety nor depressive disorder (no AD), pure depressive disorder (pure D), pure anxiety disorder (pure A), and comorbid anxiety and depressive disorder (comorbid AD). Blood pressure measurements were derived from medical records. Arterial hypertension during pregnancy was defined by at least two blood pressure values ≥140 mmHg systolic and/or ≥90 mmHg diastolic. N = 283 women with at least four documented blood pressure measurements during pregnancy were included in the analyses. In this sample, N = 47 women (16.6 %) were identified with arterial hypertension during pregnancy. Women with comorbid AD (reference group: no AD) had a significantly higher blood pressure after adjustment for age, parity, smoking, occupation, household income, and education (systolic: linear regression coefficient [β] = 3.0, 95 % confidence interval [CI] = 0.2-5.7; diastolic, β = 2.3, 95 % CI = 0.1-4.4). Anxiety liability was associated with an increased risk of hypertension (odds ratio [OR] = 1.1, 95 % CI = 1.0-1.3) and a higher systolic blood pressure (β = 0.4, 95 % CI = 0.0-0.7). The adjusted interaction model revealed a significant interaction between the diagnostic group pure A and BMI for hypertension (ORIT = 1.5, 95 % CI = 1.1-2.1). Especially, women with a lifetime history of comorbid anxiety and depression and obese pregnant women with a lifetime history of pure anxiety disorder should be informed about their heightened risk of hypertension, monitored with regular blood pressure measurements, and provided with strategies for prevention and early intervention such as changes in diet and physical activity.

Ultrasound-promoted one-pot five-components synthesis of biologically active novel bis((6-alkyl or phenyl-2-phenylpyrimidine-4-yl) oxy) alkane or methyl benzene derivatives

We have described a synthesis of novel five-component reaction (5-CR) of bis((6-alkyl or phenyl-2-phenylpyrimidine-4-yl) oxy) alkane or methyl benzene derivatives under ultrasound irradiation. A useful ultrasound effect was observed and title products were obtained with high yields after 25-40 min sonication. Structural confirmation and characterization of the products based on the analytical, chemical, and spectral analysis. The results show obviously, that to reach a high efficiency of ultrasonic systems in synthetic chemical processes. Our procedure compared to the conventional heating method has the benefit of higher reaction yields and shorter reaction times. The in vitro antibacterial tests show that some of the target compounds have promising activities. Structure-activity relationships (SAR) were established for the substitutions on the pyrimidine rings and related length of linear chain linker.

Vascular Response to Graded Angiotensin II Infusion in Offspring Subjected to High-Salt Drinking Water during Pregnancy: The Effect of Blood Pressure, Heart Rate, Urine Output, Endothelial Permeability, and Gender

Introduction. Rennin-angiotensin system and salt diet play important roles in blood pressure control. We hypothesized that the high-salt intake during pregnancy influences the degree of angiotensin-dependent control of the blood pressure in adult offspring. Methods. Female Wistar rats in two groups (A and B) were subjected to drink tap and salt water, respectively, during pregnancy. The offspring were divided into four groups as male and female offspring from group A (groups 1 and 2) and from group B (groups 3 and 4). In anesthetized matured offspring mean arterial pressure (MAP), heart rate and urine output were measured in response to angiotensin II (AngII) (0-1000 ng/kg/min, iv) infusion. Results. An increase in MAP was detected in mothers with salt drinking water (P < 0.05). The body weight increased and kidney weight decreased significantly in male offspring from group 3 in comparison to group 1 (P < 0.05). MAP and urine volume in response to AngII infusion increased in group 3 (P < 0.05). These findings were not observed in female rats. Conclusion. Salt overloading during pregnancy had long-term effects on kidney weight and increased sex-dependent response to AngII infusion in offspring (adult) that may reveal the important role of diet during pregnancy in AngII receptors.

Serum perfluorooctanoic acid and perfluorooctane sulfonate concentrations in relation to birth outcomes in the Mid-Ohio Valley, 2005-2010

BACKGROUND

Previous research suggests perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) may be associated with adverse pregnancy outcomes.

OBJECTIVE

We conducted a population-based study of PFOA and PFOS and birth outcomes from 2005 through 2010 in a Mid-Ohio Valley community exposed to high levels of PFOA through drinking-water contamination.

METHODS

Women provided serum for PFOA and PFOS measurement in 2005-2006 and reported reproductive histories in subsequent follow-up interviews. Reported singleton live births among 1,330 women after 1 January 2005 were linked to birth records (n = 1,630) to identify the outcomes of preterm birth (< 37 weeks gestation), pregnancy-induced hypertension, low birth weight (< 2,500 g), and birth weight (grams) among full-term infants.

RESULTS

We observed little or no evidence of association between maternal serum PFOA or PFOS and preterm birth (n = 158) or low birth weight (n = 88). Serum PFOA and PFOS were both positively associated with pregnancy-induced hypertension (n = 106), with adjusted odds ratios (ORs) per log unit increase in PFOA and PFOS of 1.27 (95% CI: 1.05, 1.55) and 1.47 (95% CI: 1.06, 2.04), respectively, but associations did not increase monotonically when categorized by quintiles. Results of subanalyses restricted to pregnancies conceived after blood collection were consistent with the main analyses. There was suggestion of a modest negative association between PFOS and birth weight in full-term infants (-29 g per log unit increase; 95% CI: -66, 7), which became stronger when restricted to births conceived after the blood sample collection (-49 g per log unit increase; 95% CI: -90, -8).

CONCLUSION

Results provide some evidence of positive associations between measured serum perfluorinated compounds and pregnancy-induced hypertension and a negative association between PFOS and birth weight among full-term infants.

Matrix metalloproteinases as drug targets in preeclampsia

Preeclampsia is an important syndrome complicating pregnancy. While the pathogenesis of preeclampsia is not entirely known, poor placental perfusion leading to widespread maternal endothelial dysfunction is accepted as a major mechanism. It has been suggested that altered placental expression of matrix metalloproteinases (MMPs) may cause shallow cytotrophoblastic invasion and incomplete remodeling of the spiral arteries. MMPs are also thought to link placental ischemia to the cardiovascular alterations of preeclampsia. In fact, MMPs may promote vasoconstriction and surface receptors cleavage affecting the vasculature. Therefore, the overall goal of this review article is to provide an overview of the pathophisiology of preeclampsia, more specifically regarding the role of MMPs in the pathogenesis of preeclampsia and the potential of MMP inhibitors as therapeutic options.

Normal pregnancy: mechanisms underlying the paradox of a ouabain-resistant state with elevated endogenous ouabain, suppressed arterial sodium calcium exchange, and low blood pressure

Endogenous cardiotonic steroids (CTS) raise blood pressure (BP) via vascular sodium calcium exchange (NCX1.3) and transient receptor-operated channels (TRPCs). Circulating CTS are superelevated in pregnancy-induced hypertension and preeclampsia. However, their significance in normal pregnancy, where BP is low, is paradoxical. Here we test the hypothesis that vascular resistance to endogenous ouabain (EO) develops in normal pregnancy and is mediated by reduced expression of NCX1.3 and TRPCs. We determined plasma and adrenal levels of EO and the impact of exogenous ouabain in pregnancy on arterial expression of Na(+) pumps, NCX1.3, TRPC3, and TRPC6 and BP. Pregnant (embryonic day 4) and nonpregnant rats received infusions of ouabain or vehicle. At 14-16 days, tissues and plasma were collected for blotting and EO assay by radioimmunoassay (RIA), liquid chromatography (LC)-RIA, and LC-multidimensional mass spectrometry (MS3). BP (-8 mmHg; P < 0.05) and NCX1.3 expression fell (aorta -60% and mesenteric artery -30%; P < 0.001) in pregnancy while TRPC expression was unchanged. Circulating EO increased (1.14 ± 0.13 nM) vs. nonpregnant (0.6 ± 0.08 nM; P < 0.05) and was confirmed by LC-MS3 and LC-RIA. LC-MS3 revealed two previously unknown isomers of EO; one increased ∼90-fold in pregnancy. Adrenal EO but not isomers were increased in pregnancy. In nonpregnant rats, similar infusions of ouabain raised BP (+24 ± 3 mmHg; P < 0.001). In ouabain-infused rats, impaired fetal and placental growth occurred with no BP increase. In summary, normal pregnancy is an ouabain-resistant state associated with low BP, elevated circulating levels of EO, two novel steroidal EO isomers, and increased adrenal mass and EO content. Ouabain raises BP only in nonpregnant animals. Vascular resistance to the chronic pressor activity of endogenous and exogenous ouabain is mediated by suppressed NCX1.3 and reduced sensitivity of events downstream of Ca(2+) entry. The mechanisms of EO resistance and the impaired fetal and placental growth due to elevated ouabain may be important in pregnancy-induced hypertension (PIH) and preeclampsia (PE).

Circulatory and renal consequences of pregnancy in diabetic NOD mice

OBJECTIVES

Women with diabetes have elevated gestational risks for severe hemodynamic complications, including preeclampsia in mid- to late pregnancy. This study employed continuous, chronic radiotelemetry to compare the hemodynamic patterns in non-obese diabetic (NOD) mice who were overtly diabetic or normoglycemic throughout gestation. We hypothesized that overtly diabetic, pregnant NOD mice would develop gestational hypertension and provide understanding of mechanisms in progression of this pathology.

STUDY DESIGN

Telemeter-implanted, age-matched NOD females with and without diabetes were assessed for six hemodynamic parameters (mean, systolic, diastolic, pulse pressures, heart rate and activity) prior to mating, over pregnancy and over a 72 h post-partum interval. Urinalysis, serum biochemistry and renal histopathology were also conducted.

RESULTS

Pregnant, normoglycemic NOD mice had a hemodynamic profile similar to other inbred strains, despite insulitis. This pattern was characterized by an interval of pre-implantation stability, post implantation decline in arterial pressure to mid gestation, and then a rebound to pre-pregnancy baseline during later gestation. Overtly diabetic NOD mice had a blood pressure profile that was normal until mid-gestation then become mildly hypotensive (-7 mmHg, P < 0.05), severely bradycardic (-80 bpm, P < 0.01) and showed signs of acute kidney injury. Pups born to diabetic dams were viable but growth restricted, despite their mothers' failing health, which did not rebound post-partum (-10% pre-pregnancy pressure and HR, P < 0.05).

CONCLUSIONS

Pregnancy accelerates circulatory and renal pathologies in overtly diabetic NOD mice and is characterized by depressed arterial pressure from mid-gestation and birth of growth-restricted offspring.

Role of dysfunctional maternal venous hemodynamics in the pathophysiology of pre-eclampsia: a review

The venous compartment has an important function in regulation and control of cardiac output. Abnormalities of cardiac output have been found in early gestational stages of both early- and late-onset pre-eclampsia. The venous compartment also maintains the balance between circulating and non-circulating blood volumes and regulates the amount of reserve blood stored in the splanchnic venous bed. It is well known that adaptive regulation of maternal blood volume is disturbed in pre-eclampsia. Abnormal venous hemodynamics and venous congestion are responsible for secondary dysfunction of several organs, such as the kidneys in cardiorenal syndrome and the liver in cardiac cirrhosis. Renal and liver dysfunctions are among the most relevant clinical features of pre-eclampsia. Doppler sonography studies have shown that the maternal venous compartment is subject to gestational adaptation, and that blood flow characteristics at the level of renal interlobar and hepatic veins are different in pre-eclampsia compared with uncomplicated pregnancy. In comparison to late-onset pre-eclampsia, in early-onset pre-eclampsia venous Doppler flow abnormalities are more prominent and present up to weeks before clinical symptoms. This paper reviews the growing evidence that dysfunction of maternal venous hemodynamics is part of the pathophysiology of pre-eclampsia and may perhaps be more important than is currently considered. Doppler sonography is a safe and easily performed method with which to study maternal venous hemodynamics. Therefore, exploring the role of maternal venous hemodynamics using Doppler sonography is an exciting new research topic for those who are interested in cardiovascular background mechanisms, as well as prediction and clinical work-up of pre-eclampsia.

Vascular Complications of Systemic Sclerosis during Pregnancy

Systemic sclerosis (SSc) is a chronic autoimmune disorder characterized by progressive fibrosis of the skin and visceral tissues as well as a noninflammatory vasculopathy. Vascular disease in systemic sclerosis is a major cause of morbidity and mortality among nonpregnant patients with SSc and is even a bigger concern in the pregnant SSc patient, as the underlying vasculopathy may prevent the required hemodynamic changes necessary to support a growing pregnancy. Vascular manifestations including scleroderma renal crisis and pulmonary arterial hypertension should be considered relative contraindications against pregnancy due to the high associations of both maternal and fetal morbidity and mortality. In contrast, Raynaud's phenomenon may actually improve somewhat during pregnancy. Women with SSc who are considering a pregnancy or discover they are pregnant require evaluation for the presence and extent of underlying vasculopathy. In the absence of significant visceral vasculopathy, most women with SSc can expect to have reasonable pregnancy outcomes.

Effect of pregnancy on postural tachycardia syndrome

OBJECTIVES

To compare the clinical presentation, autonomic dysfunction, and pregnancy outcomes in parous and nulliparous women with postural tachycardia syndrome (POTS) and in women with POTS before and after pregnancy.

PATIENTS AND METHODS

This study consists of women who had at least 1 pregnancy during which time they met criteria for POTS between May 1993 and July 2009. All patients underwent standard autonomic testing. POTS was defined as a heart rate (HR) increase of greater than 30 beats/min on head-up tilt (HUT) with symptoms of orthostatic intolerance. Patients' charts were reviewed retrospectively to determine pregnancy outcomes.

RESULTS

Clinical characteristics related to POTS did not differ between parous and nulliparous women except for disease duration (parous, 3.7+/-2.6; nulliparous, 2.1+/-2.2; P<.001). Autonomic dysfunction did not differ between groups (change in HR on HUT: parous, 42.6+/-12.0 beats/min; nulliparous, 41.3+/-10.6 beats/min; P=.39). Of 116 total pregnancies, adverse pregnancy outcomes were reported in 9% and maternal complications in 1%. No complication was related to POTS. There was a trend toward modest improvement in autonomic dysfunction before and after pregnancy (change in HR on HUT: before pregnancy, 38.1+/-22.7 beats/min; after pregnancy, 21.9+/-14.9 beats/min; P=.07).

CONCLUSION

The long-term impact of pregnancy on POTS does not appear to be clinically important. However, there does appear to be a trend toward improvement in the short-term postpartum period. Adverse pregnancy events were similar to those seen in the general public and do not present a barrier to women with POTS who want to have children.

Diagnosis and treatment of hypertensive disorders during pregnancy

Pregnancy is a cardiovascular and metabolic challenge to the human female body. This review summarizes current knowledge on the regulation of blood pressure and plasma volume in normal and hypertensive pregnant women. During pregnancy, systemic vascular resistance and blood pressure decrease, whereas cardiac output and blood volume increase to safeguard an adequate circulation in the utero-placental arterial bed. Hypertension affects 10% of all pregnancies and is accompanied by an increase in foetal and maternal morbidity and mortality. Hypertension in pregnancy includes a wide spectrum of conditions, including pre-eclampsia and eclampsia, pre-eclampsia superimposed on chronic hypertension, chronic hypertension, and gestational hypertension. Endothelial dysfunction, oxidative stress and an exaggerated inflammatory response are features related to hypertensive disorders. Microangiopathic disorders can easily mimic hypertensive disorders during pregnancy. Although they have some symptoms in common, they require another type of management. To reduce the risk of maternal and foetal complications due to haemodynamic maladaptations, the current management includes rest at home or in the hospital, close monitoring of maternal and foetal signs and symptoms, early start of antihypertensive therapy, and timely delivery regarding maternal and foetal survival chances. Thresholds to initiate blood pressure lowering treatment during pregnancy are 160 mmHg systole or 110 mmHg diastole. Below these thresholds, treatment must be individualized because current evidence does not support aggressive medical interventions. Alpha-methyldopa and dihydropyridinic calcium channel blockers are among the recommended antihypertensives.

Intracranial haemorrhage in pregnancy

Intracranial haemorrhage (ICH) is a rare, yet potentially devastating event in pregnancy. There is a risk of maternal mortality or morbidity and a significant risk to the unborn child. The risk of haemorrhage increases during the third trimester and is greatest during parturition and the puerperium. ICH can be extradural, subdural, subarachnoid or intraparenchymal. Causes of bleeding include trauma, arteriovenous malformations, aneurysms, preeclampsia/eclampsia and venous thrombosis. Urgent neurosurgical conditions generally outweigh obstetric considerations in management decisions, although anaesthetic and surgical modifications can be made to minimize adverse effects to the fetus.

Increased Sympathetic Activity Present in Early Hypertensive Pregnancy is Not Lowered by Plasma Volume Expansion

OBJECTIVE

To evaluate whether sympathetic activity is increased in early-onset hypertensive pregnancy and whether this can be influenced by management with plasma volume expansion.

METHODS

The study group consisted of 74 subjects, of which 37 had early-onset hypertensive disorders of pregnancy (preeclampsia or gestational hypertension with fetal growth restriction), who were included at 24 to 34 weeks in a randomized controlled trial of management with (n = 18) or without (n = 19) plasma volume expansion. Heart rate and blood pressure variabilities, LF/HF ratio for heart rate, baroreflex sensitivity, and phase difference at low frequency (LF approximately 0.1 Hz) were calculated by spectral analysis from continuous heart rate and blood pressure recordings of the finger pulse wave (Portaprestrade mark, TNO). Measurements were performed at inclusion, after 20 to 40 hours and after 65 to 100 hours. The control group consisted of 29 women with a normal pregnancy and 8 women who had late-onset preeclampsia after 34 weeks. Controls were measured at 32 weeks. All controls had a normal blood pressures at that time.

RESULTS

LF variability of heart rate and blood pressure were significantly higher and baroreflex sensitivity was significantly lower in early-onset patients compared with normal controls. A significant trend towards higher LF variability of blood pressure and lower baroreflex sensitivity was found from normal controls to late-onset controls to early-onset patients. Parameters of sympathetic activity were not influenced by plasma volume expansion.

CONCLUSION

Sympathetic activity was increased in early-onset hypertensive pregnancy. However, this was not affected by management with plasma volume expansion, suggesting that hypovolaemia in preeclampsia is a secondary phenomenon.

Dietary folate intake, use of folate supplements, lifestyle factors, and serum folate levels among pregnant women in Tokyo, Japan

AIM

The aim of this study was to determine the folate status of pregnant women and how it is affected by dietary folate, use of folate supplements, and lifestyle factors (smoking and drinking habits).

METHODS

This cross-sectional study involved 537 healthy, pregnant women attending an obstetric clinic in a Tokyo suburb. Morning blood samples were taken to determine serum folate levels. A brief, self-administered diet history questionnaire and another questionnaire were used to obtain information about food intake and demographic data. Logistic regression was used to identify factors associated with a normal serum folate level (> 6 ng/mL), taking women with a low serum folate level (< or = 6 ng/mL) as the reference group.

RESULTS

The median dietary folate intake was 207.2 microg/day; the median serum folate level was 3.9 ng/ml. A normal serum folate level was significantly associated with increased dietary folate intake (odds ratio = 1.003, P < 0.05), use of folate supplements (odds ratio = 8.152, P < 0.001), and more than four cups of green tea (odds ratio = 0.467, P < 0.05), but not with lifestyle factors in the adjusted analysis.

CONCLUSIONS

Most pregnant women (79.3%) in the present study had a low serum folate level, reflecting a low dietary intake of folate and a low proportion of women taking folate supplements. Supplement use had a much stronger association with a normal serum folate level than dietary folate intake. Since this study was not population-based, further studies are needed to confirm the results.

The effect of obesity on heart rate (heart period) and physiologic parameters during pregnancy

Obesity and excess gestational weight gain (EGWG) in pregnancy increase the risk for adverse maternal and infant outcomes. Along with careful monitoring of weight gain during pregnancy, early identification of a maladaptive response to the changes of pregnancy may help to avoid adverse outcomes. Simple physiologic markers such as resting heart rate (HR), heart period (HP), and blood pressure (BP) may be powerful predictors of cardiovascular adaptation to pregnancy. This article summarizes the current state of the science regarding the effect of obesity (body mass index [BMI] > or =30 kg/m(2)) and EGWG in pregnant women at rest in laboratory settings. The impact of differences in weight gain (kg and BMI) on pregnancy outcomes is also examined. A search was conducted for articles published from 1985 to 2006 reporting data on body weight and HR or HP at rest from randomized controlled trials or controlled trials conducted in laboratory settings involving pregnant women at low or high risk for adverse pregnancy outcomes who were obese or had EGWG. A meta-analysis was conducted on the 23 studies meeting inclusion criteria to explore the relation of BMI to HR, HP, and physiologic parameters. Autonomic responsiveness was found to be diminished in obese women with a BMI > 30 kg/m(2) and in women with high risk for adverse pregnancy outcomes, which may indicate a maladaptive autonomic response that is imbalanced and disorganized and that reduces adaptation to environmental demands.

Hemodynamic parameters during normal and hypertensive pregnancy in rats: evaluation of renal salt and water transporters

OBJECTIVE

To determine whether alterations in extracellular volume expansion observed during normal and hypertensive pregnancy run in parallel to changes in the mRNA expression of renal transporters.

METHODS

Wistar rats were divided into four groups: control (C, n = 5); pregnancy (P, n = 5); N(omega)-nitro-l-arginine methyl ester (L-NAME; 50 mg/kg/d)-treated control (H, n = 6); and pregnant rats (HP, n = 6). Hemodynamic studies were performed on day 14 of pregnancy, at which time we also analyzed of the sodium transporters (NHE3, Na/K/2Cl and Na/Cl), potassium channel (ROMK2) and water channel (AQP2).

RESULTS

As expected, P rats presented high cardiac output (CO) and normal blood pressure (BP), whereas H rats presented lower CO and elevated BP. A significant (threefold) increase in total vascular resistance and a decrease in stroke volume were observed in the HP group. Hypertension resulting from nitric oxide (NO) synthesis inhibition blunted systemic hemodynamic adaptations during pregnancy. Compared with C rats, mRNA expression of ROMK2 in P rats was lower, whereas that of AQP2 was higher. Expression of AQP2 was significantly higher in H than in C or HP groups. Expression of BSC and NHE3 was lower in the HP than in the P group. The NO inhibition also provoked renal transporter alterations in HP.

CONCLUSIONS

Our results suggest that tubule transporter variants may mediate the hemodynamic adaptations seen during pregnancy, although we cannot rule out the hypothesis that other factors are also mediating hemodynamic changes.

A prospective study of early-pregnancy plasma malondialdehyde concentration and risk of preeclampsia

OBJECTIVES

Preeclampsia is associated with elevated plasma malondialdehyde concentration, but prospective data are scarce. We examined the relation between early-pregnancy plasma malondialdehyde and subsequent preeclampsia risk.

DESIGN AND METHODS

In a nested case-control analysis, we measured malondialdehyde concentrations in 22 women who developed preeclampsia and 711 who remained normotensive during pregnancy. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI). We repeated analyses after adjustment for early-pregnancy plasma lipid concentrations, which are related to preeclampsia risk and lipid peroxidation measures.

RESULTS

After adjustment for confounders, preeclampsia risk increased across tertiles of malondialdehyde concentration (trend P = 0.04). Further adjustment for triglyceride concentration slightly strengthened the association. Middle- and high-tertile malondialdehyde ORs were 3.2 (CI 0.8-12.2) and 4.2 (1.1-16.0) versus low-tertile exposure.

CONCLUSIONS

Early-pregnancy plasma malondialdehyde concentration is positively associated with subsequent preeclampsia risk independent of plasma lipid concentrations. These results support lipid peroxidation as an etiologic component of preeclampsia.