Complex and irregular heart rate dynamics in fetuses compromised by maternal anemia as a high-risk pregnancy

Association of Maternal Anemia and Cesarean Delivery: A Systematic Review and Meta-Analysis

Anaemia during pregnancy is associated with an increased incidence of caesarean delivery (CD). This study was conducted to explore the association between CD and maternal anaemia. The PubMed/MEDLINE, Cochrane, Google, Google Scholar and ScienceDirect databases were searched for relevant studies on this topic. The assessment and review were conducted with the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument. The studies were assessed using the modified Newcastle−Ottawa quality assessment scale. Data were collected in an Excel sheet, and the ‘meta’ package of the R 4.0.3 software was used for statistical analysis. Fourteen studies that enrolled 336,128 pregnant women were included in the meta-analysis. Women with anaemia were found to be at a higher risk for CD (OR = 1.63, 95% CI = 1.23−2.17). As heterogeneity was detected in the studies, the random-effects model was used for the pooled meta-analysis (Q = 96.7, p < 0.001). In the subgroup analysis, anaemic women were found to be at higher risk for CD in studies from both low-middle-income (7) and high-income countries (7). In meta-regression analysis, none of the investigated covariates were associated with the pooled OR of CD. This evidence demonstrates with a moderate level of certainty that anaemic pregnant women are more likely to have CD than non-anaemic pregnant women.

Non-linear Methods Predominant in Fetal Heart Rate Analysis: A Systematic Review

The analysis of fetal heart rate variability has served as a scientific and diagnostic tool to quantify cardiac activity fluctuations, being good indicators of fetal well-being. Many mathematical analyses were proposed to evaluate fetal heart rate variability. We focused on non-linear analysis based on concepts of chaos, fractality, and complexity: entropies, compression, fractal analysis, and wavelets. These methods have been successfully applied in the signal processing phase and increase knowledge about cardiovascular dynamics in healthy and pathological fetuses. This review summarizes those methods and investigates how non-linear measures are related to each paper's research objectives. Of the 388 articles obtained in the PubMed/Medline database and of the 421 articles in the Web of Science database, 270 articles were included in the review after all exclusion criteria were applied. While approximate entropy is the most used method in classification papers, in signal processing, the most used non-linear method was Daubechies wavelets. The top five primary research objectives covered by the selected papers were detection of signal processing, hypoxia, maturation or gestational age, intrauterine growth restriction, and fetal distress. This review shows that non-linear indices can be used to assess numerous prenatal conditions. However, they are not yet applied in clinical practice due to some critical concerns. Some studies show that the combination of several linear and non-linear indices would be ideal for improving the analysis of the fetus's well-being. Future studies should narrow the research question so a meta-analysis could be performed, probing the indices' performance.

Anaemia is associated with an increased risk for caesarean delivery

OBJECTIVE

To investigate the association between anemia and cesarean delivery.

METHODS

A case-control study was conducted in Saad Abu-Alela Hospital in Khartoum, Sudan from March 1 to November 30, 2107. The cases were women who had cesarean delivery; women who delivered vaginally were the controls. Obstetrics history was gathered using a questionnaire.

RESULTS

There was no significant difference in age, parity, residence, job, education, and newborn gender between women who delivered by cesarean (n=130) and women who delivered vaginally (n=260). While mean (SD) of the body mass index (29.3 (5.4) kg/m² vs 26.3 (5.6) kg/m² , P<0.001) was significantly higher, hemoglobin level (103.0 (8.0) g/L vs 107.0 (8.0) g/L, P=0.001) was significantly lower in women who delivered by cesarean compared with women who delivered vaginally. In logistic regression analyses, age, gravidity, occupation, education, history of miscarriage, and newborn gender were not associated with cesarean delivery; overweight (adjusted odds ratio [AOR] 2.30, 95% confidence interval [CI] 1.24-4.26), obesity (AOR 7.17, 95% CI 3.64-14.13) and anemia (AOR 2.45, 95% CI 1.47-4. 11) were associated with cesarean delivery.

CONCLUSION

The significant association between anemia and cesarean delivery has important implications for the prevention and treatment of anemia among these women.

Hemodynamics and Perfusion in Premature Infants During Transfusion

BACKGROUND

Premature infants may require packed red blood cell transfusions, but current guidelines lack empirical evidence and vary among institutions and prescribers.

OBJECTIVE

To compare the physiological changes in cardiovascular hemodynamics and oxygen delivery between premature infants with anemia who receive packed red blood cell transfusions and premature infants without anemia.

METHODS

The study was a prospective observational cohort investigation of 75 premature infants. Comparisons among the data were made before, during, and after transfusion in infants with anemia and over time in infants in the control group. In infants with anemia, feedings were withheld 12 hours before and after transfusions.

RESULTS

Electrical cardiometry and near-infrared spectroscopy measurements in premature infants with anemia revealed changes in hemodynamic parameters not detected by standard bedside monitoring. Statistically significant changes were seen before and after transfusions in cardiac output, fractional tissue oxygen extraction, heart rate variability, heart rate complexity, and splanchnic regional tissue oxygen saturation.

CONCLUSION

Bedside monitoring of cardiovascular hemodynamics and oxygen delivery during packed red blood cell transfusion may inform individualized care for the premature infant with anemia and could be useful for the development of evidence-based practice guidelines.

Effects of Coexistence Hypertension and Type II Diabetes on Heart Rate Variability and Cardiorespiratory Fitness

Background

Type 2 diabetes Mellitus (T2DM) is associated with cardiac autonomic dysfunction, which is an independent predictor of mortality in chronic diseases. However, whether the coexistence of systemic arterial hypertension (HTN) with DMT2 alters cardiac autonomic modulation remains unknown.

Objective

To evaluate the influence of HTN on cardiac autonomic modulation and cardiorespiratory fitness in subjects with DMT2.

Methods

60 patients of both genders were evaluated and allocated to two groups: DMT2 patients (n = 32; 51 ± 7.5 years old) and DMT2 + HTN patients (n = 28; 51 ± 6.9 years old). RR intervals were obtained during rest in supine position. Linear and nonlinear indices of heart rate variability (HRV) were computed using Kubios HRV software. Pulmonary gas exchange was measured breath-by-breath, using a portable telemetric system during maximal incremental exercise testing on a cycle ergometer. Statistical analysis included Shapiro-Wilk test followed by Student’s t Test, Pearson correlation and linear regression.

Results

We found that patients in the DMT2+HTN group showed lower values of mean RR intervals (801.1 vs 871.5 ms), Shannon entropy (3 vs 3.2) and fractal dimension SD 1 (9.5 vs 14.5), when contrasted with patients in the DMT2 group. Negative correlations were found between some HRV nonlinear indices and exercise capacity indices.

Conclusion

HTN negatively affects the cardiac autonomic function in diabetic patients, who are already prone to develop autonomic dysfunction. Strategies are need to improve cardiac autonomic functionality in this population.

A history of repetitive cesarean section is a risk factor of anemia in healthy perimenopausal women: The Korea National Health and Nutrition Examination Survey 2010-2012

BACKGROUND AND OBJECTIVES

To determine whether the delivery method is associated with the rate of anemia in later life, using the data from the Korea National Health and Nutrition Examination Survey (KNHANES).

METHODS

This study used data from the KNHANES 2010-2012. Among 25,534 participants, 8,126 cases were included in this study after exclusion of males and other inappropriate data. The study population was divided into three groups according to the delivery modes: vaginal delivery (VD) only group, single cesarean delivery (SCD) group and repetitive cesarean delivery (RCD) group. The primary outcome was anemia and iron deficiency. Anemia was defined as hemoglobin <12 g/dl in accordance with the World Health Organization criteria. Iron deficiency was defined as low transferrin saturation (TSAT) or ferritin levels. Multivariate analysis was used for determination of association between the delivery modes and anemia.

RESULTS

The mean age was 53.4 years and the median time from the last delivery to the survey was 25 years. The VD only group was composed of 6,493 (79.9%) women, while 685 (8.4%) were classified as the SCD group and 948 (11.7%) were classified as a RCD group. The rates of anemia were 11.8%, 13.9%, and 19.7% in VD only group, SCD group, and RCD group, respectively. However, those groups were significantly different in many confounding factors. Therefore, to adjust those factors, multivariate analysis and subgroup analysis were followed. The odds of SCD for anemia and iron deficiency were not different from those of VD only. However, RCD was independently associated with anemia [Odds ratio(OR) 1.47, 95% Confidence interval (CI) 1.21-1.79, P <0.001] and iron deficiency (OR 1.42, 95% CI 1.21-1.67, P <0.001) compared to VD only. In the subgroup analysis, RCD was significantly associated with anemia in perimenopausal women, women with iron deficiency, those without any comorbidity and those without anemia-prone treatment.

CONCLUSION

Repetitive cesarean section may be a risk factor for future development of anemia in later life, especially in perimenopausal period. Therefore, evaluation and management of anemia in longer postpartum period should be considered for women who experience repetitive cesarean section.

Complexity Change in Cardiovascular Disease

With the fast development of wearable medical device in recent years, it becomes critical to conduct research on continuously measured physiological signals. Entropy is a key metric for quantifying the irregularity and/or complexity contained in human physiological signals. In this review, we focus on exploring how entropy changes in various physiological signals in cardiovascular diseases. Our review concludes that the direction of entropy change relies on the physiological signals under investigation. For heart rate variability and pulse index, the entropy of a healthy person is higher than that of a patient with cardiovascular diseases. For diastolic period variability and diastolic heart sound, the direction of entropy change is reversed. Our conclusion should not only give valuable guidance for further research on the application of entropy in cardiovascular diseases but also provide a foundation for using entropy to analyze the irregularity and/or complexity of physiological signals measured by wearable medical device.