Cardiovascular Physiology of Pregnancy

Effects of childbirth on podocyturia in women with normotensive, uncomplicated pregnancies

Changes in hemodynamics and blood pressure occur shortly before and after childbirth regardless of the mode of delivery. This study aimed to test the hypothesis that parturition induces a temporal increase in podocyturia monitored by podocyte-specific protein podocin mRNA expression levels (Pod-mRNA). A total of 105 urine specimens, consisting of 43 and 62 from 18 and 20 otherwise healthy women with vaginal delivery (VD) and elective cesarean delivery (ECS), respectively, were studied. Determination of urine protein and creatinine (Cr) concentrations and quantitative analyses of Pod-mRNA, nephrin mRNA (Nep-mRNA), synaptopodin mRNA (Syn-mRNA), and aquaporin 2 mRNA expression were performed using RT-PCR in pelleted urine samples. Levels of mRNA expression were corrected by urine Cr concentration. Podocyturia increased significantly, concomitant with a significantly decreased Nep:Pod-mRNA ratio (NPR) in the urine, collected immediately before or after childbirth regardless of the delivery mode compared with urine collected before commencement of labor or on postpartum day 3 or later. Podocyturia was significantly negatively correlated with NPR [correlation coefficient (r) = -0.614/-0.750 for VD/ECS women, respectively], as well as the Syn:Pod-mRNA ratio. Systolic blood pressure exceeded 140 mmHg during labor in 50% of VD women, and mean arterial pressure was significantly positively correlated with podocyturia during labor in VD women (r = 0.733). Thus parturition induces a transient increase in urine podocytes with reduced Nep- and Syn-mRNA expressions. Glomerular podocytes with reduced Nep- and Syn-mRNA levels were suggested to be likely to detach from the glomerular basement membrane around childbirth.

Circulating progenitor and angiogenic cell frequencies are abnormally static over pregnancy in women with preconception diabetes: A pilot study

Type 1 and 2 diabetes decrease the frequencies and functional capacities of circulating angiogenic cells (CAC). Diabetes also elevates gestational complications. These observations may be interrelated. We undertook pilot studies to address the hypothesis that preconception diabetes deviates known gestational increases in CACs. Cross-sectional study of type 1 diabetic, type 2 diabetic and normoglycemic pregnant women was conducted at 1^st, 2^nd, and 3^rd trimester and compared to a 6mo postpartum surrogate baseline. Circulating progenitor cells (CPC; CD34+CD45dimSSlow) and CACs (CD34+CD45dimSSlow expressing CD133 without or with KDR) were quantified by flow cytometry and by colony assay (CFU-Hill). In pregnant normoglycemic women, CD34+CD45dimSSlow cell frequency was greater in 1^st and 3^rd trimester than postpartum but frequency of these cells was static over type 1 or 2 diabetic pregnancies. Type 1 and type 2 diabetic women showed CACs variance versus normal controls. Type 1 diabetic women had more total CD34+KDR+ CACs in 1^st trimester and a higher ratio of CD133+KDR+ to total CD133+ cells in 1^st and 2^nd trimesters than control women, demonstrating an unbalance in CD133+KDR+ CACs. Type 2 diabetic women had more CD133+KDR+ CACs in 1^st trimester and fewer CD133+KDR- CACs at mid-late pregnancy than normal pregnant women. Thus, pregnancy stage-specific physiological fluctuation in CPCs (CD34+) and CACs (CD133+KDR+ and CD133+KDR-) did not occur in type 1 and type 2 diabetic women. Early outgrowth colonies were stable across normal and diabetic pregnancies. Therefore, preconception diabetes blocks the normal dynamic pattern of CAC frequencies across gestation but does not alter colony growth. The differences between diabetic and typical women were seen at specific gestational stages that may be critical for initiation of the uterine vascular pathologies characterizing diabetic gestations.

Myocardial performance index in hypertensive disorders of pregnancy: The relationship between blood pressures and angiogenic factors

OBJECTIVE

To study the association between cardiac function measured by myocardial performance index (MPI), blood pressures and angiogenic factors measured at the time of echocardiography in patients with and without hypertensive disorders of pregnancy (HDP).

METHODS

We prospectively studied 189 pregnant women and evaluated whether changes in cardiac function observed on echocardiography were correlated with higher blood pressures and whether higher blood pressures were associated with antiangiogenic proteins (soluble fms-like tyrosine kinase, sFlt1; soluble endoglin, sEng). Comprehensive echocardiograms, including measurement of MPI, were performed on all patients. sFlt1 and sEng levels were measured using enzyme-linked immunosorbent assay.

RESULTS

Overall, 189 patients were divided into tertiles based on mean arterial pressure (MAP). The MPI was worst in tertile 3 (0.50 ± 0.15) compared to tertile 1 (0.42 ± 0.10), p = 0.0004. sFlt1 (pg/ml) and sEng (ng/ml) were highest in tertile 3 compared to tertile 1: 15055.37 vs. 1623.01 and 33.06 vs. 8.15, respectively, with p-value <0.001. In crude multivariate regression analysis, MAP was positively correlated with MPI (r = 0.32, p < 0.001), GLS (r = 0.54, p < 0.001), sFlt1 (r = 0.60, p < 0.001) and sEng (r = 0.61, p < 0.001). After adjustment for confounders, these relationships persisted between MAP and MPI (r = 0.31, p = 0.0003), GLS (r = 0.46, p < 0.001), sFlt1 (r = 0.56, p < 0.001) and sEng (r = 0.58, p < 0.001).

CONCLUSION

Mean arterial pressure correlates with worsening cardiac function as measured by MPI and serum levels of angiogenic factors. Further studies are needed to evaluate whether a reduction in blood pressure will reverse changes in MPI or reduce levels of angiogenic proteins seen among women with HDP.

Parenthood and the risk of cardiovascular diseases among 0.5 million men and women: findings from the China Kadoorie Biobank

Background

Women's parity has been associated with risk of cardiovascular disease (CVD). It is unclear, however, whether it reflects biological effects of childbearing or uncontrolled socio-economic and lifestyle factors associated with childrearing. We assessed the association between number of children and incident CVD outcomes separately in women and men.

Methods

In 2004-08, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30-79 years from 10 diverse regions. During 7 years of follow-up, 24 432 incident cases of coronary heart disease (CHD) and 35 736 of stroke were recorded among 489 762 individuals without prior CVD. Multivariable Cox regression models were used to estimate sex-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for CHD and stroke associated with number of children.

Results

Overall, 98% of all participants had children and the mean number of children declined progressively from four in older participants to one or two in younger participants. Compared with childless women, women with children had an increased risk of CHD, but not of stroke [HR (95% CI): 1.14 (1.00; 1.30) and 1.03 (0.92; 1.16)]. Corresponding results for men were 1.20 (1.06; 1.35) and 1.13 (1.03; 1.24), respectively. In individuals with children, there was a log-linear association between number of children and CVD outcomes; in women, each additional child was associated with adjusted HRs of 1.02 (1.01; 1.04) for CHD and 1.02 (1.01; 1.03) for stroke, similar in magnitude to that in men [1.03 (1.01; 1.04) for CHD and 1.02 (1.01; 1.03) for stroke].

Conclusion

In Chinese adults, the association between the number of children and risk of CHD and stroke was similar between men and women, suggesting that factors associated with parenthood and childrearing are more likely to affect the risk of CVD outcomes than factors associated with childbearing.

Case Report of S1Q3T3 Electrocardiographic Abnormality in a Pregnant Asthmatic Patient During Acute Bronchospasm

Patient: Female, 33

Final Diagnosis: S1Q3T3 electrocardiographic abnormality in a pregnant asthmatic during acute bronchospasm

Symptoms: Cough • shortness of breath

Medication: —

Clinical Procedure: EKG

Specialty: Pulmonology

Salt, aldosterone and extrarenal Na+ - sensitive responses in pregnancy

Outside of pregnancy excessive salt consumption is known to be harmful being linked to increased blood pressure and cardiovascular disease. However, pregnancy represents a major change to a woman's physiology resulting in an intimate adaptation to environmental conditions. It is now becoming apparent that salt is essential for a number of these changes during pregnancy including haematological, cardiac adaptations as well as directly influencing placental development and the uteroplacental immune environment. The present review discusses the important role that salt has during normal pregnancy and evidence will also be presented to show how the placenta may act as a salt sensing organ temporarily, yet substantially regulating maternal blood pressure.

•

The placenta may function as an extrarenal regulator of maternal blood pressure.

•

Na⁺handling in pregnancy is completely different to the non-pregnant situation.

•

Na⁺may actually lower blood pressure in pregnancy affected with pre-eclampsia.

•

Aldosterone is an important regulator of placental and fetal development.

•

Na⁺ may compensate for aldosterone deficiency in pregnancy.

Dynamic left ventricular changes in patients with gestational diabetes: A speckle tracking echocardiography study

PURPOSE

The left ventricle (LV) undergoes physiologic remodeling in adaptation to the hemodynamic changes that occur in pregnancy. Speckle tracking echocardiography (STE) is a novel and reliable tool to evaluate subtle myocardial alterations that have been utilized to assess myocardial changes in patients with diabetes mellitus (DM) but not in patients with gestational DM (GDM). We seek to evaluate changes in LV function using STE in patients with GDM compared with women with normal pregnancy.

METHODS

This was a single-center retrospective cohort study. A total of 312 pregnant patients that underwent transthoracic echocardiogram (TTE) between 2009 and 2014 were screened. After excluding patients with comorbidities or insufficient data, 90 women were included. TTE from the second and third trimester for each patient were then reviewed, and STE analysis was performed.

RESULTS

Of the 90 subjects, 72 had normal pregnancies and 18 developed GDM. There was no difference in LV end-diastolic diameter (4.73 ± 0.40 versus 4.60 ± 0.56, p = 0.25), LV end-systolic diameter (3.12 ± 0.35 versus 2.91 ± 0.61, p = 0.152), or ejection fraction (62.26 ± 4.12 versus 63.50 ± 5.24, p = 0.314) between the two groups. Global longitudinal strain was lower (-19.8 ± 3.34 versus -17.2 ± 2.18, p < 0.001) in patients with GDM, while time-to-peak strain was greater (0.43 ± 0.05 versus 0.50 ± 0.06, p < 0.001). Circumferential and radial strains were preserved in both groups.

CONCLUSIONS

Although conventional TTE variables show preserved LV size and function, LV longitudinal strain suggests subclinical myocardial dysfunction in patients with GDM. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:20-27, 2017.

Parity, breastfeeding and risk of coronary heart disease: A pan-European case-cohort study

OBJECTIVE

There is uncertainty about the direction and magnitude of the associations between parity, breastfeeding and the risk of coronary heart disease (CHD). We examined the separate and combined associations of parity and breastfeeding practices with the incidence of CHD later in life among women in a large, pan-European cohort study.

METHODS

Data were used from European Prospective Investigation into Cancer and Nutrition (EPIC)-CVD, a case-cohort study nested within the EPIC prospective study of 520,000 participants from 10 countries. Information on reproductive history was available for 14,917 women, including 5138 incident cases of CHD. Using Prentice-weighted Cox regression separately for each country followed by a random-effects meta-analysis, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for CHD, after adjustment for age, study centre and several socioeconomic and biological risk factors.

RESULTS

Compared with nulliparous women, the adjusted HR was 1.19 (95% CI: 1.01-1.41) among parous women; HRs were higher among women with more children (e.g., adjusted HR: 1.95 (95% CI: 1.19-3.20) for women with five or more children). Compared with women who did not breastfeed, the adjusted HR was 0.71 (95% CI: 0.52-0.98) among women who breastfed. For childbearing women who never breastfed, the adjusted HR was 1.58 (95% CI: 1.09-2.30) compared with nulliparous women, whereas for childbearing women who breastfed, the adjusted HR was 1.19 (95% CI: 0.99-1.43).

CONCLUSION

Having more children was associated with a higher risk of CHD later in life, whereas breastfeeding was associated with a lower CHD risk. Women who both had children and breastfed did have a non-significantly higher risk of CHD.

Clustering of metabolic risk factors and adverse pregnancy outcomes: a prospective cohort study

BACKGROUND

The relative contributions of a cluster of metabolic risk factors to pregnancy complications are not fully understood. We investigated the correlation between clustering of metabolic risk factors and adverse pregnancy outcomes.

METHODS

This prospective cohort study was performed on pregnant women who sought health care during their whole gestation in a women's and children's hospital. The pregnancy outcomes were also followed. Pre-pregnancy overweight/obesity, as well as pregnancy high triglycerides, low high-density lipoprotein-cholesterol, hyperglycemia and raised blood pressure were defined as metabolic risk factors. Adverse pregnancy outcomes included preterm delivery, small/large for gestational age, preeclampsia, gestational diabetes mellitus, neonatal asphyxia and foetal demise. Stratified analyses were conducted on a total of 5535 women according to classification in each metabolic risk factor. The adjusted odds ratio (OR) for adverse pregnancy outcomes according to the number of clustering metabolic factors was calculated using the logistic regression analysis.

RESULTS

The number of metabolic risk factors and adverse pregnancy outcomes were positively correlated (P_trend  < 0.001). Compared with women without a metabolic risk factor, women with one metabolic risk factor had a risk (OR = 1.67 95%CI 1.42-1.96) of adverse pregnancy outcomes. Women with a cluster of two metabolic risk factors tended to develop more adverse pregnancy outcomes (OR = 3.32 95% CI 2.69-4.10), and the risk was much higher in women with a cluster of three or more metabolic risk factors (OR = 10.40 95%CI 7.37-14.69).

CONCLUSIONS

Pregnant women with a cluster of metabolic risk factors are more likely to have adverse pregnancy outcomes. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of alterations in blood volume with bed rest on glucose tolerance

Bed rest leads to rapid impairments in glucose tolerance. Plasma volume and thus dilution space for glucose are also reduced with bed rest, but the potential influence on glucose tolerance has not been investigated. Accordingly, the aim was to investigate whether bed rest-induced impairments in glucose tolerance are related to a concomitant reduction in plasma volume. This hypothesis was tested mechanistically by restoring plasma volume with albumin infusion after bed rest and parallel determination of glucose tolerance. Fifteen healthy volunteers (age 24 ± 3 yr, body mass index 23 ± 2 kg/m², maximal oxygen uptake 44 ± 8 ml·min^-1·kg^-1; means ± SD) completed 4 days of strict bed rest. Glucose tolerance [oral glucose tolerance test (OGTT)] and plasma and blood volumes (carbon monoxide rebreathing) were assessed before and after 3 days of bed rest. On the fourth day of bed rest, plasma volume was restored by means of an albumin infusion prior to an OGTT. Plasma volume was reduced by 9.9 ± 3.0% on bed rest day 3 and area under the curve for OGTT was augmented by 55 ± 67%. However, no association (R² = 0.09, P = 0.33) between these simultaneously occurring responses was found. While normalization of plasma volume by matched albumin administration (408 ± 104 ml) transiently decreased (P < 0.05) resting plasma glucose concentration (5.0 ± 0.4 to 4.8 ± 0.3 mmol/l), this did not restore glucose tolerance. Bed rest-induced alterations in dilution space may influence resting glucose values but do not affect area under the curve for OGTT.

Maternal Blood Lipid Profile during Pregnancy and Associations with Child Adiposity: Findings from the ROLO Study

BACKGROUND

The in-utero environment affects fetal development; it is vital to understand how maternal diet during pregnancy influences childhood body composition. While research indicates that triglycerides in hyperglycaemic women may increase birth weight, little is known about this relationship in euglycemic women. This study examines the relationship between maternal blood lipid status and infant adiposity up to 2 years of age.

METHODS

Data from 331 mother-child pairs from the ROLO longitudinal birth cohort study was analysed. Maternal dietary intakes were recorded and fasting blood lipids, leptin and HOMA were measured in early and late pregnancy and cord blood. Infant anthropometric measurements and skin-fold thicknesses were recorded at birth, 6 months and 2 years. Correlation and regression analyses were used to explore associations between maternal blood lipid status and infant adiposity.

RESULTS

All maternal blood lipids increased significantly during pregnancy. Maternal dietary fat intake was positively associated with total cholesterol levels in early pregnancy. Late pregnancy triglycerides were positively associated with birth weight (P = 0.03) while cord blood triglycerides were negatively associated with birth weight (P = 0.01). Cord HDL-C was negatively associated with infant weight at 6 months (P = 0.005). No other maternal blood lipids were associated with infant weight or adiposity up to 2 years of age.

CONCLUSION

Maternal and fetal triglycerides were associated with birth weight and cord HDL-C with weight at 6 months. Thus, maternal lipid concentrations may exert in-utero influences on infant body composition. There may be potential to modulate infant body composition through alteration of maternal diet during pregnancy.

Maternal body fluid composition in uncomplicated pregnancies and preeclampsia: a bioelectrical impedance analysis

OBJECTIVES

Body fluid composition changes during the course of pregnancy and there is evidence to suggest that these changes are different in uncomplicated pregnancies compared to hypertensive pregnancies. The aim of this study was to evaluate the changes in maternal body fluid composition during the course of an uncomplicated pregnancy and to assess differences in uncomplicated pregnancies versus hypertensive pregnancies by using a bio-impedance analysis technique.

STUDY DESIGN

Body fluid composition of each patient was assessed using a multiple frequency bioelectrical impedance analyser. Measurements were performed in 276 uncomplicated pregnancies, 34 patients with gestational hypertension, 35 with late onset preeclampsia and 11 with early onset preeclampsia. Statistical analysis was performed at nominal level α=0.05. A longitudinal linear mixed model based analysis was performed for longitudinal evolutions, and ANOVA with a post-hoc Bonferroni was used to identify differences between groups.

RESULTS

Measurements showed that total body water (TBW), intracellular (ICW) and extracellular water (ECW) and ECW/ICW significantly increase during the course of pregnancy. Late onset preeclampsia is associated with a higher TBW and ECW as compared to uncomplicated pregnancies, the ECW/ICW ratio is higher in preeclamptic patients compared to uncomplicated pregnancies and gestational hypertension, and ICW is not different between groups.

CONCLUSION

Body fluid composition changes differently during the course of uncomplicated pregnancies versus hypertensive pregnancies.

Parenthood and the risk of diabetes in men and women: a 7 year prospective study of 0.5 million individuals

AIMS/HYPOTHESIS

In women, higher parity has been associated with increased risk of diabetes later in life. It is unclear, however, whether this association is mainly due to biological effects of childbearing, or to socioeconomic and lifestyle factors associated with childrearing. We assessed the association between number of children and diabetes risk separately in women and men.

METHODS

Between 2004 and 2008, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30-79 (mean 51 years) from ten diverse regions across China. During 7 years of follow-up, 8,840 incident cases of diabetes were recorded among 463,347 participants without prior cardiovascular diseases or diabetes. Multivariable Cox regression yielded sex-specific HRs and 95% CIs for incident diabetes by number of children.

RESULTS

Overall, ∼98% of all participants had children. In women, there was a J-shaped association between number of children and risk of diabetes. Compared with women with one child, the adjusted HRs for diabetes were 1.39 (95% CI 1.11, 1.73) for childless women, 1.12 (95% CI 1.07, 1.18) for those with two children, 1.23 (95% CI 1.16, 1.31) for those with three children, and 1.32 (95% CI 1.21, 1.44) for those with four or more children. In men, there was a similar association with risk of diabetes; the corresponding HRs were 1.28 (95% CI 1.02, 1.60), 1.19 (95% CI 1.12, 1.26), 1.32 (95% CI 1.21, 1.44) and 1.41 (95% CI 1.24, 1.60), respectively. In both sexes, the findings were broadly similar in different population subgroups.

CONCLUSIONS/INTERPRETATION

The similarity between women and men in the association between number of children and risk of diabetes suggests that parenthood is most likely to affect diabetes risk through factors associated with childrearing rather than via biological effects of childbearing.

Bioimpedance cardiography in pregnancy: A longitudinal cohort study on hemodynamic pattern and outcome

Background

Pregnancy associated cardiovascular pathologies have a significant impact on outcome for mother and child. Bioimpedance cardiography may provide additional outcome-relevant information early in pregnancy and may also be used as a predictive instrument for pregnancy-associated diseases.

Methods

We performed a prospective longitudinal cohort trial in an outpatient setting and included 242 pregnant women. Cardiac output and concomitant hemodynamic data were recorded from 11^th–13^th week of gestation every 5^th week as well as at two occasions post partum employing bioimpedance cardiography.

Results

Cardiac output increased during pregnancy and peaked early in the third trimester. A higher heart rate and a decreased systemic vascular resistance were accountable for the observed changes. Women who had a pregnancy-associated disease during a previous pregnancy or developed hypertension or preeclampsia had a significantly increased cardiac output early in pregnancy. Furthermore, an effect of cardiac output on birthweight was found in healthy pregnancies and could be confirmed with multiple linear regression analysis.

Conclusions

Cardiovascular adaptation during pregnancy is characterized by distinct pattern described herein. These may be altered in women at risk for preeclampsia or reduced birthweigth. The assessment of cardiac parameters by bioimpedance cardiography could be performed at low costs without additional risks.

Preconception Counseling for Women with Congenital Heart Disease

With advances that have been made over the recent decades in transcatheter and surgical interventions, most patients with congenital heart disease (CHD) can survive into adulthood. Overall, probably half of these surviving patients are female. When these female CHD patients reach childbearing age, however, pregnancy management will be a major issue. In order to meet the demands of fetal growth, the maternal cardiovascular system starts a series of adaptations beginning in early pregnancy. These adaptations include: decreased systemic and pulmonary vascular resistances, decreased blood pressure, expansion of the blood volume, increased heart rate and increased cardiac output. For women with CHD, this hemodynamic alteration may increase the risks of adverse cardiovascular events as well as the fetal and neonatal complications. Therefore, proper risk stratification and effective counseling for women with CHD who are planning their pregnancies is an important undertaking.

KEY WORDS

Congenital heart disease; Pregnancy.

Early Recognition and Management of Maternal Sepsis

Although septic shock is rare in pregnancy, it is an important contributor to maternal mortality. A woman in the perinatal period can appear deceptively well before rapidly deteriorating to septic shock. We evaluated compliance with early goal-directed therapy before, during, and after the implementation of a standardized physician order set and interprofessional education. A retrospective study included 97 women with positive screening results for sepsis from April 2014 to January 2015. When comparing preintervention and postintervention results in women with sepsis, statistical significance was achieved for blood lactate level testing (p = .029), administering a broad-spectrum antibiotic (p = .006), repeat lactate level testing (p = .034), and administering a broad-spectrum antibiotic in women with severe sepsis and septic shock (p = .010). Education and a sepsis protocol using a multidisciplinary approach improves compliance with sepsis bundles, which are a group of interventions that, when used together, are intended to improve health outcomes.

Association of Gestational Diabetes Mellitus With Left Ventricular Structure and Function: The CARDIA Study

OBJECTIVE

Gestational diabetes mellitus (GDM) predicts incident cardiovascular disease (CVD). However, mechanisms linking GDM to CVD beyond intervening incident diabetes are not well understood. We examined the relation of GDM with echocardiographic parameters of left ventricular (LV) structure and function, which are important predictors of future CVD risk.

RESEARCH DESIGN AND METHODS

We studied 609 women (43% black) from the Coronary Artery Risk Development in Young Adults (CARDIA) study who delivered one or more births during follow-up and had echocardiograms in 1990-1991 (mean age 28.8 years) and 2010-2011.

RESULTS

During the 20-year follow-up, 965 births were reported, with GDM developing in 64 women (10.5%). In linear regression models adjusted for sociodemographic factors, BMI, physical activity, parity, smoking, use of oral contraceptives, alcohol intake, family history of coronary heart disease, systolic blood pressure, and lipid levels, women with GDM had impaired longitudinal peak strain (-15.0 vs. -15.7%, P = 0.025), circumferential peak strain (-14.8 vs. -15.6%, P = 0.028), lateral e' wave velocity (11.0 vs. 11.8 cm/s, P = 0.012), and septal e' wave velocity (8.6 vs. 9.3 cm/s, P = 0.015) in 2010-2011 and a greater 20-year increase in LV mass indexed to body surface area (14.3 vs. 6.0 g/m(2), P = 0.006) compared with women with non-GDM pregnancies. Further adjustment for incident type 2 diabetes after pregnancy did not attenuate these associations.

CONCLUSIONS

Pregnancy complicated by GDM is independently associated with increased LV mass and impaired LV relaxation and systolic function. Implementation of postpartum cardiovascular health interventions in women with a history of GDM may offer an additional opportunity to reduce future CVD risk.

Physiological Reduction in Left Ventricular Contractile Function in Healthy Postpartum Women: Potential Overlap with Peripartum Cardiomyopathy

Aims

Peripartum cardiomyopathy is a potentially life-threatening cause of heart failure, commoner in Afro-Caribbean than Caucasian women. Its diagnosis can be challenging due to physiological changes in cardiac function that also occur in healthy women during the early postpartum period. This study aimed to (i) establish the overlap between normal cardiac physiology in the immediate postpartum period and pathological changes in peripartum cardiomyopathy ii) identify any ethnicity-specific changes in cardiac function and cardiac biomarkers in healthy postpartum women.

Methods and Results

We conducted a cross-sectional study of 58 healthy postpartum women within 48 hours of delivery and 18 matched non-pregnant controls. Participants underwent cardiac assessment by echocardiography and strain analysis, including 3D echocardiography in 40 postpartum women. Results were compared with 12 retrospectively studied peripartum cardiomyopathy patients. Healthy postpartum women had significantly higher left ventricular volumes and mass, and lower ejection fraction and global longitudinal strain than non-pregnant controls. These parameters were significantly more impaired in peripartum cardiomyopathy patients but with overlapping ranges of values. Healthy postpartum women had higher levels of adrenomedullin, placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt1) compared to controls. The postpartum state, adrenomedullin, sFlt1 and the sFlt1:PlGF ratio were independent predictors of LV remodelling and function in healthy postpartum women.

Conclusion

Healthy postpartum women demonstrate several echocardiographic indicators of left ventricular remodelling and reduced function, which are associated with altered levels of angiogenic and cardiac biomarkers.

Cardiac output and related haemodynamics during pregnancy: a series of meta-analyses

OBJECTIVE

Cardiac output, a fundamental parameter of cardiovascular function, has consistently been shown to increase across healthy pregnancy; however, the time course and magnitude of adaptation remains equivocal within published literature. The aim of the present meta-analyses was to comprehensively describe the pattern of change in cardiac output during healthy pregnancy.

METHOD

A series of meta-analyses of previously published cardiac output data during healthy, singleton pregnancies was completed. PubMed and Scopus databases were searched for studies published between 1996 and 2014. Included studies reported absolute values during a predetermined gestational age (non-pregnant, late first trimester, early and late second trimester, early and late third trimester, early and late postpartum). Cardiac output was measured through echocardiography, impedance cardiography or inert gas rebreathing. Observational data were meta-analysed at each gestational age using a random-effects model. If reported, related haemodynamic variables were evaluated.

RESULTS

In total, 39 studies were eligible for inclusion, with pooled sample sizes ranging from 259 to 748. Cardiac output increased during pregnancy reaching its peak in the early third trimester, 1.5 L/min (31%) above non-pregnant values. The observed results from this study indicated a non-linear rise to this point. In the early postpartum, cardiac output had returned to non-pregnant values.

CONCLUSION

The present results suggest that cardiac output peaks in the early third trimester, following a non-linear pattern of adaptation; however, this must be confirmed using longitudinal studies. The findings provide new insight into the normal progression of cardiac output during pregnancy.

Electrocardiographic P-Wave Duration, QT Interval, T Peak to End Interval and Tp-e/QT Ratio in Pregnancy with Respect to Trimesters

BACKGROUND

P-wave duration helps to determine the risk of atrial arrhythmia, especially atrial fibrillation. QT interval, T peak to end interval (Tp-e), and Tp-e/QT ratio are electrocardiographic indices related to ventricular repolarization which are used to determine the risk of ventricular arrhythmias. We search for any alterations in electrocardiographic indices of arrhythmia in the pregnancy period with respect to trimesters.

METHODS

We enrolled 154 pregnant and 62 nonpregnant, healthy women into this cross-sectional study. Maximum and minimum P-wave durations (Pmax, Pmin), and QT intervals (QTmax, QTmin) were measured from 12 leads. QT measurements were corrected using Fridericia (QTc-Fr) and Bazett's (QTc-Bz) correction. Tp-e interval was obtained from the difference between QT interval, and QT peak interval (QTp) measured from the beginning of the QRS until the peak of the T wave. Tp-e/QT ratio was calculated using these measurements.

RESULTS

Pmax were 93.0 ± 9.1, 93.9 ± 8.9, 97.9 ± 5.6, 99.0 ± 6.1 in nonpregnant women, first, second, third trimesters of pregnancy, respectively (P = 0.001); whereas Pmin values were not significantly different. QTc-Fr max were 407.4 ± 14.2, 408.5 ± 16.1, 410.1 ± 13.1, 415.1 ± 10.1 (P = 0.007); Tp-e were 72.7 ± 6.2, 73.2 ± 6.5, 77.2 ± 8.9, 87.2 ± 9.6 (P < 0.001); and Tp-e/QT were 0.17 (0.14-0.20), 0.17 (0.14-0.20), 0.18 (0.15-0.23), 0.20 (0.16-0.25) in nonpregnant women, first, second, and third trimesters of pregnancy respectively (P < 0.001). None of the participants experienced any arrhythmic event.

CONCLUSIONS

P-wave duration is prolonged in the second trimester, and resumes a plateau thereafter. Maximum QTc interval, Tp-e interval and Tp-e/QT ratio are increased in the late pregnancy. Although these indices are altered during the course of pregnancy, they all remain in the normal ranges.

Peripartum cardiomyopathy: current management and future perspectives

Pregnancy is associated with marked physiological changes challenging the cardiovascular system. Among the more severe pregnancy associated cardiovascular complications, peripartum cardiomyopathy (PPCM) is a potentially life-threatening heart disease emerging towards the end of pregnancy or in the first postpartal months in previously healthy women. A major challenge is to distinguish the peripartum discomforts in healthy women (fatigue, shortness of breath, and oedema) from the pathological symptoms of PPCM. Moreover, pregnancy-related pathologies such as preeclampsia, myocarditis, or underlying genetic disease show overlapping symptoms with PPCM. Difficulties in diagnosis and the discrimination from other pathological conditions in pregnancy may explain why PPCM is still underestimated. Additionally, underlying pathophysiologies are poorly understood, biomarkers are scarce and treatment options in general limited. Experience in long-term prognosis and management including subsequent pregnancies is just beginning to emerge. This review focuses on novel aspects of physiological and pathophysiological changes of the maternal cardiovascular system by comparing normal conditions, hypertensive complications, genetic aspects, and infectious disease in PPCM-pregnancies. It also presents clinical and basic science data on the current state of knowledge on PPCM and brings them in context thereby highlighting promising new insights in diagnostic tools and therapeutic approaches and management.