Maternal obesity and excess of fetal growth in pre-eclampsia

Placental syndromes and maternal cardiovascular health

The placental syndromes gestational hypertension, preeclampsia and intrauterine growth restriction are associated with an increased cardiovascular risk to the mother later in life. In this review, we argue that a woman's pre-conception cardiovascular health drives both the development of placental syndromes and long-term cardiovascular risk but acknowledge that placental syndromes can also contribute to future cardiovascular risk independent of pre-conception health. We describe how preclinical studies in models of preeclampsia inform our understanding of the links with later cardiovascular disease, and how current pre-pregnancy studies may explain relative contributions of both pre-conception factors and the occurrence of placental syndromes to long-term cardiovascular disease.

Evolutionary perspective of uteroplacental malperfusion: subjacent insult common to most pregnancy complications

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Ferroptosis and Its Emerging Role in Pre-Eclampsia

Iron is essential for cell survival, and iron deficiency is a known risk factor for many reproductive diseases. Paradoxically, such disorders are also more common in cases of iron overload. Here, we evaluated the role of ferroptosis in women’s health, particularly focusing on pre-eclampsia (PE). PE is a multisystem disorder and is one of the leading causes of maternal and perinatal morbidity and mortality, especially when the condition is of early onset. Nevertheless, the exact etiological mechanism of PE remains unclear. Interestingly, ferroptosis, as a regulated iron-dependent cell death pathway, involves a lethal accumulation of lipid peroxides and shares some characteristics with PE pathophysiology. In this review, we comprehensively reviewed and summarized recent studies investigating the molecular mechanisms involved in the regulation and execution of ferroptosis, as well as ferroptosis mechanisms in the pathology of PE. We propose that ferroptosis not only plays an important role in PE, but may also become a novel therapeutic target for PE.

The Relationship between Obesity and Pre-Eclampsia: Incidental Risks and Identification of Potential Biomarkers for Pre-Eclampsia

Obesity has been steadily increasing over the past decade in the US and worldwide. Since 1975, the prevalence of obesity has increased by 2% per decade, unabated despite new and more stringent guidelines set by WHO, CDC, and other public health organizations. Likewise, maternal obesity has also increased worldwide over the past several years. In the United States, pre-pregnancy rates have increased proportionally across all racial groups. Obesity during pregnancy has been directly linked to obstetric complications including gestational diabetes, HTN, hematomas, pre-eclampsia, and congenital defects. In the particular case of pre-eclampsia, the incidence rate across the globe is 2.16%, but the condition accounts for 30% of maternal deaths, and a robust body of evidence underscored the relationship between obesity and pre-eclampsia. More recently, attention has focused on the identification of reliable biomarkers predictive of an elevated risk for pre-eclampsia. The aim of this literature review is to elucidate the relationship between obesity and these predictive biomarkers for future prediction and prevention of pre-eclampsia condition in women at risk.

Gestational Diabetes Mellitus in Europe: A Systematic Review and Meta-Analysis of Prevalence Studies

Background

Gestational Diabetes Mellitus (GDM) is defined as the type of hyperglycemia diagnosed for the first-time during pregnancy, presenting with intermediate glucose levels between normal levels for pregnancy and glucose levels diagnostic of diabetes in the non-pregnant state. We aimed to systematically review and meta-analyze studies of prevalence of GDM in European countries at regional and sub-regional levels, according to age, trimester, body weight, and GDM diagnostic criteria.

Methods

Systematic search was conducted in five databases to retrieve studies from 2014 to 2019 reporting the prevalence of GDM in Europe. Two authors have independently screened titles and abstracts and full text according to eligibility using Covidence software. A random-effects model was used to quantify weighted GDM prevalence estimates. The National Heart, Lung, and Blood Institute criteria was used to assess the risk of bias.

Results

From the searched databases, 133 research reports were deemed eligible and included in the meta-analysis. The research reports yielded 254 GDM-prevalence studies that tested 15,572,847 pregnant women between 2014 and 2019. The 133 research reports were from 24 countries in Northern Europe (44.4%), Southern Europe (27.1%), Western Europe (24.1%), and Eastern Europe (4.5%). The overall weighted GDM prevalence in the 24 European countries was estimated at 10.9% (95% CI: 10.0-11.8, I2 : 100%). The weighted GDM prevalence was highest in the Eastern Europe (31.5%, 95% CI: 19.8-44.6, I2 : 98.9%), followed by in Southern Europe (12.3%, 95% CI: 10.9-13.9, I2 : 99.6%), Western Europe (10.7%, 95% CI: 9.5-12.0, I2 : 99.9%), and Northern Europe (8.9%, 95% CI: 7.9-10.0, I2 : 100). GDM prevalence was 2.14-fold increased in pregnant women with maternal age ≥30 years (versus 15-29 years old), 1.47-fold if the diagnosis was made in the third trimester (versus second trimester), and 6.79- fold in obese and 2.29-fold in overweight women (versus normal weight).

Conclusions

In Europe, GDM is significant in pregnant women, around 11%, with the highest prevalence in pregnant women of Eastern European countries (31.5%). Findings have implications to guide vigilant public health awareness campaigns about the risk factors associated with developing GDM.

Systematic Review Registration

PROSPERO [https://www.crd.york.ac.uk/PROSPERO/], identifier CRD42020161857.

A Review of Research Progress of Pregnancy with Twins with Preeclampsia

Preeclampsia has a significant long-term effect on the health of both mothers and babies. Preeclampsia-related pregnancy complications increase the morbidity and mortality of pregnant women and their fetuses by 5-8%. The recent advancement of assisted reproductive technology, combined with a rise in the number of elderly pregnant women, has resulted in pregnancy incidence with twins. Twins pregnant women have a 2-3 times greater risk of developing preeclampsia than singleton pregnant women, and it happens sooner and progresses faster. It is more severe and may appear in an atypical way. End-organ damage, such as renal failure, stroke, cardiac arrest, pulmonary edema, placental abruption, and cesarean section, are related maternal complications. Fetal growth retardation, stillbirth, and premature delivery with obstetric signs are all fetal complications. According to studies, all multiple pregnancies can take low-dose aspirin (60-150 mg) to minimize the risk of preeclampsia. To improve pregnancy outcomes and reduce the inherent risk of pregnancy with twins, twins should be handled as a high-risk pregnancy and treated differently than singletons. The literature on twin pregnancy with preeclampsia is the subject of this review. It will examine the current state of research on preeclampsia in pregnancy with twins, including the occurrence, diagnosis, and pathophysiological process. Moreover, the effect of pregnancy with twins on the perinatal outcome and pregnancy management of pregnancy with twins, including blood pressure management and preeclampsia prevention and treatment, is examined in this literature review. The goal is to figure out what kind of diagnosis and care you may need.

Preeclampsia and late fetal growth restriction

There is a strong but complex relationship between fetal growth restriction and preeclampsia. According to the International Society for the Study of Hypertension in Pregnancy the coexistence of gestational hypertension and fetal growth restriction identifies preeclampsia with no need for other signs of maternal organ impairment. While early-onset fetal growth restriction and preeclampsia are often strictly associated, such association becomes looser in the late preterm and term periods. The incidence of preeclampsia decreases dramatically from early preterm fetal growth restriction (39-43%) to late preterm fetal growth restriction (9-32%) and finally to term fetal growth restriction (4-7%). Different placental and cardiovascular mechanism underlie this trend: isolated fetal growth restriction has less frequent placental vascular lesions than fetal growth restriction associated with preeclampsia; moreover, late preterm and term fetal growth restriction show different patterns of maternal cardiac output and peripheral vascular resistance in comparison with preeclampsia. Consequently, current strategies for first trimester screening of placental dysfunction, originally implemented for preeclampsia, do not perform well for late-onset fetal growth restriction: the sensitivity of first trimester combined screening for small-for-gestational age newborns delivered at less than 32 weeks is 56-63%, and progressively decreases for those delivered at 32-36 weeks (43-48%) or at term (21-26%). Moreover, while the test is more sensitive for small-for-gestational age associated with preeclampsia at any gestational age, its sensitivity is much lower for small-for-gestational age without preeclampsia at 32-36 weeks (31-37%) or at term (19-23%).

Preeclampsia: The Relationship between Uterine Artery Blood Flow and Trophoblast Function

Maternal uterine artery blood flow is critical to maintaining the intrauterine environment, permitting normal placental function, and supporting fetal growth. It has long been believed that inadequate transformation of the maternal uterine vasculature is a consequence of primary defective trophoblast invasion and leads to the development of preeclampsia. That early pregnancy maternal uterine artery perfusion is strongly associated with placental cellular function and behaviour has always been interpreted in this context. Consistently observed changes in pre-conceptual maternal and uterine artery blood flow, abdominal pregnancy implantation, and late pregnancy have been challenging this concept, and suggest that abnormal placental perfusion may result in trophoblast impairment, rather than the other way round. This review focuses on evidence that maternal cardiovascular function plays a significant role in the pathophysiology of preeclampsia.

Sex differences in sympathetic activity in obesity and its related hypertension

The prevalence of obesity is rapidly increasing in the United States, particularly among women. Approximately 60-70% of hypertension in adults may be directly attributed to obesity. In addition, maternal obesity is a major risk factor for hypertensive disorders during pregnancy. The underlying mechanisms for the association between obesity and cardiovascular risk are multifactorial, but activation of the sympathetic nervous system is one significant contributing factor. This brief review summarizes the current knowledge on sex differences in sympathetic activity in obesity and its related hypertension, with a focus on studies in humans. Evidence suggests that abdominal visceral fat, rather than subcutaneous fat, is related to augmented sympathetic activity regardless of sex. Race/ethnicity may affect the relationship between obesity and sympathetic activity. Obesity-related hypertension has an important neurogenic component, which is characterized by sympathetic overactivity. However, sex may influence the association between hypertension and sympathetic overactivity in obese people. Finally, both body weight and sympathetic overactivity seem to be involved in the development of gestational hypertensive disorders in women. Chronic hyperinsulinemia due to insulin resistance, high plasma levels of leptin, and/or obstructive sleep apnea may be responsible for sympathetic overactivity in obesity-related hypertension.

Pre-eclampsia: pathogenesis, novel diagnostics and therapies

Pre-eclampsia is a complication of pregnancy that is associated with substantial maternal and fetal morbidity and mortality. The disease presents with new-onset hypertension and often proteinuria in the mother, which can progress to multi-organ dysfunction, including hepatic, renal and cerebral disease, if the fetus and placenta are not delivered. Maternal endothelial dysfunction due to circulating factors of fetal origin from the placenta is a hallmark of pre-eclampsia. Risk factors for the disease include maternal comorbidities, such as chronic kidney disease, hypertension and obesity; a family history of pre-eclampsia, nulliparity or multiple pregnancies; and previous pre-eclampsia or intrauterine fetal growth restriction. In the past decade, the discovery and characterization of novel antiangiogenic pathways have been particularly impactful both in increasing understanding of the disease pathophysiology and in directing predictive and therapeutic efforts. In this Review, we discuss the pathogenic role of antiangiogenic proteins released by the placenta in the development of pre-eclampsia and review novel therapeutic strategies directed at restoring the angiogenic imbalance observed during pre-eclampsia. We also highlight other notable advances in the field, including the identification of long-term maternal and fetal risks conferred by pre-eclampsia.

Integrated Systems Biology Approach Identifies Novel Maternal and Placental Pathways of Preeclampsia

Preeclampsia is a disease of the mother, fetus, and placenta, and the gaps in our understanding of the complex interactions among their respective disease pathways preclude successful treatment and prevention. The placenta has a key role in the pathogenesis of the terminal pathway characterized by exaggerated maternal systemic inflammation, generalized endothelial damage, hypertension, and proteinuria. This sine qua non of preeclampsia may be triggered by distinct underlying mechanisms that occur at early stages of pregnancy and induce different phenotypes. To gain insights into these molecular pathways, we employed a systems biology approach and integrated different "omics," clinical, placental, and functional data from patients with distinct phenotypes of preeclampsia. First trimester maternal blood proteomics uncovered an altered abundance of proteins of the renin-angiotensin and immune systems, complement, and coagulation cascades in patients with term or preterm preeclampsia. Moreover, first trimester maternal blood from preterm preeclamptic patients in vitro dysregulated trophoblastic gene expression. Placental transcriptomics of women with preterm preeclampsia identified distinct gene modules associated with maternal or fetal disease. Placental "virtual" liquid biopsy showed that the dysregulation of these disease gene modules originates during the first trimester. In vitro experiments on hub transcription factors of these gene modules demonstrated that DNA hypermethylation in the regulatory region of ZNF554 leads to gene down-regulation and impaired trophoblast invasion, while BCL6 and ARNT2 up-regulation sensitizes the trophoblast to ischemia, hallmarks of preterm preeclampsia. In summary, our data suggest that there are distinct maternal and placental disease pathways, and their interaction influences the clinical presentation of preeclampsia. The activation of maternal disease pathways can be detected in all phenotypes of preeclampsia earlier and upstream of placental dysfunction, not only downstream as described before, and distinct placental disease pathways are superimposed on these maternal pathways. This is a paradigm shift, which, in agreement with epidemiological studies, warrants for the central pathologic role of preexisting maternal diseases or perturbed maternal-fetal-placental immune interactions in preeclampsia. The description of these novel pathways in the "molecular phase" of preeclampsia and the identification of their hub molecules may enable timely molecular characterization of patients with distinct preeclampsia phenotypes.

The prediction of late-onset preeclampsia: Results from a longitudinal proteomics study

BACKGROUND

Late-onset preeclampsia is the most prevalent phenotype of this syndrome; nevertheless, only a few biomarkers for its early diagnosis have been reported. We sought to correct this deficiency using a high through-put proteomic platform.

METHODS

A case-control longitudinal study was conducted, including 90 patients with normal pregnancies and 76 patients with late-onset preeclampsia (diagnosed at ≥34 weeks of gestation). Maternal plasma samples were collected throughout gestation (normal pregnancy: 2-6 samples per patient, median of 2; late-onset preeclampsia: 2-6, median of 5). The abundance of 1,125 proteins was measured using an aptamers-based proteomics technique. Protein abundance in normal pregnancies was modeled using linear mixed-effects models to estimate mean abundance as a function of gestational age. Data was then expressed as multiples of-the-mean (MoM) values in normal pregnancies. Multi-marker prediction models were built using data from one of five gestational age intervals (8-16, 16.1-22, 22.1-28, 28.1-32, 32.1-36 weeks of gestation). The predictive performance of the best combination of proteins was compared to placental growth factor (PIGF) using bootstrap.

RESULTS

1) At 8-16 weeks of gestation, the best prediction model included only one protein, matrix metalloproteinase 7 (MMP-7), that had a sensitivity of 69% at a false positive rate (FPR) of 20% (AUC = 0.76); 2) at 16.1-22 weeks of gestation, MMP-7 was the single best predictor of late-onset preeclampsia with a sensitivity of 70% at a FPR of 20% (AUC = 0.82); 3) after 22 weeks of gestation, PlGF was the best predictor of late-onset preeclampsia, identifying 1/3 to 1/2 of the patients destined to develop this syndrome (FPR = 20%); 4) 36 proteins were associated with late-onset preeclampsia in at least one interval of gestation (after adjustment for covariates); 5) several biological processes, such as positive regulation of vascular endothelial growth factor receptor signaling pathway, were perturbed; and 6) from 22.1 weeks of gestation onward, the set of proteins most predictive of severe preeclampsia was different from the set most predictive of the mild form of this syndrome.

CONCLUSIONS

Elevated MMP-7 early in gestation (8-22 weeks) and low PlGF later in gestation (after 22 weeks) are the strongest predictors for the subsequent development of late-onset preeclampsia, suggesting that the optimal identification of patients at risk may involve a two-step diagnostic process.

Predicting preeclampsia from a history of preterm birth

Objective

To assess whether women with a history of preterm birth, independent on the presence of prelabour rupture of the membranes (PROM) and growth deviation of the newborn, are more likely to develop preeclampsia with preterm or preterm birth in a subsequent pregnancy.

Methods

We conducted a population-based cohort study, based on Medical Birth Registry of Norway between 1967 and 2012, including 742,980 women with singleton pregnancies who were followed up from their 1st to 2nd pregnancy. In the analyses we included 712,511 women after excluding 30,469 women with preeclampsia in the first pregnancy.

Results

After preterm birth without preeclampsia in the first pregnancy, the risk of preterm preeclampsia in the second pregnancy was 4–7 fold higher than after term birth (odds ratios 3.5; 95% confidence interval (CI) 3.0–4.0 to 6.5; 95% CI 5.1–8.2). The risk of term preeclampsia in the pregnancy following a preterm birth was 2–3 times higher than after term birth (odds ratios 1.6; 95% CI 1.5–1.8 to 2.6; 95% CI 2.0–3.4). After spontaneous non-PROM preterm birth and preterm PROM, the risk of preterm preeclampsia was 3.3–3.6 fold higher than after spontaneous term birth. Corresponding risks of term preeclampsia was 1.6–1.8 fold higher. No significant time trends were found in the effect of spontaneous preterm birth in the first pregnancy on preterm or term preeclampsia in the second pregnancy.

Conclusions

The results suggest that preterm birth, regardless of the presence of PROM, and preeclampsia share pathophysiologic mechanisms. These mechanisms may cause preterm birth in one pregnancy and preeclampsia in a subsequent pregnancy in the same woman. The association was particularly evident with preterm preeclampsia.

Biomarkers for Adverse Pregnancy Outcomes in Rheumatic Diseases

Pregnancy is a delicate balance of angiogenic factors. Adverse pregnancy outcomes in the form of placental insufficiency occur when antiangiogenic factors predominate, which manifests as maternal-placental syndrome (MPS). Women with rheumatic disease are at increased risk of MPS. Endothelial damage from circulating antiangiogenic factors and other inflammatory molecules in combination with preexisting maternal vascular risk factors is the likely underlying pathophysiological process for MPS. It is likely that these changes persist, and additional "insults" from ongoing inflammation, medications, and disease damage contribute to the development of accelerated cardiovascular disease seen in young women with rheumatic disease.

Race Disparities and Decreasing Birth Weight: Are All Babies Getting Smaller?

The mean infant birth weight in the United States increased for decades, but it might now be decreasing. Given race disparities in fetal growth, we explored race-specific trends in birth weight at Magee-Womens Hospital, Pittsburgh, Pennsylvania, from 1997 to 2011. Among singleton births delivered at 37-41 weeks (n = 70,607), we evaluated the proportions who were small for gestational age and large for gestational age and changes in mean birth weights over time. Results were stratified by maternal race/ethnicity. Since 1997, the number of infants born small for their gestational ages increased (8.7%-9.9%), whereas the number born large for their gestational ages decreased (8.9%-7.7%). After adjustment for gestational week at birth, maternal characteristics, and pregnancy conditions, birth weight decreased by 2.20 g per year (P < 0.0001). Decreases were greater for spontaneous births. Reductions were significantly greater in infants born to African-American women than in those born to white women (-3.78 vs. -1.88 per year; P for interaction = 0.010). Quantile regression models indicated that birth weight decreased across the entire distribution, but reductions among infants born to African-American women were limited to those in the upper quartile after accounting for maternal factors. Limiting the analysis to low-risk women eliminated birth weight reductions. Birth weight has decreased in recent years, and reductions were greater in infants born to African-American women. These trends might be explained by accumulation of risk factors such as hypertension and prepregnancy obesity that disproportionately affect African-American women. Our results raise the possibility of worsening race disparities in fetal growth.

Pre-eclampsia and preterm birth in Reunion Island: a 13 years cohort-based study. Comparison with international data

OBJECTIVES

To assess the prevalence of preterm birth in pre-eclamptic deliveries in Reunion Island, a tropical overseas French department (départements d'outre-mer, DOM) and to compare this prevalence with that of international literature.

METHODS

All singleton live-born deliveries referred to three maternity centers in Reunion Island over 13 years were eligible. Data for comparison were found through searches of MEDLINE, bibliographies of identified studies, proceedings of meetings on pre-eclampsia and contact with relevant researchers. Incidence of pre-eclampsia, proportion of preterm (<37(0/7) weeks gestation), late (34(0/7)-36(6/7) weeks) and early (<34(0/7) weeks) preterm birth in pre-eclamptic deliveries were analyzed.

RESULTS

Pre-eclampsia occurred in 2.3% of 51 927 singleton live-born deliveries in Reunion Island. The prevalence of preterm birth among pre-eclamptic deliveries was 59.8% (28.6% late and 31.2% early preterm birth). Among identified reports, only one prospective study from Canada (1986-1995) described preterm and early preterm birth rates higher than Reunion Island. A cohort-based report from Guadeloupe, another tropical French DOM, showed a preterm birth prevalence of 60.9%, with 30.8% of early preterm birth.

CONCLUSIONS

Predominance of early- or late-onset pre-eclampsia has huge geographical differences. Further investigations are required to address risk factors for preterm birth and early onset pre-eclampsia in French DOM.

Pre-eclampsia and assisted reproductive technologies: consequences of advanced maternal age, interbirth intervals, new partner and smoking habits

OBJECTIVE

To examine the risk of pre-eclampsia (PE) in women conceiving after assisted reproductive technologies (ART). Potential confounding from maternal age, long intervals between births, new partner and smoking were evaluated.

DESIGN AND SETTING

Population-based cohort study with data from the Medical Birth Registry of Norway.

POPULATION

A total of 501,766 mothers with offspring from 1988 to 2009.

METHODS

Births to the same mother were linked in sibship data files with information of ART.

MAIN OUTCOME MEASURES

Odds ratio (OR) (95% confidence intervals) of PE in pregnancies conceived by ART compared with spontaneous conception, stratified by parity.

RESULTS

The prevalence of PE was 5.1% in first, 2.2% in second and 2.1% in third pregnancies. Corresponding figures in ART pregnancies were 6.0%, 3.3% and 4.4%. Hence, the odds ratios of PE in ART pregnancies relative to spontaneous pregnancies increased from 1.2 (1.1-1.3) in first, 1.5 (1.3-1.8) in second to 2.1 (1.4-3.3) in third pregnancies. Adjusting by maternal age lowered the odds ratio to 1.3 (1.1-1.6) and 1.8 (1.2-2.8) in second and third pregnancies, respectively. Multi-adjusted, birth interval had more impact than change of partner. Smoking was associated with a strongly reduced PE risk (odds ratio 0.65; 0.62-0.69), but there was no confounding by smoking on the ART associated risk.

CONCLUSIONS

Assisted reproductive technologies increases the risk of PE, and the risk may increase by parity. The association between ART pregnancies and PE is to some extent explained by interbirth intervals and advanced maternal age, but not to change of partner or smoking.