A population-based study of preeclampsia and eclampsia in Ecuador: ethnic, geographical and altitudes differences

Clinical manifestations and complications of preeclampsia and eclampsia in populations residing at high altitudes and very high altitudes: A scoping review

INTRODUCTION

Preeclampsia and eclampsia are conditions that affect gestation, characterized by high blood pressure and direct organ damage, while geographical altitude directly affects cardiovascular physiology. The aim of this review is to identify the clinical manifestations and complications of preeclampsia in pregnant women at high and very high altitudes.

METHODS

A scoping review was conducted to assess the objective. A systematic search was performed on Pubmed, Web of Science, Embase, Scopus, Scielo, and Lilacs. Studies including pregnant women with preeclampsia or eclampsia at high altitudes and very high altitudes were included, excluding non-citable documents. Results were summarized in tables based on bibliographic data, methodological aspects, and key findings.

RESULTS

Eight documents meeting the inclusion and exclusion criteria were obtained. Seven studies focused on populations in Latin America, with the highest geographical altitude being 4380 m above sea level in the city of Cerro de Pasco, Peru. One report suggests a higher admission rate to the Intensive Care Unit and a higher frequency of HELLP syndrome. Functional cardiovascular changes were also observed.

CONCLUSIONS

There are few studies directly evaluating pregnant populations at high altitudes and very high altitudes experiencing preeclampsia and eclampsia. Complications may be more frequent at high altitudes and very high altitudes with clinically unobservable cardiovascular changes.

Exposure to a Low-Oxygen Environment Causes Implantation Failure and Transcriptomic Shifts in Mouse Uteruses and Ovaries

Hypoxia is a condition in which tissues of the body do not receive sufficient amounts of oxygen supply. Numerous studies have elucidated the intricate roles of hypoxia and its involvement in both physiological and pathological conditions. This study aimed to clarify the impact of a forced low-oxygen environment in early pregnancy by exposing mice to low-oxygen conditions for 24-72 h after fertilization. The treatment resulted in the complete failure of blastocyst implantation, accompanied by vascular hyperpermeability in the uterus. A transcriptome analysis of the uterus revealed remarkable alterations in gene expression between control normoxic- and hypoxic-treatment groups. These alterations were characterized by the differentially expressed genes categorized into the immune responses and iron coordination. Furthermore, exposure to a low-oxygen environment caused apoptosis in the corpus luteum within the ovary and a reduction in progesterone secretion. Consequently, diminished plasma progesterone levels were considered to contribute to implantation failure in combination with the activation of the hypoxic pathway in the uterus. Additionally, previous studies have demonstrated the impact of hypoxic reactions on blastocyst development and the pre-implantation process in the endometrium. Our findings suggest that the corpus luteum exhibits elevated susceptibility to hypoxia, thereby elucidating a critical aspect of its physiological response.

Genetic Appraisal of RAAS-Associated SNPs: REN (rs16853055), AGT (rs3789678) and ACE (rs4305) in Preeclamptic Women Living with HIV Infection

PURPOSE OF REVIEW

The primary goal of this review article was to determine whether the three RAAS-associated SNPs, Renin-rs16853055, AGT-rs3789678 and ACE-rs4305 are genetically linked to the development of hypertension in preeclampsia. The secondary goal was to establish if there was a link between these SNPs and HIV infection.

RECENT FINDINGS

There is a paucity of findings related to the aforementioned SNPs and preeclampsia. There are no recent findings on the rs16853055 renin polymorphism. The rs3789678 angiotensinogen polymorphism correlated significantly with gestational hypertension. The rs4305 ACE polymorphism showed no significant association with the development of pregnancy-induced hypertension. There are conflicting findings when determining the relationship between ethnicity and the predisposition of preeclampsia and hypertension in relation to the discussed RAAS-associated SNPs. To date, the association between RAAS-associated SNPs and preeclamptic women co-morbid with HIV in South Africa has revealed that certain alleles of the AGT gene are more prominent in HIV-infected PE compared to normotensive pregnant HIV-infected women.

Single-cell RNA-seq reveals developmental deficiencies in both the placentation and the decidualization in women with late-onset preeclampsia

Preeclampsia (PE) is a leading cause of maternal and fetal morbidity and mortality. Although increasing lines of evidence suggest that both the placenta and the decidua likely play roles in the pathogenesis of PE, the molecular mechanism of PE remains elusive partly because of the heterogeneity nature of the maternal-fetal interface. In this study, we perform single-cell RNA-seq on the placenta and the decidual from patients with late-onset PE (LOPE) and women in normal pregnancy. Analyses of single-cell transcriptomes reveal that in LOPE, there are likely a global development deficiency of trophoblasts with impaired invasion of extravillous trophoblasts (EVT) and increased maternal immune rejection and inflammation in the placenta, while there are likely insufficient decidualization of decidual stromal cells (DSC), increased inflammation, and suppressed regulatory functions of decidual immune cells. These findings improve our understanding of the molecular mechanisms of PE.

Effect of High Altitude on the Survival of COVID-19 Patients in Intensive Care Unit: A Cohort Study

Purpose: The effect of high altitude ( ≥ 1500 m) and its potential association with mortality by COVID-19 remains controversial. We assessed the effect of high altitude on the survival/discharge of COVID-19 patients requiring intensive care unit (ICU) admission for mechanical ventilation compared to individuals treated at sea level. Methods: A retrospective cohort multi-center study of consecutive adults patients with a positive RT-PCR test for COVID-19 who were mechanically ventilated between March and November 2020. Data were collected from two sea-level hospitals and four high-altitude hospitals in Ecuador. The primary outcome was ICU and hospital survival/discharge. Survival analysis was conducted using semi-parametric Cox proportional hazards models. Results: Of the study population (n = 670), 35.2% were female with a mean age of 58.3 ± 12.6 years. On admission, high-altitude patients were more likely to be younger (57.2 vs. 60.5 years old), presented with less comorbidities such as hypertension (25.9% vs. 54.9% with p-value <.001) and diabetes mellitus (20.5% vs. 37.2% with p-value <.001), less probability of having a capillary refill time > 3 sec (13.7% vs. 30.1%, p-value <.001), and less severity-of-illness condition (APACHE II score, 17.5 ± 8.1 vs. 20 ± 8.2, p < .01). After adjusting for key confounders high altitude is associated with significant higher probabilities of ICU survival/discharge (HR: 1.74 [95% CI: 1.46-2.08]) and hospital survival/discharge (HR: 1.35 [95% CI: 1.18-1.55]) than patients treated at sea level. Conclusions: Patients treated at high altitude at any time point during the study period were 74% more likely to experience ICU survival/discharge and 35% more likely to experience hospital survival/discharge than to the sea-level group. Possible reasons for these findings are genetic and physiological adaptations due to exposure to chronic hypoxia.

ACOG and local diagnostic criteria for hypertensive disorders of pregnancy (HDP) in La Paz-El Alto, Bolivia: A retrospective case-control study

Background

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal death in low- to middle-income countries (LMIC). The American College of Obstetricians and Gynecologists (ACOG) updated diagnostic guidelines to align signs and symptoms with those associated with maternal death. We performed an observational study to ask whether ACOG guidelines were employed and associated with adverse outcomes in La Paz-El Alto, Bolivia, an LMIC.

Methods

Medical records for all HDP discharge diagnoses (n = 734) and twice as many controls (n = 1647) were reviewed for one year at the three largest delivery sites. For the 690 cases and 1548 controls meeting inclusion criteria (singleton, 18-45 maternal age, local residence), health history, blood pressures, symptoms, lab tests, HDP diagnoses (i.e., gestational hypertension [GH]; preeclampsia [PE]; haemolysis, low platelets, high liver enzymes [HELLP] syndrome, eclampsia), and adverse outcomes were recorded. Bolivian diagnoses were compared to ACOG guidelines using accuracy analysis and associated with adverse outcomes by logistic regression.

Findings

Both systems agreed with respect to eclampsia, but only 27% of all Bolivian HDP diagnoses met ACOG criteria. HDP increased adverse maternal- or perinatal-outcome risks for both systems, but ACOG guidelines enabled more pre-delivery diagnoses, graded maternal-risk assessment, and targeting of HDP terminating in maternal death.

Interpretation

Bolivia diagnoses agreed with ACOG guidelines concerning end-stage disease (eclampsia) but not the other HDP due mainly to ACOG's recognition of a broader range of severe features. ACOG guidelines can aid in identifying pregnancies at greatest risk in LMICs, where most maternal and perinatal deaths occur.

Funding

NIH TW010797, HD088590, HL138181, UL1 TR002535.

High Altitude Pregnancies and Vascular Dysfunction: Observations From Latin American Studies

An estimated human population of 170 million inhabit at high-altitude (HA, above 2,500 m). The potential pathological effects of HA hypobaric hypoxia during gestation have been the focus of several researchers around the world. The studies based on the Himalayan and Central/South American mountains are particularly interesting as these areas account for nearly 70% of the HA world population. At present, studies in human and animal models revealed important alterations in fetal development and growth at HA. Moreover, vascular responses to chronic hypobaria in the pregnant mother and her fetus may induce marked cardiovascular impairments during pregnancy or in the neonatal period. In addition, recent studies have shown potential long-lasting postnatal effects that may increase cardiovascular risk in individuals gestated under chronic hypobaria. Hence, the maternal and fetal adaptive responses to hypoxia, influenced by HA ancestry, are vital for a better developmental and cardiovascular outcome of the offspring. This mini-review exposes and discusses the main determinants of vascular dysfunction due to developmental hypoxia at HA, such as the Andean Mountains, at the maternal and fetal/neonatal levels. Although significant advances have been made from Latin American studies, this area still needs further investigations to reveal the mechanisms involved in vascular dysfunction, to estimate complications of pregnancy and postnatal life adequately, and most importantly, to determine potential treatments to prevent or treat the pathological effects of being developed under chronic hypobaric hypoxia.