Cardiovascular Physiology of Pregnancy

Anesthetic management for cesarean delivery in a patient with uncorrected pulmonary atresia, ventricular septal defect and major aortopulmonary collateral arteries

Pulmonary atresia witha ventricular septal defect and major aortopulmonary collateral arteries is an extremely rare congenital disorder characterized by a high risk of maternal mortality. We present the case of a 24-year-old primigravid woman with uncorrected pulmonary atresia, ventricular septal defect and major aortopulmonary collateral arterieswho presented at 35+5 weeks' gestation. Based on the pathophysiology of the congenital cardiac lesion, cesarean delivery was performed under epidural anesthesia under management by a multidisciplinary team. This report highlights the anesthesia management of a rare uncorrected congenital cardiac lesion for cesarean delivery.

Anesthetic Treatment of Cardiac Disease During Pregnancy

PURPOSE OF REVIEW

This review summarizes the pathophysiology, peripartum treatment, and anesthetic management of parturients with cardiac disease. Valvular disease, coronary disease, and cardiomyopathy are specifically addressed in the context of the normal physiologic changes of pregnancy. We offer recommendations for anesthetic approaches, hemodynamic goals with an emphasis on interdisciplinary planning between anesthesiologists, cardiologists, cardiothoracic surgeons, obstetricians, maternal fetal medicine specialists, and neonatologists.

RECENT FINDINGS

Vaginal delivery with neuraxial analgesia can be well tolerated by many pregnant patients with cardiac disease when coordinated by an interdisciplinary team of experts. Cardiac disease in pregnancy can present a significant challenge for the interdisciplinary care team. A detailed understanding of each patient's cardiac pathology and the physiologic changes of pregnancy are critical to ensure a safe and successful labor and delivery. Optimized medical therapy in the peripartum period and neuraxial anesthesia with the judicious use of vasoactive agents can be of great benefit for these parturients. As is generally the case, cesarean delivery should be primarily reserved for obstetric indications and maternal wellbeing, with careful consideration of the fetus to guide best practices.

Morphofunctional cardiac changes in pregnant women: associations with biomarkers

Objective

This longitudinal study was performed to determine changes in echocardiography parameters in association with various biomarker levels in pregnancy/postpartum.

Methods

Fifty-one healthy pregnant women underwent echocardiography with simultaneous determination of blood levels of five biomarkers at each of the first, second and third trimesters of pregnancy, immediately postpartum within 1 week after childbirth and approximately 1 month postpartum. Data on 255 echocardiography scans (five times per woman) and biomarkers were analysed.

Results

Left ventricular end-diastolic dimension, left atrial (LA) volume index and left ventricular (LV) mass index increased with advancing gestation and reached the maximum immediately postpartum concomitant with the highest brain natriuretic peptide (BNP), N-terminal pro B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hs-TnI) and creatine kinase MB levels. The inferior vena cava diameter was significantly reduced in the third trimester compared with that in the first trimester and the peak occurred immediately after childbirth. In 255 paired measurements, hs-TnI level was significantly positively correlated with LA volume index and LV mass index; BNP and NT-proBNP were significantly positively correlated with LA volume index and estimated glomerular filtration rate (eGFR) was significantly positively correlated with the average of early diastolic septal and lateral mitral annular velocity (e').

Conclusions

Maximal cardiac changes in morphology occurred postpartum within 1 week after childbirth, not during pregnancy. BNP/NT-proBNP, hs-TnI and eGFR reflected cardiac changes in pregnancy.

Cardiac Arrhythmias and Pregnancy

PURPOSE OF REVIEWS

In this review, the challenges of managing cardiac arrhythmias and syncope in the setting of pregnancy will be discussed.

RECENT FINDINGS

Arrhythmias in pregnancy are increasing, as diagnostic and therapeutic options have advanced and women are older at the time of gestation. Atrial fibrillation has become the most common arrhythmia in pregnancy. Inherited arrhythmia has become a more common entity, with advances in treatments and genetic testing, and require specialized treatments in pregnancy. The majority of arrhythmias in pregnancy are benign. The potential risk of increased cardiac morbidity and mortality exists for mother and fetus, especially in women with structural heart disease, which is becoming increasingly common. Early evaluation, diagnosis, and appropriate treatment are necessary to achieve optimal outcomes for both mother and fetus.

Routine blood tests during pregnancy for predicting future increases in risk of cardiovascular morbidity

OBJECTIVE

To examine the association between routine blood tests during pregnancy and future risk of cardiovascular morbidity.

METHODS

The present case-control study was conducted among women who delivered at a teaching hospital in Israel between January 1, 2000, and December 31, 2012. The cohort comprised women who were subsequently hospitalized owing to cardiovascular morbidity (case group) and age-matched non-hospitalized women (control group). Blood levels of creatinine, glucose, potassium, urea, and uric acid were measured during pregnancy. Only women with at least one test result available for all five measurements were included. The relationship between upper quartile blood test values and cardiovascular hospitalization was assessed.

RESULTS

The study included 4115 women (212 in the case group and 3903 in the control group). Three measures were associated with a future risk of cardiovascular morbidity requiring hospitalization: creatinine (hazard ratio [HR] 1.86, 95% confidence interval [CI] 1.37-2.53; P<0.001); potassium (HR 1.48, 95% CI 1.09-2.01; P=0.013), and urea (HR 1.60, 95% CI 1.17-2.19; P=0.003). The number of blood test results in the upper quartile also increased such risk. The HRs for two tests and at least three tests were 1.65 (95% CI 1.06-2.56; P=0.026) and 3.32 (95% CI 2.19-5.04; P<0.001), respectively.

CONCLUSIONS

Future cardiovascular morbidity was predicted by routine blood tests during pregnancy.

Reducing Psychological Stress in Peripartum Women With Heart Rate Variability Biofeedback: A Systematic Review

Peripartum women are exposed to a variety of stressors that have adverse health consequences for the maternal-child dyad (e.g., impaired bonding). To combat these adverse health consequences, heart rate variability biofeedback (HRVBF) may be implemented by holistic nurses to aid peripartum women experiencing a high level of stress. A systematic review was completed using the guidelines established in the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. To be included in the review, studies had to meet the following criteria: (a) published scientific articles, (b) studies published in English, (c) experimental, quasi-experimental, or case reports, (d) use of HRVBF as the main treatment, (e) use of psychological stress as a dependent variable, and (f) studies published until December 2017. The major findings of this review can be described as follows: (a) HRVBF and psychological stress in peripartum women are related concepts, (b) peripartum women who completed HRVBF report a reduction in stress compared with participants who did not receive HRVBF, and (c) there is currently no information on the effectiveness of HRVBF on psychological stress in the first and early second trimester of pregnancy. Overall, this systematic review of the literature provides objective evidence that HRVBF may be a potential beneficial adjuvant treatment for stress management in peripartum women.

Ventricular efficiency in pregnant women with congenital heart disease

BACKGROUNDS

Pregnant women with congenital heart disease (CHD) are at risk of cardiovascular events during pregnancy as well as postpartum. The aim of our study is to address the feasibility of echocardiography-derived ventricular-arterial coupling during pregnancy and postpartum among women with CHD.

METHODS

In 31 pregnant women with CHD, we performed serial echocardiography at the first and third trimesters, early and late postpartum. The indices of contractility (single-beat determined end-systolic elastance, Ees_ab) and afterload (effective arterial elastance, Ea) were approximated on the basis of the systemic blood pressure and systemic ventricular volume. The ratio of stroke work and pressure-volume area (SW/PVA) representing ventricular efficiency was also calculated.

RESULTS

Age at the delivery was 28 (24-31) years. ZAHARA score was 0.75 (0.75-1.50). Gestational age and birth weight of newborns were 38 (37-39) weeks and 2.73 (2.42-2.92) kg, respectively. Heart rate, systemic ventricular end-diastolic volume and stroke volume significantly increased from the first trimester to the third trimester and reversed postpartum to the values of the first trimester. Ees_ab and Ea significantly decreased from the first trimester to the third trimester (Ees_ab; 4.90 [2.86-7.14] vs 3.41 [2.53-4.61] mm Hg/ml, p = 0.0001, Ea; 2.83 [1.74-3.30] vs 2.18 [1.67-2.68] mm Hg/ml, p = 0.0012), and reversed early postpartum parallelly. Ejection fraction and SW/PVA remained unchanged throughout pregnancy and postpartum.

CONCLUSIONS

Echocardiography-derived ventricular-arterial coupling is feasible to understand ventricular function in pregnant women with CHD.

Cerebral Osmolytes and Plasma Osmolality in Pregnancy and Preeclampsia: A Proton Magnetic Resonance Spectroscopy Study

BACKGROUND

Cerebral complications contribute substantially to mortality in preeclampsia. Pregnancy calls for extensive maternal adaptations, some associated with increased propensity for seizures, but the pathophysiology behind the eclamptic seizures is not fully understood. Plasma osmolality and sodium levels are lowered in pregnancy. This could result in extrusion of cerebral organic osmolytes, including the excitatory neurotransmitter glutamate, but this remains to be determined. The hypothesis of this study was that cerebral levels of organic osmolytes are decreased during pregnancy, and that this decrease is even more pronounced in women with preeclampsia.

METHODS

We used proton magnetic resonance spectroscopy to compare levels of cerebral organic osmolytes, in women with preeclampsia (n = 30), normal pregnancy (n = 32), and nonpregnant controls (n = 16). Cerebral levels of organic osmolytes were further correlated to plasma osmolality and plasma levels of glutamate and sodium.

RESULTS

Compared to nonpregnant women, women with normal pregnancy and preeclampsia had lower levels of the cerebral osmolytes, myo-inositol, choline and creatine (P = 0.001 or less), and all these metabolites correlated with each other (P < 0.05). Women with normal pregnancies and preeclampsia had similar levels of osmolytes, except for glutamate, which was significantly lower in preeclampsia. Cerebral and plasma glutamate levels were negatively correlated with each other (P < 0.008), and myo-inositol, choline and creatine levels were all positively correlated with both plasma osmolality and sodium levels (P < 0.05).

CONCLUSIONS

Our results indicate that pregnancy is associated with extrusion of cerebral organic osmolytes. This includes the excitatory neurotransmitter glutamate, which may be involved in the pathophysiology of seizures in preeclampsia.

Developmental origins of pregnancy-induced cardiac changes: establishment of a novel model using the atrial natriuretic peptide gene-disrupted mice

Pregnancy evokes many challenges on the maternal cardiovascular system that may unmask predispositions for future disease. This is particularly evident for women who develop pregnancy-related disorders, for example, pre-eclampsia and gestational diabetes or hypertension. Such pregnancy-related syndromes increase the risk for cardiovascular disease (CVD) postpartum. As a result, pregnancy has been termed as a cardiovascular stress test and an indicator or marker to predict the development of CVD later in life. In addition, pregnancy-related disorders impact the development of offspring also placing them at a higher risk for disease. Utilizing pregnancy as a physiological stressor, the current investigation sought to determine whether the cardiovascular system of offspring exposed to gestational hypertension in utero would respond adversely to the stress of pregnancy. Heterozygous atrial natriuretic peptide gene-disrupted (ANP^+/-) offspring were generated by either crossing male wildtype ANP^+/+ with female knockout ANP^-/- to produce ANP^+/-KO mice or crossing female wildtype ANP^+/+ with male knockout ANP^-/- to produce ANP^+/-WT mice. To study the cardiovascular stress induced by pregnancy, female ANP^+/-WT and ANP^+/-KO mice were mated with male wildtype ANP^+/+ mice to initiate pregnancy. Cardiac size and molecular expression of the renin-angiotensin (RAS) and natriuretic peptide systems (NPS) were compared between offspring groups. Our data demonstrate that gestational hypertension and lack of maternal ANP did not significantly impact the progression and regression of pregnancy-induced cardiac hypertrophy over gestation and postpartum in ANP^+/- offspring. Additionally, the molecular cardiac expression of the RAS and NPS did not differ between offspring groups. Future investigation should assess potential differences in cardiac function and the impact of fetal-programming on offspring cardiovascular adaptations during pregnancy in more severe models of pregnancy-related hypertensive syndrome such as angiotensin II or isoproterenol infusion.

A novel human S10F-Hsp20 mutation induces lethal peripartum cardiomyopathy

Heat shock protein 20 (Hsp20) has been shown to be a critical regulator of cardiomyocyte survival upon cardiac stress. In this study, we investigated the functional significance of a novel human Hsp20 mutation (S10F) in peripartum cardiomyopathy. Previous findings showed that cardiac-specific overexpression of this mutant were associated with reduced autophagy, left ventricular dysfunction and early death in male mice. However, this study indicates that females have normal function with no alterations in autophagy but died within a week after 1-4 pregnancies. Further examination of mutant females revealed left ventricular chamber dilation and hypertrophic remodelling. Echocardiography demonstrated increases in left ventricular end-systolic volume and left ventricular end-diastolic volume, while ejection fraction and fractional shortening were depressed following pregnancy. Subsequent studies revealed that cardiomyocyte apoptosis was elevated in mutant female hearts after the third delivery, associated with decreases in the levels of Bcl-2/Bax and Akt phosphorylation. These results indicate that the human S10F mutant is associated with dysregulation of cell survival signalling, accelerated heart failure and early death post-partum.

Self-monitoring of blood pressure during pregnancy: an observational study in the obstetrical waiting room

OBJECTIVE

The aim of this study was to assess the feasibility of self-monitoring of blood pressure with a semiautomatic device in pregnant women.

PARTICIPANTS AND METHODS

Women attending routine obstetrical ultrasound scanning were invited to participate. The hospital staff initially demonstrated and instructed each participant in correct measurement and then took three measurements on both arms. The participant then repeated the measurements and filled an evaluation questionnaire. We used a validated semiautomatic device for all measurements. Mean values were calculated for systolic, diastolic and mean arterial blood pressure (MAP) and were compared using the paired sample t-test. Mean values and differences of systolic and diastolic pressure were plotted in Bland-Altman plots to test the agreement of the measurements. Finally, a mean evaluation score was calculated.

RESULTS

One hundred pregnant women were included in the study. Mean values of systolic, diastolic and MAP were 110.6, 69.7 and 83.3 mmHg, respectively, as assessed by the hospital staff. The corresponding self-measurements were 111.4, 70.2 and 83.9 mmHg, respectively. Mean differences between hospital and self-measurements were 0.79 mmHg for systolic [P=0.052, 95% confidence interval (CI)=-0.008 to 1.58], 0.49 mmHg for diastolic (P=0.056, 95% CI=-0.01 to 0.99) and 0.59 mmHg for MAP (P=0.019, 95% CI=0.099-1.08). The mean evaluation score was 9.2 of 10.

CONCLUSION

Differences between hospital staff and self-measurements in systolic, diastolic and MAP are within acceptable international standards. The semiautomatic device Microlife-VSA is well suited for self-measurement; however, safety studies on the use of home measurements in hypertensive pregnancies are still warranted.

Extracorporeal Life Support as Salvage Therapy for Massive Pulmonary Embolus and Cardiac Arrest in Pregnancy

BACKGROUND

Massive pulmonary embolus (PE) with prolonged cardiac arrest in the setting of pregnancy has few treatment options. Selections are further restricted if there are contraindications to the standard therapies of embolectomy and thrombolysis. We report a case of extracorporeal life support (ECLS) used as salvage therapy for a critically ill pregnant patient.

CASE REPORT

A 21-year-old woman presented to a small rural hospital with chest pain, dyspnea, hypoxia, and syncope. In their emergency department, she suffered 2 episodes of cardiac arrest requiring cardiopulmonary resuscitation, and fetal demise followed. A computed tomography scan revealed a saddle PE. She was transferred to our tertiary care hospital and arrived critically ill, on multiple vasopressors, and in cardiogenic shock. Because standard treatments, namely thrombolysis and embolectomy, were contraindicated in this case, ECLS was employed for 7 days. She was discharged home after 23 days, and at follow-up 5 months after her admission, she was found to have made a near-complete recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ECLS is a viable option as salvage therapy for pregnant patients with massive PE who have contraindications to thrombolysis and embolectomy.

Impedance cardiography as tool for continuous hemodynamic monitoring during cesarean section: randomized, prospective double blind study

BACKGROUND

Impedance Cardiography (ICG) is a non-invasive tool for continuous hemodynamic monitoring. Aims of our study were to assess the utility of ICG to evaluate the hemodynamic impact of 6 mg (GL6) vs 8 mg (GL8) levobupivacaine combined with fentanyl in healthy patients undergoing elective cesarean section; secondary, to compare the duration and quality of analgesia and anesthesia.

METHODS

Sixty-two women receiving combined spinal-epidural (CSE) for elective cesarean delivery were randomly allocated to GL6 or GL8 groups. Mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance index (SVRI), heart rate (HR), stroke volume index (SVI) were recorded from Tbaseline to 31 min after CSE by ICG. Sensory and motor blocks, patients and surgeons satisfaction, neonatal data were also recorded.

RESULTS

Fifteen of 32 patients in GL6 and 15 of 30 patients in GL8 experienced hypotension at T2 vs Tbaseline (P < .001) and SVRI reduction (P = .035 and P < .001 respectively). MAP, CI and SVRI were always slightly higher in GL6 vs GL8. HR and SVI remained stable until the end of surgery in all patients. Total ephedrine requirements was higher in GL8 (P = .010). The onset and offset time of sensory and motor block were similar in both groups, but the number of patients with motor block was lower in GL6 vs GL8 (P = .001). Patients and surgeon satisfaction scores, the number of patients needed systemic rescue doses, neonatal data were similar in both groups.

CONCLUSIONS

ICG is a useful noninvasive tool to monitor continuously hemodynamics during cesarean section. The hemodynamic stability, the satisfying sensory block and rapid mobilization provided by low levobupivacaine dose may be particularly advantageous in obstetric patients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03170427 . Retrospectively Registered (Date of registration: May 2017).

Relationship between the left ventricular size and the amount of trabeculations

Contemporary imaging modalities offer noninvasive quantification of myocardial deformation; however, they make gross assumptions about internal structure of the cardiac walls. Our aim is to study the possible impact of the trabeculations on the stroke volume, strain, and capacity of differently sized ventricles. The cardiac left ventricle is represented by an ellipsoid and the trabeculations by a tissue occupying a fixed volume. The ventricular contraction is modeled by scaling the ellipsoid whereupon the measurements of longitudinal strain, end-diastolic, end-systolic, and stroke volumes are derived and compared. When the trabeculated and nontrabeculated ventricles, having the same geometry and deformation pattern, contain the same amount of blood and contract with the same strain, we observed an increased stroke volume in our model of the trabeculated ventricle. When these ventricles contain and eject the same amount of blood, we observed a reduced strain in the trabeculated case. We identified that a trade-off between the strain and the amount of trabeculations could be reached with a 0.35- to 0.41-cm dense trabeculated layer, without blood filled recesses (for a ventricle with end-diastolic volume of about 150 mL). A trabeculated ventricle can work at lower strains compared to a nontrabeculated ventricle to produce the same stroke volume, which could be a possible explanation why athletes and pregnant women develop reversible signs of left ventricular noncompaction, since the trabeculations could help generating extra cardiac output. This knowledge might help to assess heart failure patients with dilated cardiomyopathies who often show signs of noncompaction.

Serum nitric oxide levels in healthy pregnant women: a case- control study in a tertiary facility in Ghana

Background

Pregnancy is associated with significant changes in maternal cardiovascular system which regulates oxygen and nutrient supply to the growing foetus. Nitric oxide, a physiologic vascular smooth muscle relaxant regulates blood flow and therefore may play a role in the cardiovascular changes in pregnancy. The study aimed to determine the levels and changes in maternal serum nitric oxide levels during healthy pregnancy.

Methods

A case-control study was conducted among 32 healthy non-pregnant women as controls and 100 healthy pregnant women (consisting of 33 first trimester, 37 s trimester, and 30 third trimester) as cases. Subjects were consecutively recruited into the study after obtaining an informed consent and meeting the inclusion criteria. Griess Reagent method was used to determine serum nitric oxide levels.

Results

There were no statistically significant difference in the ages and parity of recruited cases and controls. Mean arterial blood pressures were significantly lower (p = 0.009) and serum nitric oxide levels were significantly higher (p < 0.001) in healthy pregnant women compared to healthy non-pregnant women. There was a non-significant progressive increase in serum nitric oxide levels during healthy normal pregnancy.

Conclusions

The finding of a significantly reduced blood pressures and a significant increase in serum nitric oxide levels in healthy pregnancy may suggest a role of nitric oxide in vascular adaptation in pregnancy.

Taking cardiology clinical trials to the next level: A call to action

Physicians previously perceived heart disease to be a man's disease; yet, since 1984, more women have died of ischemic heart disease. Because women who develop obstructive coronary heart disease and heart failure tend to do so 10 years later than men, cardiology clinical trials that use arbitrary age cutoffs or exclusion criteria based on comorbidities and polypharmacy often limit the pool of potential participants to a greater extent for women. Issues related to trial design and insufficient accounting for female-predominant disease patterns have contributed to low rates of enrollment of women in certain domains of cardiology research. Accordingly, women do not benefit from as rich an evidence base for cardiology as men. Here, we review major sex differences in heart disease and discuss areas of cardiology research in which women have been underrepresented. Considering the widespread sex differences in cardiovascular structure and function, it is important to include balanced numbers of women and men in cardiovascular clinical trials. Beyond inclusion, sex-specific reporting is also essential. Moreover, with ongoing developments of clinical-trial methodology, it is imperative to seek innovative ways to learn as much as possible about how interventions behave in women and men. Adaptive trials are specifically identified as promising opportunities to consider sex-based analyses at interim stages, allowing sex-specific flexibility as these trials unfold. Finally, we emphasize the importance of factoring sex as a biological variable into the design, analysis, and reporting of preclinical research, because this research critically informs the design and execution of clinical trials.

Pregnancy-Associated Stroke

Cerebrovascular accident, or stroke, is the fourth leading cause of death for all women and the eighth leading cause of pregnancy-associated death. The physiologic changes of pregnancy increase the risk of cerebrovascular accident for women. With current incidence rates, a facility with 3300 births per year can anticipate caring for one woman with a pregnancy-related stroke at least every 2 years. All maternity care providers must be able to assess women experiencing stroke-like symptoms and initiate timely care to mitigate brain tissue damage, decrease long-term morbidity, and prevent mortality. The 2 main types of stroke, ischemic and hemorrhagic, have similar presenting symptoms but very different pathophysiology and treatment. This article reviews assessment and initial treatment of pregnant and postpartum women experiencing stroke and provides guidance for subsequent maternity and primary care to assist front-line perinatal care providers who may be the first to treat affected women or may resume primary care after diagnosis.

Effect of a lifestyle intervention in obese infertile women on cardiometabolic health and quality of life: A randomized controlled trial

Background

The prevalence of obesity, an important cardiometabolic risk factor, is rising in women. Lifestyle improvements are the first step in treatment of obesity, but the success depends on factors like timing and motivation. Women are especially receptive to advice about lifestyle before and during pregnancy. Therefore, we hypothesize that the pre-pregnancy period provides the perfect window of opportunity to improve cardiometabolic health and quality of life of obese infertile women, by means of a lifestyle intervention.

Methods and findings

Between 2009–2012, 577 infertile women between 18 and 39 years of age, with a Body Mass Index of ≥ 29 kg/m2, were randomized to a six month lifestyle intervention preceding infertility treatment, or to direct infertility treatment. The goal of the intervention was 5–10% weight loss or a BMI < 29 kg/m². Cardiometabolic outcomes included weight, waist- and hip circumference, body mass index, systolic and diastolic blood pressure, fasting glucose and insulin, HOMA-IR, hs-CRP, lipids and metabolic syndrome. All outcomes were measured by research nurses at randomization, 3 and 6 months. Self-reported quality of life was also measured at 12 months. Three participants withdrew their informed consent, and 63 participants discontinued the intervention program. Intention to treat analysis was conducted. Mixed effects regression models analyses were performed. Results are displayed as estimated mean differences between intervention and control group. Weight (-3.1 kg 95% CI: -4.0 to -2.2 kg; P < .001), waist circumference (-2.4 cm 95% CI: -3.6 to -1.1 cm; P < .001), hip circumference (-3.0 95% CI: -4.2 to -1.9 cm; P < .001), BMI (-1.2 kg/m² 95% CI: -1.5 to -0.8 kg/m²; P < .001), systolic blood pressure (-2.8 mmHg 95% CI: -5.0 to -0.7 mmHg; P = .01) and HOMA-IR (-0.5 95% CI: -0.8 to -0.1; P = .01) were lower in the intervention group compared to controls. Hs-CRP and lipids did not differ between groups. The odds ratio for metabolic syndrome in the intervention group was 0.53 (95% CI: 0.33 to 0.85; P < .01) compared to controls. Physical QoL scores were higher in the lifestyle intervention group (2.2 95% CI: 0.9 to 3.5; P = .001) while mental QoL scores did not differ.

Conclusions

In obese infertile women, a lifestyle intervention prior to infertility treatment improves cardiometabolic health and self-reported physical quality of life (LIFEstyle study: Netherlands Trial Register: NTR1530).

Hemodynamic and Electrocardiographic Aspects of Uncomplicated Singleton Pregnancy

Pregnancy is associated with significant changes in maternal hemodynamics, which are triggered by profound systemic vasodilation and mediated through the autonomic nervous system as well as the renin-angiotensin-aldosterone system. Vascular function changes to help accommodate an increase in intravascular volume due to blood volume expansion associated with pregnancy while maintaining the efficiency of ventricular-arterial coupling and diastolic perfusion pressure. The heart undergoes physiological (eccentric) hypertrophy due to increased volume load and cardiac stroke work, whereas the functional change of the left ventricle remains controversial. There are changes in cardiac electrical activity during pregnancy which can be detected in the electrocardiogram that are not related to disease. Sympathetic activation is a common phenomenon during uncomplicated pregnancy and may be a compensatory mechanism induced by profound systemic vasodilation and a decrease in mean arterial pressure. Despite marked sympathetic activation, vasoconstrictor responsiveness is blunted during uncomplicated pregnancy. There are race and ethnic differences in maternal hemodynamic adaptations to uncomplicated pregnancy, which may be attributed to differences in socioeconomic status or in prevalence rates of cardiovascular risk factors.

Association between total dose of ritodrine hydrochloride and pulmonary oedema in twin pregnancy: a retrospective cohort study in Japan

OBJECTIVE

Pulmonary oedema is recognised as a severe side effect of ritodrine hydrochloride. Recently, the number of twin pregnancies has been increasing. Few studies have reported the association between total dose of ritodrine hydrochloride prior to delivery and pulmonary oedema in twin pregnancy. We aimed to examine this association and determine the optimal cut-off threshold of total ritodrine hydrochloride dose to predict the incidence of pulmonary oedema in twin pregnancy based on obstetric records.

DESIGN

Retrospective cohort study.

SETTING

Yamanashi Prefectural Central Hospital, Japan.

PARTICIPANTS

Two hundred and twenty-six women with twin pregnancy who delivered at Yamanashi Prefectural Central Hospital between September 2009 and November 2016.

METHODS

The obstetric records of the participants were analysed. We defined 1 unit of ritodrine hydrochloride as 72 mg per 24 hours continuous transfusion at 50 µg/min to calculate the dose of ritodrine used for tocolysis.

OUTCOME MEASURES

Multivariable logistic regression analysis was performed to examine the association between total dose of ritodrine hydrochloride used for threatened preterm labour and pulmonary oedema, while controlling for potential confounding factors. Then, a receiver-operating characteristic curve was used to determine the optimal cut-off of total ritodrine dose to predict pulmonary oedema incidence.

RESULTS

Mean maternal age was 32 (range, 18-46) years; 143 participants were nulliparous (63.3%), 109 had (48.2%) term deliveries and 194 (85.8%) had caesarean deliveries. The overall incidence of pulmonary oedema was 13.7% (31/226). Multivariable analysis showed that the total dose of ritodrine was significantly associated with pulmonary oedema (adjusted OR 1.02; 95% CI 1.004 to 1.03). The best cut-off point to predict the incidence of pulmonary oedema was 26 units (1872 mg) (sensitivity, 61.3%; specificity, 87.8%).

CONCLUSION

Our results suggest that consideration of the total dose of ritodrine hydrochloride is helpful in the management of patients with threatened preterm labour in twin pregnancy.

Impaired maternal hemodynamics in morbidly obese women: a case-control study

OBJECTIVE

Maternal obesity is associated with significant pregnancy complications and is a risk factor for the development of hypertensive disorders of pregnancy as well as other adverse outcomes. There are few data regarding the hemodynamic aberrations observed in maternal obesity. The aim of this study was to investigate maternal hemodynamics in morbidly obese women.

METHODS

This was a prospective, case-control study of morbidly obese women (body mass index (BMI) ≥ 40 kg/m² ) and controls (BMI 20-29.9 kg/m² ). The control population was matched for maternal age and gestational age. BMI was calculated based on maternal height and weight at the time of recruitment to the study, which occurred on the same day as the hemodynamic assessment. Pregnant women in the second or third trimester of pregnancy were included. Women who were found to be hypertensive at any time were excluded from the study. A USCOM-1A® device was used to assess hemodynamic parameters (heart rate, stroke volume (SV), cardiac output and systemic vascular resistance (SVR)). The parameters were corrected for body surface area (BSA) to provide the SV index (SVI), cardiac index (CI) and SVR index (SVRI). Mann-Whitney U-test was used to compare the medians of the hemodynamic variables between the two groups.

RESULTS

In total, 23 morbidly obese women and 327 controls were included in the analysis. There was no difference in maternal (P = 0.506) or gestational (P = 0.693) age at recruitment between the groups. Mean arterial pressure was higher both at pregnancy booking (90 vs 80 mmHg, P < 0.001) and study recruitment (91 vs 85 mmHg, P < 0.001) in the obese group compared with the controls. Heart rate was higher in the obese group (P = 0.003), but there was no difference in SV (P = 0.271), cardiac output (P = 0.238) or SVR (P = 0.635). Following correction of these parameters for BSA, compared with the control group, SVI (34 vs 45 mL/m² , P < 0.001) and CI (2.96 vs 3.64 L/min/m² , P < 0.001) were significantly reduced in the obese group, whereas SVRI was significantly higher (2354 vs 1840 dynes × s/cm⁵ , P < 0.001).

CONCLUSIONS

The findings of our study suggest that cardiac function is significantly altered in morbidly obese pregnant women. In order to make appropriate comparisons between individuals, it is imperative that hemodynamic parameters are indexed for BSA, as is standard practice in pediatric cardiology. The novel finding of reduced CI in morbidly obese pregnant women may explain the predisposition to pre-eclampsia and other adverse outcomes in this population and warrants further investigation. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Maternal hemodynamics in late gestation and immediate postpartum in singletons vs. twin pregnancies

PURPOSE

Differences in hemodynamic changes during a cesarean section (CS) between twin and singleton pregnancies are poorly defined. The Non-Invasive Cardiac System (NICaS) is an impedance device that measures cardiac output (CO) and its derivatives. We compared maternal cardiac parameters using NICaS™ in singleton and twins before and during delivery, as well at the early puerperium in healthy women undergoing CS at term.

METHODS

This prospective longitudinal study included women with twin (n = 27) or singleton pregnancies (n = 62) whose hemodynamic parameters were assessed by NICaS before an elective CS, after spinal anesthesia, immediately after delivery, after fascia closure, and within 24-36 and 48-72 h postpartum.

RESULTS

By 24-36 h postpartum, the mean arterial pressure and the total peripheral resistance equaled preoperative values in both groups. The CO increased throughout the CS and peaked immediately after delivery in the singleton group (P < 0.0001), after which it abruptly began to decline until reaching a nadir 24-36 h after delivery (P < 0.0001), while it remained steady throughout the CS and then dropped until 24-36 h after delivery in the twin group (P < 0.05). None of the studied parameters differed significantly between the groups for the 24-36 and 48-72 h postpartum measurements.

CONCLUSIONS

Hemodynamic parameters immediately before, during and shortly after CS in singleton and twin pregnancies are equivalent. Further evaluations of the value of NICaS™ in assessing cardiovascular-related pregnancy complications are warranted.

Physiology of blood pressure relevant to managing hypertension in pregnancy

PURPOSE

Pregnancy causes physiological changes in maternal organ systems, and blood pressure (BP) is one of the variables affected. This review is focusing on the physiology of BP relevant to the management of hypertension in pregnancy.

MATERIALS AND METHODS

A detailed literature search was performed using electronic databases (including WorldCat, PubMed, MEDLINE, Google Scholar) to retrieve and review reports related to physiology of BP in pregnancy.

RESULTS

During pregnancy, there is vasodilation caused by mediators such as increased levels of progesterone and nitric oxide. The vasodilation leads to a reduction in vascular resistance, BP, and renal blood flow. In compensation, the following postulated events occur: activation of renin-angiotensin-aldosterone axis, resetting of osmotic threshold for thirst, and an increase in the production of vasopressin. Sodium and water conservation ensue to increase the total body water, end-diastolic volume, cardiac output, and BP. The increase in cardiac output incompletely compensates for the decreased vascular resistance, and BP therefore decreases in midpregnancy and returns to prepregnancy level toward term.

CONCLUSIONS

An understanding of the physiological changes in BP is essential for appropriate management of pregnancy-related hypertension.

Imaging of Cardiovascular Disease in Pregnancy and the Peripartum Period

OPINION STATEMENT

Cardiovascular disease is an important cause of morbidity and mortality during pregnancy and the postpartum period. During pregnancy, the cardiovascular system undergoes extensive hemodynamic, hormonal, and microstructural changes which may exacerbate a preexisting underlying cardiovascular condition or predispose to cardiovascular complications not typically seen in young healthy women. Such conditions include spontaneous coronary artery dissection, atherosclerotic coronary artery disease, and peripartum cardiomyopathy. When evaluating this patient population, the diagnostic strategy should be tailored to specifically assess this distinct disease spectrum. The choice of imaging techniques must also consider potential risks to both the mother and child; a unique challenge of diagnostic imaging during pregnancy. The risk of radiation from radiography, computed tomography, and nuclear medicine imaging; iodinated and gadolinium-based contrast media for computed tomography and magnetic resonance imaging respectively; and heat deposition from sonography are of special importance during pregnancy. A thorough understanding of pregnancy-specific cardiovascular complications and the capabilities and risks of available diagnostic imaging modalities is crucial to appropriately manage the pregnant patient.

Experimental preeclampsia in rats affects vascular gene expression patterns

Normal pregnancy requires adaptations of the maternal vasculature. During preeclampsia these adaptations are not well established, which may be related to maternal hypertension and proteinuria. The effects of preeclampsia on the maternal vasculature are not yet fully understood. We aimed to evaluate gene expression in aortas of pregnant rats with experimental preeclampsia using a genome wide microarray. Aortas were isolated from pregnant Wistar outbred rats with low-dose LPS-induced preeclampsia (ExpPE), healthy pregnant (Pr), non-pregnant and low-dose LPS-infused non-pregnant rats. Gene expression was measured by microarray and validated by real-time quantitative PCR. Gene Set Enrichment Analysis was performed to compare the groups. Functional analysis of the aorta was done by isotonic contraction measurements while stimulating aortic rings with potassium chloride. 526 genes were differentially expressed, and positive enrichment of “potassium channels”, “striated muscle contraction”, and “neuronal system” gene sets were found in ExpPE vs. Pr. The potassium chloride-induced contractile response of ExpPE aortic rings was significantly decreased compared to this response in Pr animals. Our data suggest that potassium channels, neuronal system and (striated) muscle contraction in the aorta may play a role in the pathophysiology of experimental preeclampsia. Whether these changes are also present in preeclamptic women needs further investigation.

Maternal Heart Rate Variability during the First Stage of Labor

Labor necessitates continuous adjustments of cardiac autonomic reflexes by alternate activation of the sympathetic and parasympathetic nervous systems. The division of the autonomic nervous system (ANS) that predominates during the first stage of labor is unclear and needs to be further investigated. The study aimed to compare heart rate variability (HRV) in pregnant women in the third trimester with those during the first stage of labor. We conducted a case-control study at Saad Abul Ela Maternity Hospital, Khartoum, Sudan. Forty-five women with singleton, live neonates in the first stage of labor and 45 women in the third trimester (but not in labor) were enrolled as case and control groups, respectively. Data on the medical history, obstetrics history, and clinical examinations that were performed in all of the studied women were obtained using prearranged questionnaires. Cardiac autonomic modulation (CAM) of the heart was examined in both groups based on time and frequency domain HRV indices. There were no significant differences in age, parity, body mass index, and hemoglobin levels between the two groups. Pregnant women in labor had significantly higher LnSDNN, LnRMSSD, LnTP, LnVLF, LnLF, LnHF, LF Norm, and LnLF/HF ratio, but lower HF Norm compared with controls (P < 0.001). These findings remained unchanged when possible confounders were controlled for using regression analysis. Our findings suggest a significant increase in indictors of sympathetic CAM, namely LF Norm and LnLF/HF, during labor. Sympathetic hypertonia associated with labor is unlikely to increase the risk of cardiac events because sympathetic CAM simultaneously increases with global HRV. Increased HRV during labor may be explained by parasympathetic activation as indicated by higher LnHF and LnRMSSD at the time of delivery.

The hemodynamic effects of pregnancy on the lower extremity venous system

OBJECTIVE

Pregnancy has significant effects on the lower extremity venous system. Increasing venous pressure and blood volume, in combination with reduced flow rates within the deep veins, predisposes pregnant women to both primary and secondary chronic venous insufficiency (CVI). This review article highlights the specific physiologic and hemodynamic changes that occur during pregnancy and examines the nonpharmacologic, pharmacologic, and invasive interventions that are appropriate for both prophylaxis and treatment of CVI and venous thromboembolism (VTE).

METHODS

This study is a review article of the key literature related to VTE and CVI in pregnancy.

RESULTS

Significant hemodynamic changes occur in the lower extremities during pregnancy. Although well documented and essential to fetal development, these changes can have a negative impact on the maternal lower extremity venous circulation. Consequences of pregnancy can result in venous disease only during pregnancy or, particularly in the multiparous patient, can progress to CVI. An abundance of literature and guidelines exist for the management of VTE during pregnancy; however, the quality and extent of literature based around the management of primary CVI during pregnancy are modest at best.

CONCLUSIONS

The physiologic changes throughout the arterial and venous systems during pregnancy are well documented. However, there is a paucity of data available to construct guidelines for care, particularly in the pregnant patient with symptomatic superficial venous insufficiency. Further investigation in the form of prospective randomized trials is required to establish appropriate guidelines for treatment.

Spontaneous Coronary Artery Dissection Associated With Pregnancy

BACKGROUND

Spontaneous coronary artery dissection (SCAD) is the most common cause of pregnancy-associated myocardial infarction and remains poorly characterized.

OBJECTIVES

This study sought to assess presentation, clinical factors, and outcomes of pregnancy-associated spontaneous coronary artery dissection (P-SCAD) compared with spontaneous coronary artery dissection not associated with pregnancy (NP-SCAD).

METHODS

A Mayo Clinic registry was established in 2010 to include comprehensive retrospective and prospective SCAD data. Records were reviewed to identify women who were pregnant or ≤12 weeks postpartum at time of SCAD. Complete records were available for 323 women; 54 women met criteria for P-SCAD (4 during pregnancy) and they were compared with 269 women with NP-SCAD.

RESULTS

Most events occurred within the first month postpartum (35 of 50). Compared with NP-SCAD, P-SCAD patients more frequently presented with ST-segment elevation myocardial infarction (57% vs. 36%; p = 0.009), left main or multivessel SCAD (24% vs. 5%; p < 0.0001; and 33% vs. 14%; p = 0.0027, respectively), and left ventricular function ≤35% (26% vs. 10%; p = 0.0071). Among women with imaging of other vascular territories, P-SCAD was less likely with a diagnosis of fibromuscular dysplasia and extracoronary vascular abnormalities (42% vs. 64%; p = 0.047; and 46% vs. 77%; p = 0.0032, respectively). Compared with U.S. birth data, women with P-SCAD were more often multiparous (p = 0.0167), had a history of infertility therapies (p = 0.0004), and had pre-eclampsia (p = 0.001). On long-term follow-up (median 2.3 years) recurrent SCAD occurred in 51 patients, with no difference in the Kaplan Meier 5-year recurrence rates (10% vs. 23%; p = 0.18).

CONCLUSIONS

P-SCAD patients had more acute presentations and high-risk features than women with NP-SCAD did. The highest frequency of P-SCAD occurred during the first postpartum month and P-SCAD patients less often had extracoronary vascular abnormalities. Hormonal, hemodynamic variations, and yet-undefined mechanisms might be significant contributors to P-SCAD. (The "Virtual" Multicenter Spontaneous Coronary Artery Dissection [SCAD] Registry [SCAD]; NCT01429727; Genetic Investigations in Spontaneous Coronary Artery Dissection [SCAD]; NCT01427179).

Congenital and Acquired Valvular Heart Disease in Pregnancy

PURPOSE OF REVIEW

The number of pregnancies complicated by valvular heart disease is increasing. This review describes the hemodynamic effects of clinically important valvular abnormalities during pregnancy and reviews current guideline-driven management strategies.

RECENT FINDINGS

Valvular heart disease in women of childbearing age is most commonly caused by congenital abnormalities and rheumatic heart disease. Regurgitant lesions are well tolerated, while stenotic lesions are associated with a higher risk of pregnancy-related complications. Management of symptomatic disease during pregnancy is primarily medical, with percutaneous interventions considered for refractory symptoms. Most guidelines addressing the management of valvular heart disease during pregnancy are based on case reports and observational studies. Additional investigation is required to further advance the care of this growing patient population.

Echocardiographic Techniques of Deformation Imaging in the Evaluation of Maternal Cardiovascular System in Patients with Complicated Pregnancies

Cardiovascular diseases (CVD) represent the leading cause of maternal mortality and morbidity. Knowledge of CVD in women is constantly evolving and data are emerging that female-specific risk factors as complications of pregnancy are conditions associated with an increased risk for the long-term development of CVD. Echocardiography is a safe and effective imaging technique indicated in symptomatic or asymptomatic pregnant women with congenital heart diseases who require close monitoring of cardiac function. Deformation imaging is an echocardiographic technique used to assess myocardial function by measuring the actual deformation of the myocardium through the cardiac cycle. Speckle-tracking echocardiography (STE) is a two-dimensional (2D) technique which has been found to be more accurate than tissue Doppler to assess both left ventricular (LV) and right ventricular (RV) myocardial function. The use of 2D STE however might present some technical issues due to the tomographic nature of the technique and the motion in the three-dimensional space of the myocardial speckles. This has promoted the use of 3D STE to track the motion of the speckles in the 3D space. This review will focus on the clinical value of the new echocardiographic techniques of deformation imaging used to assess the maternal cardiovascular system in complicated pregnancies.

Pregnancy, pregnancy loss, and the risk of cardiovascular disease in Chinese women: findings from the China Kadoorie Biobank

BACKGROUND

Pregnancy and pregnancy loss may be linked to cardiovascular disease (CVD). However, the evidence is still inconsistent, especially in East Asians, whose reproductive patterns differ importantly from those in the West. We examined the associations of pregnancy, miscarriage, induced abortion, and stillbirth with CVD incidence among Chinese women.

METHODS

In 2004-2008, the nationwide China Kadoorie Biobank recruited 302,669 women aged 30-79 years from ten diverse localities. During 7 years of follow-up, 43,968 incident cases of circulatory disease, 14,440 of coronary heart disease, and 19,925 of stroke (including 11,430 ischaemic and 2170 haemorrhagic strokes), were recorded among 289,573 women without prior CVD at baseline. Cox regression yielded multiple adjusted hazard ratios (HRs) for CVD risks associated with pregnancy outcomes.

RESULTS

Overall, 99% of women had been pregnant, and among them 10%, 53%, and 7% reported having a history of miscarriage, induced abortion, and stillbirth, respectively. Each additional pregnancy was associated with an adjusted HR of 1.03 (95% confidence interval, CI: 1.02; 1.04) for circulatory disease. A history of miscarriage, induced abortion, and stillbirth, respectively, were associated with adjusted HRs of 1.04 (1.01; 1.07), 1.04 (1.02; 1.07), and 1.07 (1.03; 1.11) for circulatory disease. The relationship was stronger with recurrent pregnancy loss; adjusted HRs for each additional loss being 1.04 (1.00; 1.09) for miscarriage, 1.02 (1.01; 1.04) for induced abortion, and 1.04 (1.00; 1.08) for stillbirth.

CONCLUSIONS

Among Chinese women, increases in pregnancy, and a history and recurrence of miscarriage, induced abortion, and stillbirth are each associated with a higher risk of CVD.

MicroRNA-210 Targets Ten-Eleven Translocation Methylcytosine Dioxygenase 1 and Suppresses Pregnancy-Mediated Adaptation of Large Conductance Ca2+-Activated K+ Channel Expression and Function in Ovine Uterine Arteries

Gestational hypoxia inhibits large conductance Ca2+-activated K+ (BKCa) channel expression and function in uterine arterial adaptation to pregnancy. Given the findings that microRNA-210 (miR-210) is increased in hypoxia during gestation and preeclampsia, the present study sought to investigate the role of miR-210 in the regulation of BKCa channel adaptation in the uterine artery. Gestational hypoxia significantly increased uterine vascular resistance and blood pressure in pregnant sheep and upregulated miR-210 in uterine arteries. MiR-210 bound to ovine ten-eleven translocation methylcytosine dioxygenase 1 mRNA 3' untranslated region and decreased ten-eleven translocation methylcytosine dioxygenase 1 mRNA and protein abundance in uterine arteries of pregnant sheep, as well as abrogated steroid hormone-induced upregulation of ten-eleven translocation methylcytosine dioxygenase 1 expression in uterine arteries of nonpregnant animals. In accordance, miR-210 blocked pregnancy- and steroid hormone-induced upregulation of BKCa channel β1 subunit expression in uterine arteries. Functionally, miR-210 suppressed BKCa channel current density in uterine arterial myocytes of pregnant sheep and inhibited steroid hormone-induced increases in BKCa channel currents in uterine arteries of nonpregnant animals. Blockade of endogenous miR-210 inhibited hypoxia-induced suppression of BKCa channel activity. In addition, miR-210 decreased BKCa channel-mediated relaxations and increased pressure-dependent myogenic tone of uterine arteries. Together, the results demonstrate that miR-210 plays an important role in the downregulation of ten-eleven translocation methylcytosine dioxygenase 1 and repression of BKCa channel function in uterine arteries, revealing a novel mechanism of epigenetic regulation in the maladaptation of uterine hemodynamics in gestational hypoxia and preeclampsia.

Relation of the Number of Parity to Left Ventricular Diastolic Function in Pregnancy

Left ventricular diastolic dysfunction (LVDD) has been relatively less studied than other cardiac changes during pregnancy. Previous studies revealed a mild diastolic deterioration during pregnancy. However, these studies did not evaluate the long-term effect of parity on left ventricular diastolic function. A comprehensive study evaluating the long-term effect of parity on diastolic function is required. A total of 710 women with various number of parity were evaluated through echocardiography to reveal the status of diastolic function. Echocardiographic parameters were compared among the women by parity number and categorized accordingly: none, 0 to 4 and 4< parity (grand multiparous). In nulliparous group, 19 women (23.2%) had grade 1 LVDD, and only 2 women (2.4%) had grade 2 LVDD. In women with a parity number of 0 to 4, 209 women (38.3%) had grade 1 LVDD, and only 17 women (3.1%) had grade 2 LVDD. In grand multiparous group, only 2 women (2.4%) did not have LVDD, and 12 women (14.6%) had grade 2 LVDD. None of the subjects had grade 3 or grade 4 LVDD. According to hierarchical logistic regression analysis, any grade of LVDD and grade 2 LVDD had the highest rates at parity category of > 4 parity and that had 21 and 5.8 times higher than nulliparous group, respectively. In conclusion, according to the present study, grand multiparity but not multiparity, severely deteriorates left ventricular diastolic function. Further studies are warranted to evaluate the risk of gradual diastolic dysfunction after each pregnancy.

Provisional criteria for the diagnosis of hypertension in pregnancy using home blood pressure measurements

Most guidelines for the management of hypertension define it as a home blood pressure (HBP) value >135/85 mm Hg. However, there is no reference HBP value to diagnose hypertension in pregnant women. Therefore, in this study, we analyzed HBP measurements of pregnant women to determine whether it is appropriate to use the criteria for non-pregnant subjects for pregnant women. The participants of this study were 100 singleton pregnant women who visited our hospital between September 2013 and September 2016. We lent sphygmomanometers to the patients so they could measure their BP at home twice daily, and we measured their clinical BP when they visited the hospital. Six patients developed hypertensive disorders in pregnancy, whereas there were 63 women without hypertension or other complications that may affect BP. In the normotensive pregnant women, HBP values significantly correlated with the clinical BP values. HBP values equivalent to a clinical BP of 140/90 mm Hg, determined using the standard major axis method, were 120.8/83.5 mm Hg, 126.0/85.2 mm Hg and 136.3/89.3 mm Hg in the first, second and third trimesters, respectively. In normotensive pregnant women, HBP levels that indicate a risk of hypertensive disorder in pregnancy may be lower than 135/85 mm Hg before 28 weeks of gestation.

Cardiac hemodynamics before, during and after elective cesarean section under spinal anesthesia in low-risk women

OBJECTIVE

The aim of this study was to describe maternal central hemodynamic parameters before and during delivery as well at the early puerperium in healthy women undergoing elective cesarean section (CS) at term.

STUDY DESIGN

The noninvasive Cardiac System (NICaS, NI Medical, Petah-Tikva, Israel) is a regional impedance device that measures cardiac output (CO) and its derivatives with a good correlation with the gold standard Swan-Ganz catheter. We performed a prospective longitudinal study of healthy women with a singleton pregnancy at term. Maternal hemodynamic parameters were assessed by the NICaS at six time points: a few minutes before undergoing an elective CS, immediately after receiving spinal anesthesia, immediately after delivery of the fetus and placenta, after abdominal fascia closure, and within 24 to 36 and 48 to 72 h postpartum.

RESULT

Sixty-one consenting women were recruited during the study period (January 2015 to June 2015). Baseline (pre-CS) mean arterial pressure (MAP) was 87.7±7.9 mm Hg, baseline CO was 7.5±1.7 l per min and baseline total peripheral resistance (TPR) was 994±301 dyne × s per cm⁵. After spinal anesthesia CO significantly increased by 13%, no significant changes were observed in MAP or TPR. Immediately after delivery, a nadir for all parameters was reached: MAP and TPR were significantly reduced by 8% and 26%, respectively (comparing to pre-CS), and CO further increased by 9% (24% comparing to pre-CS). After fascia closure, partial recoveries of all parameters were observed. Twenty-four to thirty-six hours postpartum MAP returned to pre-CS values, while CO and TPR reached -9% and +11% comparing to baseline, respectively. None of the parameters differed significantly between 24 to 36 and 48 to 72 h postpartum.

CONCLUSION

Significant hemodynamic changes (reduction of TPR and increase of CO) take place at the time of delivery of fetus and placenta. Knowledge of normal hemodynamic values using a reliable noninvasive technique during various stages of pregnancy and the postpartum period is feasible, and might assist clinicians in assessing the level of patient deviation from expected cardiac performance, especially in high-risk women.

Preeclampsia and the brain: neural control of cardiovascular changes during pregnancy and neurological outcomes of preeclampsia

Preeclampsia (PE) is a form of gestational hypertension that complicates ∼5% of pregnancies worldwide. Over 70% of the fatal cases of PE are attributed to cerebral oedema, intracranial haemorrhage and eclampsia. The aetiology of PE originates from abnormal remodelling of the maternal spiral arteries, creating an ischaemic placenta that releases factors that drive the pathophysiology. An initial neurological outcome of PE is the absence of the autonomically regulated cardiovascular adaptations to pregnancy. PE patients exhibit sympathetic overactivation, in comparison with both normotensive pregnant and hypertensive non-pregnant females. Moreover, PE diminishes baroreceptor reflex sensitivity (BRS) beyond that observed in healthy pregnancy. The absence of the cardiovascular adaptations to pregnancy, combined with sympathovagal imbalance and a blunted BRS leads to life-threatening neurological outcomes. Behaviourally, the increased incidences of maternal depression, anxiety and post-traumatic stress disorder (PTSD) in PE are correlated to low fetal birth weight, intrauterine growth restriction (IUGR) and premature birth. This review addresses these neurological consequences of PE that present in the gravid female both during and after the index pregnancy.

Breastfeeding and the Risk of Maternal Cardiovascular Disease: A Prospective Study of 300 000 Chinese Women

BACKGROUND

Breastfeeding confers substantial benefits to child health and has also been associated with lower risk of maternal cardiovascular diseases (CVDs) in later life. However, the evidence on the effects of CVD is still inconsistent, especially in East Asians, in whom the frequency and duration of breastfeeding significantly differ from those in the West.

METHODS AND RESULTS

In 2004-2008, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30 to 79 years from 10 diverse regions across China. During 8 years of follow-up, 16 671 incident cases of coronary heart disease and 23 983 cases of stroke were recorded among 289 573 women without prior CVD at baseline. Cox regression yielded adjusted hazard ratios (HRs) and 95% CIs for incident CVD by breastfeeding. Overall, ≈99% of women had given birth, among whom 97% reported a history of breastfeeding, with a median duration of 12 months per child. Compared with parous women who had never breastfed, ever breastfeeding was associated with a significantly lower risk of CVD, with adjusted HRs of 0.91 (95% CI, 0.84-0.99) for coronary heart disease and 0.92 (95% CI, 0.85-0.99) for stroke. Women who had breastfed for ≥24 months had an 18% (HR, 0.82; 0.77-0.87) lower risk of coronary heart disease and a 17% (HR, 0.83; 0.79-0.87) lower risk of stroke compared with women who had never breastfed. Among women who ever breastfed, each additional 6 months of breastfeeding per child was associated with an adjusted HR of 0.96 (95% CI, 0.94-0.98) for coronary heart disease and 0.97 (95% CI, 0.96-0.98) for stroke.

CONCLUSIONS

Among Chinese women, a history of breastfeeding was associated with an ≈10% lower risk of CVD in later life and the magnitude of the inverse association was stronger among those with a longer duration of breastfeeding.

Placental Vesicles Carry Active Endothelial Nitric Oxide Synthase and Their Activity is Reduced in Preeclampsia

Supplemental Digital Content is available in the text.

Preeclampsia, a multisystem hypertensive disorder of pregnancy, is associated with increased systemic vascular resistance. Placentae from patients with preeclampsia have reduced levels of endothelial nitric oxide synthase (eNOS) and, thus, less nitric oxide (NO). Syncytiotrophoblast extracellular vesicles (STBEV), comprising microvesicles (STBMV) and exosomes, carry signals from the syncytiotrophoblast to the mother. We hypothesized that STBEV-bound eNOS (STBEV-eNOS), capable of producing NO, are released into the maternal circulation. Dual-lobe ex vivo placental perfusion and differential centrifugation was used to isolate STBEV from preeclampsia (n=8) and normal pregnancies (NP; n=11). Plasma samples of gestational age–matched preeclampsia and NP (n=6) were used to isolate circulating STBMV. STBEV expressed placental alkaline phosphatase, confirming placental origin. STBEV coexpressed eNOS, but not inducible nitric oxide synthase, confirmed using Western blot, flow cytometry, and immunodepletion. STBEV-eNOS produced NO, which was significantly inhibited by N ^G-nitro-l-arginine methyl ester (eNOS inhibitor; P<0.05) but not by N-(3-(aminomethyl) bezyl) acetamidine) (inducible nitric oxide synthase inhibitor). STBEV-eNOS catalytic activity was confirmed by visualizing eNOS dimerization. STBEV-eNOS was more abundant in uterine vein compared with peripheral blood, indicating placental origin. STBEV isolated from preeclampsia-perfused placentae had lower levels of STBEV-eNOS (STBMV; P<0.05) and overall lower NO activity (STBMV, not significant; syncytiotrophoblast extracellular exosomes, P<0.05) compared with those from NP. Circulating plasma STBMV from preeclampsia women had lower STBEV-eNOS expression compared with that from NP women (P<0.01). This is the first observation of functional eNOS expressed on STBEV from NP and preeclampsia placentae, as well as in plasma. The lower STBEV-eNOS NO production seen in preeclampsia may contribute to the decreased NO bioavailability in this disease.