An observational claims data analysis on the risk of maternal chronic kidney disease after preterm delivery and preeclampsia

Heme oxygenase/carbon monoxide system affects the placenta and preeclampsia

Preeclampsia affects 2% to 8% of pregnancies worldwide and results in significantly high maternal and perinatal morbidity and mortality, with delivery being the only definitive treatment. It is not a single disorder, but rather a manifestation of an insult(s) to the uteroplacental unit -whether maternal, fetal, and/or placental. Multiple etiologies have been implicated, including uteroplacental ischemia, maternal infection and/or inflammation, maternal obesity, sleep disorders, hydatidiform mole, maternal intestinal dysbiosis, autoimmune disorders, fetal diseases, breakdown of maternal-fetal immune tolerance, placental aging, and endocrine disorders. Early- and late-onset preeclampsia are associated with different etiologies: early-onset preeclampsia develops because of poor placentation, while late-onset preeclampsia occurs in women with latent maternal endothelial dysfunction. In preeclamptic placentas, acquired, genetic, and immune risk factors may result in impaired trophoblast invasion and spiral artery remodeling, which affects uteroplacental perfusion. The resulting placental hypoxia affects the heme oxygenase system-a known stress response pathway affected by hypoxia that is important during normal pregnancy and may offer a therapeutic approach in preeclampsia. This review will address the effect of the heme oxygenase/carbon monoxide system on the placenta and preeclampsia.

Association between preterm delivery and the risk of maternal renal disease: A systematic review and meta‑analysis

The present systematic review and meta-analysis aimed to generate high-quality evidence on the association between preterm delivery (PTD) and subsequent risk of renal disease in the mother. A literature search was conducted on PubMed, Embase, CENTRAL and Scopus until the 15th of May 2023 for studies reporting an adjusted association between PTD and the risk of maternal renal disease. A total of seven studies were eligible. The pooled analysis found that women with PTD had a statistically significant increased risk of chronic kidney disease in the long term [hazard ratio (HR): 1.82 95% confidence interval (CI): 1.38, 2.40; I2=85%]. Similarly, the meta-analysis also found a statistically significant increased risk of end-stage renal disease (ESRD) amongst women with PTD as compared with those without PTD (HR: 2.22 95% CI: 1.95, 2.53; I2=0%). Overall, the pooled analysis showed a significantly higher incidence of renal disorders with PTD (HR: 1.98; 95% CI: 1.57, 2.50; I2=88%). The results were unchanged on sensitivity analysis. Women with PTD could be at increased risk of future chronic kidney disease and ESRD. The small number of studies and retrospective nature of data are important limitations. Further studies are needed to supplement the available evidence.

Assessing Severity and Need for Delivery in Early Onset Preeclampsia Before 32 Weeks of Gestation: a Delphi Consensus Procedure

Background

Preeclampsia is a potentially life-threatening hypertensive pregnancy disorder that carries an acute risk of an unfavorable outcome of the pregnancy but also has consequences for the long-term health of the mother. Women who develop the early form of pre-eclampsia before the 32nd week of pregnancy have the highest risk and are also the most difficult to treat. The severity of pre-eclampsia is not characterized uniformly in Germany, so that the indication for delivery is rather individualized. The aim of this study was to reach a consensus on parameters that could serve as criteria for describing the severity of pre-eclampsia based on the urgency of delivery. To this end, a Delphi procedure was used to present a scenario in which a woman was admitted for preeclampsia before 32 gestational weeks and after completion of antenatal steroid therapy.

Methods

Clinicians specialized in maternal-fetal medicine from German-speaking countries completed five rounds of a modified Delphi questionnaire. Presented parameters were selected by the section "Hypertensive Pregnancy Diseases and Fetal Growth Restriction" of the German Society of Gynecology and Obstetrics after reviewing the literature. These included objectifiable laboratory or clinical parameters as well as subjective symptoms of the patient. In addition, nine fetal parameters were taken into account. The clinicians were asked to rate presented parameters as an indication for delivery on a Likert scale from 0 to 4 (no indication to absolute indication without delay). For each item, the predefined cut-off for group consensus was ≥ 70% agreement.

Results

A total of 126 experts were approached. Sixty-nine experts (54.8%) took part in the first round; of those 50 completed the entire Delphi procedure. A consensus was reached on 14 parameters to be considered rapid preparation for delivery without delay (4 points on the Likert scale). These were among others hepatic hematoma or liver capsule rupture, acute liver failure with fulminant coagulation disorder or disseminated intravascular coagulation, eclampsia, pathologic findings in imaging (e.g. cMRI) or electrocardiogram arranged for new onset of headache or retrosternal pain, respectively. Twenty-six parameters were rated as factors that should be considered in the decision without being absolute (1 to 3 points), and 13 parameters should have no influence on the decision to deliver (0 points). No consensus on severe hypertension as an indication for delivery could be reached for blood pressure values below 220/140 mmHg.

Conclusion

A consensus was reached on whether to deliver in preeclampsia typic clinical findings and symptoms. The results can serve as guidance for current clinical practice and for the definition of clinical endpoints in intervention studies. Nevertheless, the isolated criteria are a theoretical construction since the combined deterioration or summation of several factors rather than a single factor most likely influences the decision to deliver and reflect the severity of preeclampsia. Moreover, the degree of hypertension as an indication for delivery remains controversial, unless the patient suffers additionally from complaints. Future research should be enforced to incorporate long-term risks for the mother into a decision aid.

Placental and Renal Pathways Underlying Pre-Eclampsia

Pre-eclampsia is a serious complication of pregnancy characterized by a state of multiorgan hypertensive disorders, with or without proteinuria and possible multiorgan dysfunction. Chronic kidney disease is an established risk factor for the development of pre-eclampsia, as angiogenic homeostasis is altered and the maternal circulation is already hypertensive. Facing pre-eclampsia in the context of chronic kidney disease is a challenging emergency for both the mother and the fetus. The clinical features and the management of this multi-organ disorder are clearly defined in the modern literature but the underlying pathophysiologic mechanisms remain not fully elucidated. Understanding the pathophysiology that mediates the onset of pre-eclampsia itself and in synergy with chronic kidney disease is fundamental for developing prompt prevention strategies, treatment planning, and patient counseling. This review aims to summarize the main molecular mechanisms involved in the process of pre-eclampsia, with a particular focus on the role of the kidneys and hormonal pathways related to renal function in normal pregnancy and pre-eclamptic syndromes.

Urine excretion of C3dg and sC5b-9 coincide with proteinuria and development of preeclampsia in pregnant women with type-1 diabetes

OBJECTIVE

Pregnant women with type-1 diabetes have an increased risk of preeclampsia with kidney injury and cardiovascular complications. Urine excretion of plasmin and soluble membrane attack complex (sC5b-9) is elevated in severe preeclampsia. We hypothesized a coupling between these events and that active plasmin promotes intratubular complement activation and membrane deposition.

METHODS

Stored urine and plasma samples from pregnant women with type-1 diabetes (n = 88) collected at gestational weeks 12, 20, 28, 32, 36 and 38 were used. In the cohort, 14 women developed preeclampsia and were compared with 16 nonpreeclampsia controls.

RESULTS

Urine C3dg and sC5b-9-associated C9 neoantigen/creatinine ratios increased and were significantly higher in women who developed preeclampsia. Plasma concentrations did not change with gestation. Urine plasmin(ogen) correlated to urine C3dg (r = 0.51, P < 0.001) and C9 neoantigen (r = 0.68, P < 0.001); urine albumin correlated to C3dg (r = 0.44, P < 0.001) and C9 (r = 0.59, P < 0.001). Membrane-associated C3dg and C9 neoantigen was detected in urinary extracellular vesicles from patients but not controls at 36 weeks. Receiver operating characteristic curves showed that C3dg and C9 neoantigen were inferior to albumin as predictive biomarkers for preeclampsia.

CONCLUSION

In preeclampsia, urinary excretion of activated complement relates significantly to albuminuria and to plasmin(ogen) but not to activation in plasma. Intratubular complement activation in preeclampsia is a postfiltration event tightly related to proteinuria/plasminogenuria and a possible mechanistic link to cellular damage and kidney injury.

Observational database study on preeclampsia and postpartum medical care up to 7.5 years after birth

Preeclampsia is associated with a substantially increased long-term risk for cardiovascular, cerebrovascular and renal disease. It remains unclear whether and to which extent specialized medical postpartum care is sought. We aimed to assess current utilization of postpartum primary and specialized care and medication prescription behavior in women who experienced preeclampsia. This retrospective observational study based on statutory claims data included 193,205 women with 258,344 singleton live births between 2010 and 2017 in Southern Germany. Postpartum care was evaluated by analyzing and comparing the frequency of medical consultations in primary and specialized care and prescriptions for antihypertensive medication among women with and without preeclampsia up to 7.5 years after delivery. Gynecologists and general practitioners were the main health care providers for all women. Although specialized postpartum care was sought by more women after preeclampsia, the effect size indices revealed no considerable association between a history of preeclampsia and the utilization of specialized outpatient aftercare (e.g. 2% vs. 0.6% of patients with and without preeclampsia who consulted a nephrologist during the first year postpartum, r = 0.042). Preeclampsia was associated with an increased risk to take any antihypertensive medication after delivery (HR 2.7 [2.6; 2.8]). Postpartum referral to specialized outpatient care and quarterly prescriptions of antihypertensives following preeclampsia failed to match the early and rapidly increased incidence and risk of hypertension. These data highlight the missed opportunity to implement a reasonable follow-up strategy and prevention management in order to achieve long-term clinical benefits.