Clinical characteristics and sequelae of intrapartum hypertension : a retrospective cohort study

Background: In a significant proportion of pregnant women, elevated blood pressure may first present during the intrapartum period. This phenomenon, intrapartum hypertension, is often overlooked as blood pressure during delivery is attributed to labour pain, analgesic agents and haemodynamic changes. Thus the true prevalence and clinical significance of intrapartum hypertension remains unknown. This study sought to define the prevalence of intrapartum hypertension in previously normotensive women, identify associated clinical characteristics, and its impact on maternal and fetal outcomes. Methods: In this single-center retrospective cohort study, all available partograms were reviewed over a 1-month period at an outer metropolitan hospital in Sydney (Campbelltown Hospital). Women with diagnosed hypertensive disorders of pregnancy during the incident pregnancy were excluded. A total of 229 deliveries were included in the final analysis. Intrapatum hypertension (IH) was defined as two or more systolic blood pressure (SBP)⩾140 mmHg or diastolic blood pressure (DBP)⩾90 mmHg during the intrapartum. Demographic data at the time of the first antenatal visit for the incident pregnancy as well as final maternal outcomes (intrapartum and post-partum) and fetal outcomes were collected. Statistical analyses were carried out using SPSSv27 with adjustments for baseline variables. Results: Amongst 229 deliveries, 32 women (14%) had intrapartum hypertension. Older maternal age (p = 0.02), higher body mass index (p < 0.01) and higher diastolic blood pressure at the first antenatal visit (p = 0.03) were associated with intrapartum hypertension. A longer second stage of labour (p = 0.03), intrapartum non-steroidal anti-inflammatory medications (p < 0.01) and epidural anaesthesia (p = 0.03) were associated with intrapartum hypertension, while IV syntocin for labour induction was not. Women with intrapartum hypertension had a longer inpatient admission following delivery (p < 0.01), and elevated postpartum BP (p = 0.02) with discharge on antihypertensive medications (p < 0.01). Intrapartum hypertension was not associated with poor fetal outcomes, though subgroup analyses showed that women who had at least a single elevated blood pressure reading during the intrapartum experienced poorer fetal outcomes. Conclusion: In previously normotensive women, 14% developed intrapartum hypertension during delivery. This was associated with postpartum hypertension, longer maternal admission and discharge with antihypertensive medications. There was no difference in fetal outcomes

High-sensitivity troponin T and C-reactive protein have different prognostic values in hemo- and peritoneal dialysis populations : a cohort study

Background--Dialysis patients have an exceedingly high mortality rate. Biomarkers may be useful tools in risk stratification of this population. We evaluated the prognostic value of high-sensitivity cardiac troponin T (hs-cTnT) and CRP (C-reactive protein) in predicting adverse outcomes in stable hemodialysis and peritoneal dialysis (PD) patients. Variability in hs-cTnT was also examined. Methods and Results--A retrospective cohort study included 574 dialysis patients (hemodialysis 347, PD 227). Outcomes examined included mortality and major adverse cardiovascular events, with median follow-up of 3.5 years. hs-cTnT was an independent predictor of both outcomes in hemodialysis and PD patients. Increased risk only became significant when hs-cTnT reached quintile 3 ( > 49 ng/L). Area under the receiver operating curve analysis showed that the addition of hs-cTnT to clinical parameters significantly improved its prognostic performance for mortality in PD patients (P=0.002). CRP was an independent predictor of both outcomes in PD patients only. Only CRP in the highest quintile ( > 16.8 mg/L) was associated with increased risk. hs-cTnT remained relatively stable for the whole follow-up period for hemodialysis patients, whereas for PD patients, hs-cTnT increased by 23.63% in year 2 and 29.13% in year 3 compared with baseline (P < 0.001). Conclusions--hs-cTnT and CRP are useful tools in predicting mortality and major adverse cardiovascular events in hemodialysis and PD patients. Given that hs-cTnT levels increase over time in PD patients, interval monitoring may be valuable for risk assessment. In contrast, hs-cTnT in hemodialysis patients has little interval change and progress monitoring is not indicated

Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks

Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/ml) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/ml). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The antiangiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway

Menopausal hormone therapy is associated with having high blood pressure in postmenopausal women : observational cohort study

Background: The relationship between menopausal hormone therapy (MHT) and cardiovascular risk remains controversial, with a number of studies advocating the use of MHT in reducing risk of cardiovascular diseases, while others have shown it to increase risk. The aim of this study was to determine the association between menopausal hormone therapy and high blood pressure. Methods and Findings: A total of 43,405 postmenopausal women were included in the study. Baseline data for these women were sourced from the 45 and Up Study, Australia, a large scale study of healthy ageing. These women reported being postmenopausal, having an intact uterus, and had not been diagnosed with high blood pressure prior to menopause. Odds ratios for the association between MHT use and having high blood pressure were estimated using logistic regression, stratified by age (<56 years, 56-61 years, 62-70 years and over 71 years) and adjusted for demographic and lifestyle factors. MHT use was associated with higher odds of having high blood pressure: past menopausal hormone therapy use: <56 years (adjusted odds ratio 1.59, 99% confidence interval 1.15 to 2.20); 56-61 years (1.58, 1.31 to 1.90); 62-70 years (1.26, 1.10 to 1.44). Increased duration of hormone use was associated with higher odds of having high blood pressure, with the effect of hormone therapy use diminishing with increasing age. Conclusions: Menopausal hormone therapy use is associated with significantly higher odds of having high blood pressure, and the odds increase with increased duration of use. High blood pressure should be conveyed as a health risk for people considering MHT use

Magnetic resonance imaging detects placental hypoxia and acidosis in mouse models of perturbed pregnancies

Endothelial dysfunction as a result of dysregulation of anti-angiogenic molecules secreted by the placenta leads to the maternal hypertensive response characteristic of the pregnancy complication of preeclampsia. Structural abnormalities in the placenta have been proposed to result in altered placental perfusion, placental oxidative stress, cellular damage and inflammation and the release of anti-angiogenic compounds into the maternal circulation. The exact link between these factors is unclear. Here we show, using Magnetic Resonance Imaging as a tool to examine placental changes in mouse models of perturbed pregnancies, that T2 contrast between distinct regions of the placenta is abolished at complete loss of blood flow. Alterations in T2 (spin-spin or transverse) relaxation times are explained as a consequence of hypoxia and acidosis within the tissue. Similar changes are observed in perturbed pregnancies, indicating that acidosis as well as hypoxia may be a feature of pregnancy complications such as preeclampsia and may play a prominent role in the signalling pathways that lead to the increased secretion of anti-angiogenic compounds

Influence of gestational age at initiation of antihypertensive therapy: secondary analysis of CHIPS trial data (control of hypertension in pregnancy study)

For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes

Preeclamptic nephropathy

With the recent discovery of potential serum 'toxins' in human preeclampsia, it is timely to consider how these might relate to preeclamptic nephropathy. This review will discuss the clinical presentation of preeclampsia with an emphasis on renal involvement. It will explore the nature of the renal histological changes including endothelial and the more recently discovered podocyte changes, the implications of elevated anti-angiogenic molecules, anti-angiotensin-1 receptor agonistic antibodies and other proposed mechanisms in causing or exacerbating renal lesions. It will also explore the role of pre-existing renal disease in causing preeclampsia and the potential for new biomarkers, both serum and urinary, to inform clinical practice with regard to differentiating preeclampsia from pre-existing renal disease. Recommendations about the future of women who have had preeclampsia are unclear but the general consensus is that there are future cardiovascular risks, and to a lesser extent, future renal risks in these women. Regular review of proteinuria and glomerular filtration rate as well as overall cardiovascular risk status seems a logical step

Pregnancy-induced atypical haemolytic uremic syndrome : a new era with Eculizumab

Pregnancy is a well-recognised trigger of atypical haemolytic syndrome (P-aHUS) and often occurs in the post-partum period. Similar to atypical haemolytic uremic syndrome, it carries a poor prognosis with high morbidity particularly in the form of renal failure. Early recognition and intervention is crucial in its management particularly with the recent availability of Eculizumab, a humanized monoclonal antibody to complement component C5, which has demonstrated drastic improvement in prognosis. The issue, however, is arriving at a timely diagnosis given the considerable amount of overlap in the clinical and biochemical manifestation of P-aHUS, HELLP syndrome (haemolysis, elevated liver enzyme and low platelet count) and other hypertensive disorders of pregnancy. We present a case report and literature review that highlights the clinical conundrum of arriving at the diagnosis. We also highlight the importance of early management of P-aHUS with Eculizumab and its impact on improving morbidity

Placental growth factor and pre-eclampsia

Placental growth factor (PlGF) is an increasingly important molecule in the prediction, diagnosis and treatment of pre-eclampsia. It has pro-angiogenic effects on the feto-placental circulation and supports trophoblast growth. Mechanisms by which PlGF expression is regulated continue to be investigated. Low circulating PlGF precedes the manifestation of clinical disease in pre-eclamptic pregnancies and intrauterine growth restriction. This suggests that low PlGF is a marker of abnormal placentation, but it remains uncertain whether this is a cause or consequence. Prediction of pre-eclampsia using PlGF is promising and may assist in the targeting of resources to women at highest risk of adverse pregnancy outcomes. Promisingly, experimental animal models of pre-eclampsia have been successfully treated with supplemental PlGF. Treatment of pre-eclampsia with PlGF is a potential therapeutic option requiring further exploration. This review focuses specifically on the role of PlGF in normal and pathological placental development and in the clinical management of pre-eclampsia

Animal Models of Pre-eclampsia

The cardinal features of human pre-eclampsia, hypertension and proteinuria, are mimicked in animal models. Increasingly, the accuracy of inducing ‘pure’ systemic endothelial dysfunction is regarded as critical in differentiating mechanisms of pre-eclampsia from other conditions which induce hypertension (e.g. glomerulonephritis, renal denervation or manipulation of the renin-angiotensin system). A recent study in baboons has identified the timing of induction of maternal endothelial damage after acute uteroplacental ischaemia (UPI). The endothelial changes in the glomerulus are indicative of a direct endothelial toxin and mimic the lesions seen in human pre-eclampsia; the extent of hypertension and proteinuria are also similar. This animal model identifies systemic and placental sFLT-1 (soluble fms-like tyrosine kinase-1) as a potential mediator of endothelial damage. This research involving primates with haemomonochorial placentas makes translation of these results to humans very compelling for understanding the mechanisms of human disease. Similar endothelial dysfunction has been identified in baboons treated with anti-inflammatory inhibitors. Similar studies in rodents have identified a relationship between angiotensin II agonistic antibodies, UPI ⁄ reduced uteroplacental perfusion pressure, angiogenic markers, and cytokines. We can now identify vasoconstrictive mediators of the hypertensive and endothelial response such as endothelin 1, the renin-angiotensin system, or other hormones such as oestrogens in primate models