Central hemodynamic assessment of normal term pregnancy

Predictors of Adverse Pregnancy Outcomes Following Traumatic Injuries

OBJECTIVE

After traumatic injury in pregnant women, providing timely and appropriate management for high-risk patients is crucial for both pregnant women and fetuses. This study aimed to identify risk factors that predict adverse pregnancy outcomes after traumatic injury.

METHODS

A retrospective cohort study including 317 pregnant patients who experienced trauma was conducted. The collected data included general demographics, injury mechanisms and adverse pregnancy outcomes. Patients were divided into two subgroups based on the absence or presence of trauma-related adverse pregnancy outcomes. Univariate and multivariate logistic regressions were conducted to estimate the associations between clinical variables and adverse pregnancy outcomes.

RESULTS

A total of 41 (12.93%) patients experienced adverse pregnancy outcomes within the first 24 h post-trauma. This study revealed that age >35 years (OR=14.995, 95% CI: 5.024-44.755, P<0.001), third trimester trauma (OR=3.878, 95% CI: 1.343-11.204, P=0.012), abdominal pain (OR=3.032, 95% CI: 1.221-7.527, P=0.017), vaginal bleeding (OR=3.226, 95% CI: 1.093-9.523, P=0.034), positive scan in focused assessment with sonography for trauma (FAST) positive (OR=8.496, 95% CI: 2.825-25.555, P<0.001), 9≤ injury severity score (ISS) <16 (OR=3.039, 95% CI: 1.046-8.835, P=0.041) and ISS≥16 (OR=5.553, 95% CI: 1.387-22.225, P=0.015) increased the probability of posttraumatic adverse pregnancy outcomes. Maternal age, gestational age at delivery, vaginal bleeding and positive FAST results were risk factors for abnormal delivery.

CONCLUSION

Advanced maternal age, third trimester, and positive FAST results should alert multidisciplinary trauma teams to closely monitor patients to prevent adverse pregnancy outcomes.

Post-partum maternal bradycardia: A case series and literature review

Background

Unlike tachyarrhythmias, which are common in pregnancy, there is a paucity of data regarding maternal bradycardias. Our objective was to describe the characteristics, associated conditions, and prognosis of women who develop bradycardia post-partum.

Method

We conducted a retrospective chart review of patients referred to the Obstetrical Medicine service at British Columbia Women's Hospital from January 2012 to May 2020 for post-partum maternal bradycardia.

Results

Twenty-four patients with post-partum bradycardia were included (age 34.2  ±  4.8 years; heart rate 40.4  ±  8.1 beats per minute; blood pressure 131/72 mm Hg). Sinus bradycardia (79.2%) was the most common rhythm. Dyspnea (29.4%) and chest pain (23.5%) were common symptoms. Mean time to resolution of bradycardia was 3.6  ±  3.8 days. Associated conditions potentially explaining the bradycardia were preeclampsia (54.1%), underlying (16.7%), medications (8.3%), and neuraxial anesthesia (8.3%).

Conclusions

Maternal bradycardia is an uncommon condition complicating the post-partum period, that is generally self-limiting, with the majority only require clinical observation.

Early-pregnancy N-terminal pro-brain natriuretic peptide level is inversely associated with hypertensive disorders of pregnancy diagnosed after 35 weeks of gestation

Hypertensive disorders of pregnancy (HDP) are among the major causes of high maternal and fetal/neonatal morbidity and mortality rates. Patients with HDP have significantly elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels at diagnosis; however, the NT-proBNP levels during early pregnancy are largely unknown. This study aimed to validate the association between HDP and NT-proBNP levels. This retrospective study evaluated 103 pregnant women who developed HDP diagnosed after 35 weeks of gestation and 667 who did not. The HDP group had significantly lower early-pregnancy NT-proBNP levels than the without HDP group. However, the two groups did not significantly differ in terms of the late-pregnancy NT-proBNP levels. After adjusting for confounding factors such as age, body mass index, parity, and blood pressure levels, high early-pregnancy NT-proBNP levels were associated with a lower HDP risk. Early-pregnancy NT-proBNP levels ≥ 60.5 pg/mL had a negative predictive value of 97.0% for ruling out HDP, with a sensitivity of 87.4% and specificity of 62.5%. In conclusion, elevated early-pregnancy NT-proBNP levels were associated with a lower HDP risk. Moreover, a cutoff point of ≥ 60.5 pg/mL for early-pregnancy NT-proBNP levels had a high negative predictive value and sensitivity for ruling out HDP. These findings can provide new clinical implications.

A Comparative Analysis of NT-proBNP Levels in Pregnant Women and the Impact of SARS-CoV-2 Infection: Influence on Birth Outcome

BACKGROUND

The cardiac biomarker NT-proBNP is released by the ventricles in response to increased cardiac wall tension, showing cardiac activity in heart failure. The primary objective of this comparative study was to analyze the variations of NT-proBNP levels among pregnant patients and to determine the potential influence of SARS-CoV-2 infection on these values. Secondly, the study focused on NT-proBNP levels and their influence on the type of birth.

METHODS

Blood samples were taken from 160 pregnant mothers in order to determine, through the solid-phase enzyme-linked immunosorbent assay (ELISA) method, the NT-proBNP concentrations from the plasma. The cohort was separated into two distinct groups based on SARS-CoV-2 diagnostic results: negative to the infection, and positive to the infection.

RESULTS

The SARS-CoV-2-positive group of patients presented with higher levels of NT-proBNP and had higher rates of cesarean sections. (4) Conclusions: Our research highlights the crucial relationship between elevated NT-proBNP values and the mode of giving birth, natural delivery or cesarean section, and also the influence of SARS-CoV-2 viral infection and this biomarker.

Maternal and neonatal complications during delivery according to passive versus active second stage in woman with medical conditions (ComPActSS)

Background

The incidence of serious complications during vaginal delivery with a passive second stage in women with medical conditions is unknown.

Methods

Our retrospective cohort study with matched groups (pairing 1 passive with 2 active second stage) included women who had a medical delivery plan from the high risk obstetric team at our center. The primary outcome was a composite of major maternal and neonatal complications.

Results

The primary outcome occurred in 50% (12/24) of women in the passive group versus 35.4% (17/48) (p = 0.24) in the active group. In the passive group, we observed a longer passive second stage of labor (28 vs. 8 min, p < 0.001), a tendency towards more assisted vaginal births (29.2% vs. 12.5%, p = 0.08), and more traumatic deliveries (16.7% vs. 0%, p = 0.012).

Conclusion

The higher proportion of complications in women who had a passive second stage should encourage physicians to make this recommendation only in selected cases.

The Management of Pregnant Trauma Patients: A Narrative Review

Trauma is the leading nonobstetric cause of maternal death and affects 1 in 12 pregnancies in the United States. Adhering to the fundamentals of the advanced trauma life support (ATLS) framework is the most important component of care in this patient population. Understanding the significant physiologic changes of pregnancy, especially with regard to the respiratory, cardiovascular, and hematologic systems, will aid in airway, breathing, and circulation components of resuscitation. In addition to trauma resuscitation, pregnant patients should undergo left uterine displacement, insertion of 2 large bore intravenous lines placed above the level of the diaphragm, careful airway management factoring in physiologic changes of pregnancy, and resuscitation with a balanced ratio of blood products. Early notification of obstetric providers, initiation of secondary assessment for obstetric complications, and fetal assessment should be undertaken as soon as possible but without interference to maternal trauma assessment and management. In general, viable fetuses are monitored by continuous fetal heart rate for at least 4 hours or more if abnormalities are detected. Moreover, fetal distress may be an early sign of maternal deterioration. When indicated, imaging studies should not be limited out of fear for fetal radiation exposure. Resuscitative hysterotomy should be considered in patients approaching 22 to 24 weeks of gestation, who arrive in cardiac arrest or present with profound hemodynamic instability due to hypovolemic shock.

A mathematical model of vascular and hemodynamics changes in early and late forms of preeclampsia

Preeclampsia-eclampsia syndrome is a leading cause of maternal mortality. The precise etiology of preeclampsia is still not well-defined and different forms exist, including early and late forms or preeclampsia, which may arise via distinctly different mechanisms. Low-dose aspirin administered at the end of the first trimester in women identified as high risk has been shown to reduce the incidence of early, but not late, preeclampsia; however, current risk factors show only fair predictive capability. There is a pressing need to develop accurate descriptions for the different forms of preeclampsia. This paper presents 1D fluid, solid, growth, and remodeling models for pregnancies complicated with early and late forms of preeclampsia. Simulations affirm a broad set of literature results that early forms of preeclampsia are characterized by elevated uterine artery pulsatility index (UA-PI) and total peripheral resistance (TPR) and lower cardiac output (CO), with modestly increased mean arterial blood pressure (MAP) in the first half of pregnancy, with elevation of TPR and MAP beginning at 20 weeks. Conversely, late forms of preeclampsia are characterized by only slightly elevated UA-PI and normal pre-term TPR, and slightly elevated MAP and CO throughout pregnancy, with increased TPR and MAP beginning after 34 weeks. Results suggest that preexisting arterial stiffness may be elevated in women that develop both early forms and late forms of preeclampsia; however, data that verify these results are lacking in the literature. Pulse wave velocity increases in early- and late-preeclampsia, coincident with increases in blood pressure; however, these increases are mainly due to the strain-stiffening response of larger arteries, rather than arterial remodeling-derived changes in material properties. These simulations affirm that early forms of preeclampsia may be associated with abnormal placentation, whereas late forms may be more closely associated with preexisting maternal cardiovascular factors; simulations also highlight several critical gaps in available data.

Successful treatment of a gravida with acute type A aortic dissection in the third trimester: A case report

RATIONALE

Acute type A aortic dissection is a rare and catastrophic complication of pregnancy with a very high mortality rate for both the mother and the fetus.

PATIENT CONCERNS

A 40-year-old female who was 31 weeks pregnant was transferred to our hospital due to "chest and back pain for 7 hours." Enhanced computed tomography (CT) of the aorta revealed a Standford A dissection, involving 3 branches of the aortic arch and the opening of the right coronary artery. The aortic root and ascending aorta were significantly widened.

DIAGNOSES

Acute type A aortic dissection.

INTERVENTIONS

After multidisciplinary discussions, we decided to perform cesarean section first and then cardiac surgery. A live male infant was delivered successfully by Obstetrician and Gynecologist. And then, we performed the Betalls procedure with the use of a mechanical 23# aortic-valve vessel for the patient. The innominate artery openings were reinforced with felt pads.

OUTCOMES

The procedure was successful. CT examination at 2 months after operation showed that the true lumen of the aorta was enlarged, and no dissection was found in the 3 branches of the aortic arch.

LESSONS

Type A aortic dissection during pregnancy is a rare event that carries a high risk of death for both mother and fetus. An optimal outcome can be achieved through early and accurate diagnosis, safe imaging techniques, timely and effective multidisciplinary discussion, and precise and individualized treatment.

Pregnancy in Patients with Pulmonary Arterial Hypertension in Light of New ESC Guidelines on Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is defined as an elevated mean pulmonary artery pressure (mPAP) of >20 mmHg together with a pulmonary arterial wedge pressure (PAWP) of ≤15 mmHg and pulmonary vascular resistance (PVR) of>2 Wood units (WU). Although the total mortality of pregnant women with PAH has decreased significantly in recent years and is reported to be around 12% in some databases, total mortality is still at an unacceptably high percentage. Moreover, some subgroups, such as patients with Eisenmenger's syndrome, have a particularly high mortality rate of up to 36%. Pregnancy in patients with PAH is contraindicated; its appearance is an indication for a planned termination. Education of patients with PAH, including counseling on effective contraception, is essential. During pregnancy, blood volume, heart rate, and cardiac output increase, while PVR and systemic vascular resistance decrease. The hemostatic balance is shifted towards hypercoagulability. Among PAH-specific drugs, the use of inhaled or intravenous prostacyclins, phosphodiesterase inhibitors, and calcium channel blockers (in patients with preserved vasoreactivity) is acceptable. Endothelin receptor antagonists and riociguat are contraindicated. Childbirth can take place through either vaginal delivery or caesarean section; similarly, neuraxial and general anesthesia have proven indications. In a situation where all pharmacological options have been used in pregnant or postpartum patients in a serious condition, veno-arterial ECMO is a useful therapeutic option. For PAH patients who want to become mothers, an option that does not endanger their lives is adoption.

Infertility, pregnancy and breastfeeding in kidney transplantation recipients: Key issues

Chronic kidney disease (CKD), especially in advanced stages, is an important cause of infertility. In CKD patients, infertility has been linked to multiple factors. The pathophysiology of infertility related to CKD is complex and forked. Correction of modifiable factors can improve fertility in both genders. In males as well as females, successful kidney transplantation offers good chances of restoration of reproductive function. In female renal allograft recipients, recovery of reproductive functions in the post-transplant period will manifest as restoration of normal menses and ovulation. Owing to this improvement, there is a significant risk of unplanned pregnancy, hence the need to discuss methods of contraception before transplantation. In kidney transplant recipients, different contraceptive options for pregnancy planning, have been used. The selection of one contraception over another is based on preference and tolerability. Pregnancy, in renal transplanted females, is associated with physiologic changes that occur in pregnant women with native kidneys. Immunosuppressive medications during pregnancy, in a recipient with a single functioning kidney, expose the mother and fetus to unwanted complications. Some immunosuppressive drugs are contraindicated during pregnancy. Immunosuppressive medications should be discussed with renal transplant recipients who are planning to breastfeed their babies. In addition to antirejection drugs, other medications should be managed accordingly, whenever pregnancy is planned.

Trauma in the Obstetric Patient

The authors provide a concise, comprehensive overview of the unique anatomic and physiologic features of pregnancy as well as modification and considerations important for the management of the pregnant trauma patient.

Evidence of Nitric Oxide Impairment During Hypertensive Pregnancies

Hypertensive disorders of pregnancy complicate up to 10% of pregnancies worldwide, and they can be classified into (1) gestational hypertension, (2) preeclampsia, (3) chronic hypertension and (4) chronic hypertension with preeclampsia. Nitric oxide (NO) plays an essential role in the haemodynamic adaptations observed during pregnancy. It has been shown that the nitric oxide pathway's dysfunction during pregnancy is associated with placental- and vascular-related diseases such as hypertensive disorders of pregnancy. This review aims to present a brief definition of hypertensive disorders of pregnancy and physiological maternal cardiovascular adaptations during pregnancy. We also detail how NO signalling is altered in the (a) systemic vasculature, (b) uterine artery/spiral arteries, (c) implantation and (d) placenta of hypertensive disorders during pregnancy. We conclude by summarizing the anti-hypertensive therapy of hypertensive disorders of pregnancy as a specific management strategy.

Perioperative Anesthetic Management of the Pregnant Patient With Congenital Heart Disease Undergoing Cardiac Intervention: A Systematic Review

Maternal congenital heart disease is increasingly prevalent, and has been associated with a significantly increased risk of maternal, obstetric, and neonatal complications. For patients with CHD who require cardiac interventions during pregnancy, there is little evidence-based guidance with regard to optimal perioperative management. The periprocedural management of pregnant patients with congenital heart disease requires extensive planning and a multidisciplinary teams-based approach. Anesthesia providers must not only be facile in the management of adult congenital heart disease, but cognizant of the normal, but significant, physiologic changes of pregnancy.

Changes in Vascular Function from Preconception to Postpartum Among Mongolian Women

Background: Pregnancy is associated with physiological changes to meet the metabolic demands of the growing fetus. To understand adverse pregnancy outcomes it is important to establish vascular changes throughout pregnancy. We examined longitudinal changes in vascular measurements from prepregnancy through postpartum. Materials and Methods: Seventy women planning to conceive in Ulaanbaatar, Mongolia enrolled in this prospective study. Within 6 months, 44 (63%) had conceived; of which 36 (82%) delivered. Ten (28%) developed complex pregnancies and were analyzed separately. Vascular measures included central systolic blood pressure (cSBP), central diastolic blood pressure (cDBP), augmentation index corrected for heart rate of 75 beats/minute (AIx-75), and pulse wave velocity (PWV). Measurements were performed at prepregnancy, second trimester (22-24 weeks), third trimester (34-36 weeks), and 2 months postpartum. Missing values (n = 0-6 per time period) were replaced by multiple imputation. A repeated measures analysis of variance analyzed changes within individual women over the four time points adjusted for age, parity, and body mass index. Results: We observed significant reductions from prepregnancy to second trimester for mean Alx-75 (17.1%-12.6%; p = 0.006) and cSBP (91.7-86.8 mmHg; p = 0.03) but not for cDBP or PWV. Both mean AIx-75 and cSBP increased in third trimester. In the postpartum, cSBP returned to prepregnancy levels, whereas AIx-75 exceeded prepregnancy levels, although this fell short of significance (p = 0.09). Similar vascular patterns were observed in women with complex pregnancies for AIx-75; however, PWV increased from the second trimester and remained higher through postpartum, although not significant. Conclusion: In Mongolian women, we observed a decrease in AIx-75 and cSBP from prepregnancy through second trimester, which resolved postpartum. These results provide an understanding of changes across pregnancies in an Asian country. Future studies should assess vascular changes across pregnancies to determine if it can predict conditions such as pre-eclampsia.

Obstetric Disorders and Critical Illness

In this article, we discuss some of the more common obstetric-related conditions that can lead to critical illness and require management in an ICU. These include the hypertensive disorders of pregnancy, postpartum hemorrhage, hemolysis, elevated liver enzymes, and low platelet syndrome, acute fatty liver of pregnancy, amniotic fluid embolism, and peripartum cardiomyopathy. We also discuss pulmonary embolism and Covid-19. Despite not being specific to obstetric patients, pulmonary embolism is a common, life-threatening diagnosis in pregnancy with particular risks and management aspects. Covid-19 does not seem to occur with higher frequency in pregnant women, but it leads to higher rates of ICU admissions and mechanical ventilation in pregnant women than in their nonpregnant peers. Its prevalence during our current global pandemic makes it important to discuss in this article. We provide a basis for critical care physicians to be engaged in informed conversations and management in a multidisciplinary manner with other relevant providers in the care of critically ill pregnant and postpartum women.

Progesterone Changes the Pregnancy-Induced Adaptation of Cardiomyocyte Kv2.1 Channels via MicroRNA-29b

The cardiovascular system adaptation occurs during pregnancy to ensure adequate maternal circulation. Progesterone (P4) is widely used in hormone therapy to support pregnancy, but little is known about its effects on maternal cardiac function. In this study, we investigated the cardiac repolarization and ion channel expression in pregnant subjects and mice models and studied the effects of P4 administrations on these pregnancy-mediated adaptations. P4 administrations shortened the prolongation of QTC intervals and action potential duration (APD) that occurred during pregnancy, which was mainly attributable to the reduction in the voltage-gated potassium (Kv) current under basal conditions. In vitro studies indicated that P4 regulated the Kv2.1 channel in a bidirectional manner. At a low dose (1 μM), P4 induced upregulation of Kv2.1 through P4 receptor, while at a higher dose (5 μM), P4 downregulated Kv2.1 by targeting microRNA-29b (miR-29b). Our data showed that P4 modulated maternal cardiac repolarization by regulating Kv2.1 channel activity during pregnancy. Kv2.1, as well as miR-29b, might be used as potential therapeutic targets for adaptations of the maternal cardiovascular system or evaluation of progesterone medication during pregnancy.

Recurrent births (multiparity) lead to permanent changes in cardiac structure

AIM

Although the effects of pregnancy on the cardiovascular system have been covered by many studies, permanent changes in the hearts of multiparous women have not been investigated. This study therefore aimed to examine the permanent structural changes in the cardiac structure of multiparous women via transthoracic echocardiography (TTE).

METHOD

This case-control study included 366 females who had given birth to 1-21 children, and 218 females with no previous deliveries. Anamnesis, physical examination, electrocardiography (ECG), TTE, and exercise stress tests were used to determine whether the cases had additional systemic pathologies. The structural cardiac parameters of all cases were recorded with TTE.

RESULTS

The study revealed that LV mass, LV mass index, left ventricular end diastolic volume (LVEDV), left ventricular end diastolic volume index (LVEDVI) were observed higher in women with five or more deliveries when compared to nulliparous women. On the other hand, ejection fraction (EF) was significantly lower in the same group. Receiver operating curve (ROC) analysis demonstrated that the prediction sensitivity for the presence of eccentric hypertrophy was 74% among women who had given >10.5 births, and its specificity was 97.8% (AUC: 0.949, 95% CI 0.905-0.993; p < 0.0001).

CONCLUSION

The results showed that women with recurrent births had increased left ventricular end diastolic volume, left ventricular total mass in myocardium and decreased EF due to increased end diastolic volume. The results also showed delivering at frequent intervals (especially the birth of 11 or more) may be one of the causes of eccentric hypertrophy, in women of the low-to-middle income countries.

A mathematical model of maternal vascular growth and remodeling and changes in maternal hemodynamics in uncomplicated pregnancy

The maternal vasculature undergoes tremendous growth and remodeling (G&R) that enables a > 15-fold increase in blood flow through the uterine vasculature from conception to term. Hemodynamic metrics (e.g., uterine artery pulsatility index, UA-PI) are useful for the prognosis of pregnancy complications; however, improved characterization of the maternal hemodynamics is necessary to improve prognosis. The goal of this paper is to develop a mathematical framework to characterize maternal vascular G&R and hemodynamics in uncomplicated human pregnancies. A validated 1D model of the human vascular tree from the literature was adapted and inlet blood flow waveforms at the ascending aorta at 4 week increments from 0 to 40 weeks of gestation were prescribed. Peripheral resistances of each terminal vessel were adjusted to achieve target flow rates and mean arterial pressure at each gestational age. Vessel growth was governed by wall shear stress (and axial lengthening in uterine vessels), and changes in vessel distensibility were related to vessel growth. Uterine artery velocity waveforms generated from this model closely resembled ultrasound results from the literature. The literature UA-PI values changed significantly across gestation, increasing in the first month of gestation, then dramatically decreasing from 4 to 20 weeks. Our results captured well the time-course of vessel geometry, material properties, and UA-PI. This 1D fluid-G&R model captured the salient hemodynamic features across a broad range of clinical reports and across gestation for uncomplicated human pregnancy. While results capture available data well, this study highlights significant gaps in available data required to better understand vascular remodeling in pregnancy.

Pregnancy as a Risk Factor of Severe COVID-19

Since first being identified in December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as an etiological agent behind Coronavirus disease 19 (COVID-19), has caused three waves of a global pandemic, with a fourth in progress. Despite its high percentage of asymptomatic and low-symptomatic courses of illness, the SARS-CoV-2 pandemic has claimed a higher death toll than the SARS-CoV and MERS-CoV epidemics because of its high infectivity when compared to the other coronaviruses. High COVID-19 mortality is associated with age and other coexisting morbidities, as well as healthcare quality. According to several studies, pregnant women are at a higher risk of severe COVID-19 infection and adverse pregnancy outcomes (caesarean delivery, pre-term birth, low birth weight, preeclampsia, ICU admission, and need for mechanical ventilation). In our review of recent literature, we focused on the effects of COVID-19 in pregnant women, emphasizing the subcellular pathophysiology of SARS-CoV-2. In this paper, we concentrate on the pathophysiology of sub-cellular changes in COVID-19 and endeavor to highlight the aspects that manifest in physiological pregnancy and potentially create a higher risk of SARS-CoV-2 infection and acute COVID-19 symptoms. Understanding how pregnancy-associated changes can cause a synergistic effect with COVID-19 may point us in the right direction for future prophylaxis and treatment for women undergoing COVID-19 during pregnancy.

A Detailed Review of Critical Care Considerations for the Pregnant Cardiac Patient

Maternal cardiovascular disease is a leading cause of maternal death worldwide and recently, maternal mortality has increased secondary to cardiovascular causes. Maternal admissions to critical care encompass 1%-2% of all critical care admissions, and although not common, the management of the critically ill pregnant patient is complex. Caring for the critically ill pregnant cardiac patient requires integration of pregnancy-associated physiologic changes, understanding pathophysiologic disease states unique to pregnancy, and a multidisciplinary approach to timing around delivery as well as antenatal and postpartum care. Herein we describe cardiorespiratory changes that occur during pregnancy and the differential diagnosis for cardiorespiratory failure in pregnancy. Cardiorespiratory diseases that are either associated or exacerbated by pregnancy are highlighted with emphasis on perturbations secondary to pregnancy and appropriate management strategies. Finally, we describe general management of the pregnant cardiac patient admitted to critical care.

Pregnancy-specific Reference Intervals for BNP and NT-pro BNP-Changes in Natriuretic Peptides Related to Pregnancy

Context

Cardiac disease is the leading cause of maternal mortality in the UK, so accurate cardiovascular diagnoses in pregnancy are essential. BNP (B-type natriuretic peptide) and NT-pro BNP (N-terminal-pro BNP) are useful clinical tools for investigating suspected peripartum cardiomyopathy but, as the pregnancy-specific reference intervals are undefined, it is uncertain how they should be interpreted in pregnant women.

Objectives

To define trimester-specific 95% reference intervals for BNP and NT-pro BNP in pregnancy.

Methods

Longitudinal study of 260 healthy pregnant women, with sampling in each trimester.

Results

The upper reference limit for NT-pro BNP was 200 pg/mL in the first and second trimesters, and 150 pg/mL in the third. Levels were significantly reduced in overweight women in the third trimester (P = .0001), which supports the partitioning of reference intervals by body mass index (BMI). The upper limit for BNP was 50 pg/mL, with no detectable trimester-related differences. Although other biomarkers (hemoglobin and platelets) fell throughout pregnancy, both natriuretic peptides were initially elevated before falling by the third trimester, suggesting that the observed changes in natriuretic peptides are driven by dynamic interplay between cardiac strain and progressive hemodilution. NT-pro BNP in the first trimester was inversely associated with neonatal birthweight at term (P = .011).

Conclusion

Cardiac biomarkers have an important role for investigating suspected disease in high-risk pregnant women, but a robust assessment of the levels expected in healthy pregnant women is an essential prerequisite to their application in clinical practice. This study has defined trimester- and BMI-specific reference intervals for NT-pro BNP and BNP, which may improve how women with suspected cardiovascular disease are investigated in pregnancy.

Aortic dissection during pregnancy and postpartum

BACKGROUND

Patients with aortic dissection during pregnancy and postpartum period exhibit a high mortality. At present, a complete overview of aortic dissection during pregnancy and postpartum period is lacking. ​Methods: This systematic review included 80 reports published from 2000 to 2020, comprising a total study population of 103 patients with aortic dissection. ​Results: We found that Stanford Type A aortic dissection was more common in prepartum cases, especially in the third trimester, while postpartum cases of aortic dissection were more common in Stanford Type B. The most common risk factor was connective tissue disease, with no other known risk factors. The mode of delivery had no significant effect on the type of postpartum aortic dissection. Reduced maternal and fetal mortality was observed when patients with Stanford Type A aortic dissection occurring after 28 gestational weeks underwent cesarean section followed by aortic replacement. Patients with Stanford Type B aortic dissection were treated mainly with medication and/or endovascular repair. ​Conclusion: Contemporary management of patients during pregnancy and within 12 weeks postpartum requires multidisciplinary cooperation and includes serial, noninvasive imaging, biomarker testing, and genetic risk profiling for aortopathy. Early diagnosis and accurate treatment are essential to reduce maternal and fetal mortality.

Pregnancy and pulmonary arterial hypertension: a case series and literature review

BACKGROUND

Despite the development of advanced therapies for pulmonary arterial hypertension, pregnancy remains contraindicated in these patients owing to high maternal and fetal morbidity and mortality. Limited data exist regarding pregnancy management and outcome in this unique patient population. We describe a series of pregnant patients diagnosed as having pulmonary arterial hypertension before or during pregnancy who delivered at a tertiary center with a comprehensive and established pulmonary vascular disease program.

OBJECTIVE

This study aimed to describe a single institution's experience and review the existing literature for pregnancy management and outcomes in patients with pulmonary arterial hypertension.

STUDY DESIGN

A review of all patients with pulmonary arterial hypertension who were admitted for delivery between 2005 and 2019 at our institution was performed. All data were extracted from the electronic health record and included patient demographics, pulmonary arterial hypertension subtype, pulmonary arterial hypertension-targeted therapies, and mode of delivery and anesthesia.

RESULTS

A total of 7 patients were identified; 5 patients had a prepartum diagnosis of pulmonary arterial hypertension, whereas 2 patients were diagnosed as having pulmonary arterial hypertension during the third trimester. All patients were started on prostacyclins and the majority were on combination pulmonary arterial hypertension-targeted therapy. The maternal mortality rate was 29%. Elective cesarean delivery was performed in more than 70% of cases, whereas 1 patient required an urgent cesarean delivery and 1 patient had a successful vaginal delivery. Most patients had epidural anesthesia. Notably, 2 patients required extracorporeal membrane oxygenation after delivery and both died. There were no cases of neonatal mortality.

CONCLUSION

Our cases series and the published literature to date show that pregnancy in pulmonary arterial hypertension remains poorly tolerated despite marked advancements in pulmonary arterial hypertension-targeted therapies and postpartum care. A multidisciplinary team approach remains essential for the management of these patients.

Pulmonary Hypertension in Pregnancy: A Review

Pulmonary hypertension (PH) is a disease, which targets the pulmonary vasculature affecting the heart and the lungs, and is characterized by a vast array of signs and symptoms. These manifestations of PH in pregnancy are highly variable and non-specific hence, it is prudent to have a very keen and high index of suspicion while evaluating these patients. This rare disease can be extremely debilitating and can be associated with a poor overall prognosis. Pregnancy in women with PH puts them at an elevated risk because the physiological changes associated with pregnancy are not well endured leading to even higher morbidity and mortality in these patients. Although there are various modalities for evaluation and workup of PH, right heart catheterization (RHC) remains the gold standard. A mean pulmonary artery pressure (PAP) of more than 20 mm of Hg is considered diagnostic. It is indeed heartening to see that in the past decade many novel therapeutic modalities have emerged and along with a better understanding of the disease process have proved to be promising in terms of reducing the adverse outcomes and preventing death in this population of patients.

Arterial function in hypertensive pregnant women. Is arterial stiffness a marker for the outcomes in pregnancy?

AIMS

Hypertension (HTN) in pregnancy is a major cause of maternal, foetal and neonatal morbimortality in both developing and developed countries. Arterial stiffness is a predictor of cardiovascular events and can be assessed through augmentation index (AIx) and pulse wave velocity (PWV). This study was intended to analyse the arterial stiffness in three categories, hypertensive pregnant women vs. healthy women (both pregnant and non-pregnant).

MAIN METHODS

Between 2018 and 2019, 150 women were prospectively included into three homogenous groups, of equal sizes (N = 50): pregnant women with HTN (group 1), pregnant women without HTN (group 2), and non-pregnant women (group 3). We assessed pregnant women 3 times (in all three trimesters) and six weeks postpartum, and the women from the control group once.

KEY FINDINGS

Significant differences (p < 0.001) of the hemodynamic and arterial stiffness parameters and of the heart rate (HR) (p = 0.006) were observed between groups 1 and 2. Women with pregnancy-induced HTN had different values of arterial function parameters long time before the first signs of high blood pressure (BP) occurred. Also, body mass index (BMI) had a deleterious effect in all patients, but especially in pregnant HTN women. Significant differences (p < 0.001) between groups 2 and 3 were observed regarding the BP and aortic PWV (PWVao) and, as well, significant differences (p < 0.05) between BMI, aortic systolic BP (p = 0.02), brachial AIx (p = 0.01) and pulse pressure (PP) (p = 0.049) values.

SIGNIFICANCE

The current study emphasizes the importance of the assessment of arterial function parameters and BMI as markers for future BP values and outcomes throughout gestation.

A Protocol for Evaluating Vital Signs and Maternal-Fetal Parameters Using High-Resolution Ultrasound in Pregnant Mice

Pregnancy is a unique physiological state in which two individuals coexist: the mother and the fetus. Disruption of maternal-fetal crosstalk leads to pregnancy and neonatal pathologies. Therefore, assessing maternal-fetal well-being is essential for understanding the physiological and pathological processes occurring during pregnancy. Herein, we provide a protocol that allows for the determination of body temperature, blood pressure, and the evaluation of uterine and umbilical arteries as well as maternal and fetal heart rate using high-resolution ultrasound in pregnant mice.

For complete details on the use and execution of this protocol, please refer to Gomez-Lopez et al. (2020).

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Assessing maternal-fetal well-being is critical for studying pregnancy in mice

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Evaluation of maternal-fetal parameters improves translational value

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High-resolution ultrasound of uterine and umbilical arteries can predict pathology

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This protocol is suitable for evaluating pregnancy disease and treatments in mice

Pregnancy-specific transcriptional changes upon endotoxin exposure in mice

Objectives Pregnant women are more susceptible to certain infections; however, this increased susceptibility is not fully understood. Herein, systems biology approaches were utilized to elucidate how pregnancy modulates tissue-specific host responses to a bacterial product, endotoxin. Methods Pregnant and non-pregnant mice were injected with endotoxin or saline on 16.5 days post coitum (n=8-11 per group). The uterus, cervix, liver, adrenal gland, kidney, lung, and brain were collected 12 h after injection and transcriptomes were measured using microarrays. Heatmaps and principal component analysis were used for visualization. Differentially expressed genes between groups were assessed using linear models that included interaction terms to determine whether the effect of infection differed with pregnancy status. Pathway analysis was conducted to interpret gene expression changes. Results We report herein a multi-organ atlas of the transcript perturbations in pregnant and non-pregnant mice in response to endotoxin. Pregnancy strongly modified the host responses to endotoxin in the uterus, cervix, and liver. In contrast, pregnancy had a milder effect on the host response to endotoxin in the adrenal gland, lung, and kidney. However, pregnancy did not drastically affect the host response to endotoxin in the brain. Conclusions Pregnancy imprints organ-specific host immune responses upon endotoxin exposure. These findings provide insight into the host-response against microbes during pregnancy.

Hemodynamic Complications in Pregnancy: Preeclampsia and Beyond

Normal pregnancy is a complex and dynamic process that requires significant adaptation from the maternal system. Failure of this adaptive process in pregnancy contributes to many pregnancy related disorders, including the hypertensive disorders of pregnancy. This article discusses placental development and how abnormalities in the process of vascular remodeling contribute to the multisystem maternal and fetal disease that is preeclampsia and fetal growth restriction. We review some of the consequences of this condition on the mother and fetus, aspects of the clinical management of preeclampsia and how it can influence both mother and infant in the postnatal period and beyond.

The Balance between the Safety of Mother, Fetus, and Newborn Undergoing Cystic Fibrosis Transmembrane Conductance Regulator Treatments during Pregnancy

The recent development of modulators of cystic fibrosis transmembrane conductance regulator (CFTR) has allowed the life expectancy of cystic fibrosis patients to increase substantially resulting in more women with cystic fibrosis reaching child-bearing age. This however raises the issue of whether long-term use of CFTR modulators during pregnancy and breastfeeding is safe for the fetus and newborn, especially for their developing brain. A very limited number of case reports available so far has shown that the fetus or breastfed newborn is likely to be exposed to maternally administered CFTR modulators. Potential impacts of drug exposure on the developing brain are of particular importance as the consequences might not be immediately noticeable upon birth but may manifest later in life as permanent neurobehavioral problems. In order for drugs in maternal circulation to enter the fetal brain, they must overcome the placental barrier followed by a series of brain barriers, each consisting of cellular components and physiological mechanisms such as efflux transporters. The extent of protection they offer during development will provide valuable insights into the potential entry and the effects of CFTR modulators in the developing brain. This review aims to explore the current understanding of the safety of CFTR modulators, especially ivacaftor, during pregnancy and breastfeeding, characterize the pharmacokinetics and pharmacodynamics of ivacaftor, both under normal conditions and during pregnancy, to provide context for its potential impact on the developing brain. Finally, we discuss the determinants that need to be taken into consideration when investigating the entry of drugs into the fetus and newborn.

The Effect of Exercise Training During Pregnancy to Improve Maternal Vascular Health: Focus on Gestational Hypertensive Disorders

Hypertensive disorders of pregnancy, including gestational hypertension and pre-eclampsia, occur in up to 10% of pregnancies and are associated with increased life-long cardiovascular risk. Physical activity improves cardiovascular health in pregnancy and may lower the risk of developing hypertensive disorders of pregnancy. However, a minority of pregnant women comply with the recommended level of physical activity. Adequate knowledge on the physiological effects of exercise in healthy pregnancy could help to overcome potential barriers as pregnancy is a unique window of opportunity to improve health outcomes for both mother and child. In this mini review, we discuss structural and functional vascular adaptations during healthy and hypertensive pregnancies, we elaborate on the effects of exercise on the vasculature and review the safety and existing evidence of exercise training as preventive therapy for gestational hypertensive disorders.

Nonobstetric Surgery During Pregnancy

One percent to 2% of pregnant women undergo nonobstetric surgery during pregnancy. Historically, there has been a reluctance to operate on pregnant women based on concerns for teratogenesis, pregnancy loss, or preterm birth. However, a careful review of published data suggests four major flaws affecting much of the available literature. Many studies contain outcomes data from past years in which diagnostic testing, surgical technique, and perioperative maternal-fetal care were so different from current experience as to make these data of limited utility today. This issue is further compounded by a tendency to combine experience from vastly disparate types of surgery into a single report. In addition, reports in nonobstetric journals often focus on maternal outcomes and contain insufficient detail regarding perinatal outcomes to allow distinction between complications associated with surgical disease and those attributable to surgery itself. Finally, most series are either uncontrolled or use the general population of pregnant women as controls rather than women with surgical disease who are managed nonsurgically. Consideration of these factors as well as our own extensive experience suggests that when the risks of maternal hypotension or hypoxia are minimal, or can be adequately mitigated, indicated surgery during any trimester does not appear to subject either the mother or fetus to risks significantly beyond those associated with the disease itself or the complications of surgery in nonpregnant individuals. In some cases, reluctance to operate during pregnancy becomes a self-fulfilling prophecy in which delay in surgery contributes to adverse perinatal outcomes traditionally attributed to surgery itself.

Pulse Pressure and Carotid Artery Doppler Velocimetry as Indicators of Maternal Volume Status: A Prospective Cohort Study

BACKGROUND

Narrow pulse pressure has been demonstrated to indicate low central volume status. In critically ill patients, volume status can be qualitatively evaluated using Doppler velocimetry to assess hemodynamic changes in the carotid artery in response to autotransfusion with passive leg raise (PLR). Neither parameter has been prospectively evaluated in an obstetric population. The objective of this study was to determine if pulse pressure could predict the response to autotransfusion using carotid artery Doppler in healthy intrapartum women. We hypothesized that the carotid artery Doppler response to PLR would be greater in women with a narrow pulse pressure, indicating relative hypovolemia.

METHODS

Intrapartum women with singleton gestations ≥35 weeks without acute or chronic medical conditions were recruited to this prospective cohort study. Participants were grouped by admission pulse pressure as <45 mm Hg (narrow) or ≥50 mm Hg (normal). Maternal carotid artery Doppler assessment was then performed in all patients before and after PLR using a standard technique where carotid blood flow (mL/min) = π × (carotid artery diameter/2) × (velocity time integral) × (60 seconds). The velocity time integral was calculated from the Doppler waveform. The primary outcome was the change in the carotid Doppler parameters (carotid artery diameter, velocity time integral, and carotid blood flow) after PLR. Outcomes were compared between study groups with univariable and multivariable analyses with adjustment for potential confounding factors.

RESULTS

Thirty-three women consented to participation, including 18 in the narrow and 15 in the normal pulse pressure groups (mean and standard deviation initial pulse pressure, 38.3 ± 4.4 vs 57.3 ± 4.1 mm Hg). The 2 groups demonstrated similar characteristics except for initial pulse pressure, systolic and diastolic blood pressure, and race. In response to PLR, the narrow pulse pressure group had a significantly greater increase in carotid artery diameter (0.08 vs 0.02 cm; standardized difference, 2.0; 95% confidence interval [CI], 1.16-2.84), carotid blood flow (79.4 vs 16.0 mL/min; standardized difference, 2.23; 95% CI, 1.36-3.10), and percent change in carotid blood flow (47.5% vs 8.7%; standardized difference, 2.52; 95% CI, 1.60-3.43) compared with the normal pulse pressure group. In multivariable analysis with adjustment for potential confounding factors, women with narrow admission pulse pressure had a significantly larger carotid diameter (0.66 vs 0.62 cm; P < .0001) and greater carotid flow (246.7 vs 219.3 cm/s; P = .001) after PLR compared to women with a normal pulse pressure. Initial pulse pressure was strongly correlated with the change in carotid flow after PLR (r = 0.60; P < .0001).

CONCLUSIONS

The hemodynamic response of the carotid artery to autotransfusion after PLR is significantly greater in women with narrow pulse pressure. Pulse pressure correlates with the physiological response to autotransfusion and provides a qualitative indication of intravascular volume in term and near-term pregnant women.

Cardiac output measurements during high-risk Cesarean section using electrical bioreactance or arterial waveform analysis: assessment of agreement

OBJECTIVE

Maternal hemodynamics change significantly during Cesarean section complicated by massive hemorrhage or severe hypertensive disease. Cardiac output (CO) monitoring aids early, goal-directed hemodynamic therapy. The aim of this study was to record hemodynamic changes observed during Cesarean section in pregnancies at high risk of hemodynamic instability, using invasive (LiDCOrapid™) and non-invasive (NICOM®) devices, and to assess agreement between the two devices in measuring CO.

METHODS

Simultaneous intraoperative hemodynamic measurements were taken using the LiDCOrapid and NICOM devices, following standardized techniques, in women at high risk of hemodynamic instability undergoing Cesarean section. Agreement in CO measurements between the two devices was assessed using Bland-Altman plots and the agreement:tolerability index (ATI). Agreement analyses were performed for repeated measures in subjects, using centiles.

RESULTS

From 10 women, 307 paired measurements were analyzed. Mean bias (defined as the mean difference in CO measurements between the LiDCOrapid and NICOM devices) was 3.05 (95% CI, 1.89 to 4.21) L/min. Limits of agreement ranged from -1.58 (95% CI, -4.47 to -0.14) to 7.68 (95% CI, 6.24 to 10.56) L/min. The resulting agreement interval was 9.26 L/min which returned an ATI of 2.3.

CONCLUSIONS

There are large mean differences between CO measurements obtained during Cesarean section using the LiDCOrapid and NICOM hemodynamic monitors in pregnant women at high risk of hemodynamic instability, indicating that they should not be considered interchangeable clinically. There is an unacceptably low level of agreement (ATI > 2) in CO measurements between the devices, conferring a high risk of clinical misclassification during massive hemorrhage. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Physiologic and Hemodynamic Changes During Pregnancy

Substantial physiologic changes accompany pregnancy, the most profound of which involve the cardiovascular system. These changes affect maternal hemodynamic and oxygen transport status. This article describes cardiovascular changes that occur during pregnancy including blood volume, heart rate, stroke volume, cardiac output, vascular resistance, and colloid osmotic pressure. Alterations in factors related to maternal oxygen transport including oxygen affinity, delivery, and consumption also are described. Concepts related to fetal oxygen transport and adaptive responses to hypoxemia are presented. Technical considerations regarding assessment of maternal hemodynamic and oxygen transport status during pregnancy are described and assessment findings during labor, birth, and the immediate postpartum period are interpreted. A maternal hemodynamic and oxygen transport profile is presented to illustrate these principles in clinical practice.

Pulmonary Edema in Obstetrics: Essential Facts for Critical Care Nurses

Pulmonary edema is an acute pregnancy complication that, if uncorrected, can result in increased maternal and fetal morbidity and mortality. Although pulmonary edema is relatively rare in the general obstetrics population, pregnant patients are at increased risk for pulmonary edema because of the physiologic changes of pregnancy. The risk may be exacerbated by certain pregnancy-related diseases, such as preeclampsia. Prompt identification and appropriate clinical management of pulmonary complications is critical to prevent adverse outcomes in pregnant patients. This article reviews the collaborative treatment of pulmonary edema in pregnant women with complex critical illnesses.

Recognition and Management of Sepsis in the Obstetric Patient

Sepsis is one of the principal causes of maternal mortality in obstetrics. Physiologic changes that occur during pregnancy create a vulnerable environment, predisposing pregnant patients to the development of sepsis. Furthermore, these changes can mask sepsis indicators normally seen in the nonobstetric population, making it difficult to recognize and treat sepsis in a timely manner. The use of maternal-specific early warning tools for sepsis identification and knowledge of appropriate interventions and their effects on the mother and fetus can help clinicians obtain the best patient outcomes in acute care settings. This article outlines the signs and symptoms of sepsis in obstetric patients and discusses treatment options used in critical care settings.

Maternal functional hemodynamics in uncomplicated twin pregnancies: A longitudinal study using impedance cardiography

INTRODUCTION

Longitudinal studies of maternal hemodynamics in twin pregnancy are scarce and preload reserve in twin pregnancies has not been studied. Thus, we aimed to investigate serial changes in maternal systemic hemodynamics from the first to third trimester, and cardiovascular response to passive leg raising to evaluate preload reserve using impedance cardiography in a cohort of uncomplicated twin pregnancies.

MATERIAL AND METHODS

This was a prospective longitudinal study of 50 twin pregnancies. Maternal hemodynamics was assessed at baseline and 120 seconds after passive leg raising using impedance cardiography, at five time points during gestation. Women were excluded from the analysis if there were pregnancy complications or fewer than three of five planned assessments were available.

RESULTS

Data from 37 uncomplicated twin pregnancies were available for analysis. Mean arterial pressure slightly decreased until 17 weeks' gestation, then increased. Systemic vascular resistance was constant in the first half of pregnancy before rising steadily thereafter, whereas the cardiac output increased from the first trimester, peaked by the end of the second trimester and then decreased in the third trimester. The change in stroke volume and cardiac output following passive leg raising during pregnancy ranged from -2.2% to 1.6% and from -3.7% to 3.2%, respectively. Although passive leg raising caused no significant changes in systemic vascular resistance, cardiac output or heart rate, mean arterial pressure decreased in the first and second trimesters.

CONCLUSIONS

In uncomplicated twin pregnancies, maternal cardiovascular adaptation is evident from the first trimester. Twin pregnancies show a reduced preload reserve in the second half of gestation.

Does left ventricular hypertrophy by electrocardiogram predict adverse outcomes in pregnancies with chronic hypertension?

Objectives: The American College of Obstetricians and Gynecologists Task Force on Hypertension in Pregnancy recommends assessing left ventricular function with echocardiogram or electrocardiogram (ECG) in women with severe hypertension of long duration. We aim to compare the rates of superimposed preeclampsia (SIP) and other obstetrical outcomes in pregnancies with chronic hypertension (CHTN) and left ventricular hypertrophy (LVH) by ECG criteria with mothers without LVH.Study design: After IRB approval, we performed a retrospective chart review from January 2015 to December 2016. Singleton pregnancies with CHTN who carried the pregnancy beyond 20 weeks and planned to deliver at our institution were included for analysis. Patients with insufficient data, multiple gestations, and those with systemic lupus erythematosus were excluded from this study. Rates of SIP and other obstetrical outcomes were compared among those with LVH and those without LVH. Univariate parametric and nonparametric statistical models were applied as appropriate. Associations were considered statistically significant at an alpha level of 0.05.Results: We included 218 pregnancies. Nineteen (8.7%) had LVH. The rate of SIP was higher in pregnancies with LVH than in those without it (68 versus 41%; OR = 3.01; 95% CI 1.1-8.5; p = .022). The birthweight was lower in the LVH group (2432 g [2120-2990] versus 2870 g [2430-3440]; p = .016). Other obstetrical outcomes were not significantly different between those patients with LVH and those without.Conclusions: LVH by ECG criteria may be associated with higher rates of SIP and with lower birthweight in pregnancies with CHTN. ECG may be a cost-effective tool to identify patients with CHTN at risk of adverse outcomes. Larger trials are necessary to corroborate our findings.

Partial amniotic carbon dioxide insufflation for fetal surgery

Partial amniotic carbon dioxide insufflation (PACI) involves insufflating the amniotic sac with carbon dioxide (CO₂ ) and, in some cases, draining some of the amniotic fluid. The creation of a gaseous intra-amniotic compartment improves visualization, even in the presence of limited bleeding, and creates the work space required for complex fetoscopic procedures. Clinically, PACI is mostly used to perform fetoscopic myelomeningocele (MMC) repair, enabling a minimally invasive alternative to open fetal surgery. However, evidence of the fetal safety of PACI is limited. Previous animal experiments in sheep demonstrate that PACI induces fetal hypercapnia and acidosis with largely unknown short and longer term implications. In this review, we examine the literature for the physiological effects of intrauterine insufflation pressure, duration, humidity, and the role of maternal hyperventilation on fetal physiology and well-being.

Symptomatic Subclavian Steal During Pregnancy in a Woman Status Post Coarctation Repair in Infancy

A 24-year-old woman with a history of coarctation repair by subclavian flap aortoplasty presented at 15 weeks' gestation with transient episodes of vision loss. She was diagnosed with subclavian steal syndrome and underwent left carotid artery to subclavian artery bypass at 17 weeks' gestation. She has had no recurrence of symptoms at ten months of postoperative follow-up. Despite the anatomic substrate for subclavian steal in patients with this type of surgical repair, neurologic symptoms are uncommon. It is possible that the pregnancy-induced fall in systemic vascular resistance triggered symptoms in this previously asymptomatic patient.

Regulators of G protein signaling in cardiovascular function during pregnancy

G protein-coupled receptor signaling mechanisms are implicated in many aspects of cardiovascular control, and dysfunction of such signaling mechanisms is commonly associated with disease states. Investigators have identified a large number of regulator of G protein signaling (RGS) proteins that variously contribute to the modulation of intracellular second-messenger signaling kinetics. These many RGS proteins each interact with a specific set of second-messenger cascades and receptor types and exhibit tissue-specific expression patterns. Increasing evidence supports the contribution of RGS proteins, or their loss, in the pathogenesis of cardiovascular dysfunctions. This review summarizes the current understanding of the functional contributions of RGS proteins, particularly within the B/R4 family, in cardiovascular disorders of pregnancy including gestational hypertension, uterine artery dysfunction, and preeclampsia.

Maternal cardiovascular hemodynamics in normotensive versus preeclamptic pregnancies: a prospective longitudinal study using a noninvasive cardiac system (NICaS™)

BACKGROUND

Preeclampsia is among the most common medical complications of pregnancy. The clinical utility of invasive hemodynamic monitoring in preeclampsia (e.g., Swan-Ganz catheter) is controversial. Thoracic impedance cardiography (TIC) and Doppler echocardiography are noninvasive techniques but they both have important limitations. NICaS™ (NI Medical, PetachTikva, Israel) is a noninvasive cardiac system for determining cardiac output (CO) that utilizes regional impedance cardiography (RIC) by noninvasively measuring the impedance signal in the periphery. It outperformed any other impedance cardiographic technology and was twice as accurate as TIC.

METHODS

We used the NICaS™ system to compare the hemodynamic parameters of women with severe preeclampsia (PET group, n = 17) to a cohort of healthy normotensive pregnant women with a singleton pregnancy at term (control group, n = 62) (1/2015-6/2015). Heart rate (HR), stroke volume (SV), CO, total peripheral resistance (TPR) and mean arterial pressure (MAP) were measured 15-30 min before CS initiation, immediately after administering spinal anesthesia, immediately after delivery of the fetus and placenta, at the abdominal fascia closure and within 24-36 and 48-72 h postpartum.

RESULTS

The COs before and during the CS were significantly higher in the control group compared to the PET group (P < .05), but reached equivalent values within 24-36 h postpartum. CO peaked at delivery of the newborn and the placenta and started to decline afterwards in both groups. The MAP and TPR values were significantly higher in the PET group at all points of assessment except at 48-72 h postpartum when it was still significantly higher for MAP while the TPR only exhibited a higher trend but not statistically significant. The NICaS™ device noninvasively demonstrated low CO and high TPR profiles in the PET group compared to controls.

CONCLUSIONS

The immediate postpartum period is accompanied by the most dramatic hemodynamic changes and fluid shifts, during which the parturient should be closely monitored. The NICaS™ device may help the clinician to customize the most optimal management for individual parturients. Our findings require validation by further studies on larger samples.