An expert discussion on the atypical hemolytic uremic syndrome nomenclature-identifying a road map to precision: a report of a National Kidney Foundation Working Group.

The term atypical hemolytic uremic syndrome has been in use since the mid-1970s. It was initially used to describe the familial or sporadic form of hemolytic uremic syndrome as opposed to the epidemic, typical form of the disease. Over time, the atypical hemolytic uremic syndrome term has evolved into being used to refer to anything that is not Shiga toxin-associated hemolytic uremic syndrome. The term describes a heterogeneous group of diseases of disparate causes, a circumstance that makes defining disease-specific natural history and/or targeted treatment approaches challenging. A working group of specialty-specific experts in the thrombotic microangiopathies was convened to review the validity of this broad term in an era of swiftly advancing science and targeted therapeutics. A Delphi approach was used to define and interrogate some of the key issues related to the atypical hemolytic uremic syndrome nomenclature.

Identification of complement factor H variants that predispose to pre-eclampsia: A genetic and functional study.

OBJECTIVE: The objective of the study was to investigate the role of genetic variants in complement proteins in pre-eclampsia. DESIGN: In a case-control study involving 609 cases and 2092 controls, five rare variants in complement factor H (CFH) were identified in women with severe and complicated pre-eclampsia. No variants were identified in controls. SETTING: Pre-eclampsia is a leading cause of maternal and fetal morbidity and mortality. Immune maladaptation, in particular, complement activation that disrupts maternal-fetal tolerance leading to placental dysfunction and endothelial injury, has been proposed as a pathogenetic mechanism, but this remains unproven. POPULATION: We genotyped 609 pre-eclampsia cases and 2092 controls from FINNPEC and the national FINRISK cohorts. METHODS: Complement-based functional and structural assays were conducted in vitro to define the significance of these five missense variants and each compared with wild type. MAIN OUTCOME MEASURES: Secretion, expression and ability to regulate complement activation were assessed for factor H proteins harbouring the mutations. RESULTS: We identified five heterozygous rare variants in complement factor H (L3V, R127H, R166Q, C1077S and N1176K) in seven women with severe pre-eclampsia. These variants were not identified in controls. Variants C1077S and N1176K were novel. Antigenic, functional and structural analyses established that four (R127H, R166Q, C1077S and N1176K) were deleterious. Variants R127H and C1077S were synthesised, but not secreted. Variants R166Q and N1176K were secreted normally but showed reduced binding to C3b and consequently defective complement regulatory activity. No defect was identified for L3V. CONCLUSIONS: These results suggest that complement dysregulation due to mutations in complement factor H is among the pathophysiological mechanisms underlying severe pre-eclampsia.

Maternal and fetal outcomes of pregnancy occurring after a diagnosis of immune-mediated thrombotic thrombocytopenic purpura.

Pregnancy is a well-established trigger for a first episode or relapse of immune thrombotic thrombocytopenic purpura (iTTP). Other outcomes of subsequent pregnancy after a diagnosis of iTTP are less well described. We conducted this retrospective cohort study to evaluate maternal and fetal outcomes of pregnancy in women with prior iTTP from the Johns Hopkins Thrombotic Microangiopathy Cohort. Of 168 women in the cohort, 102 were of reproductive age at diagnosis. Fourteen pregnancies (in 9 women) that occurred after the initial iTTP episode were included in the analysis. iTTP relapse occurred in 9 (64%) pregnancies. Out of the 9 instances of relapse, 5 relapses occurred in 2 women. Seven pregnancies (50%) ended in fetal death or miscarriage in the setting of iTTP relapse and three were electively terminated due to fear of relapse. Four pregnancies (50% of the 8 that progressed beyond 20 weeks) were complicated by preeclampsia or HELLP syndrome, which is over ten-fold higher than that of the general population. No maternal deaths occurred. Only 4 pregnancies resulted in live births, of which, 2 were pre-term. Pregnancy in women with prior iTTP is associated with a substantial risk of iTTP relapse and fetal loss. Preeclampsia and HELLP syndrome is also more common than that in the general population. ADAMTS13 monitoring and preemptive therapy may improve pregnancy outcomes, which needs to be evaluated prospectively.

Complement activation and regulation in preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome.

The complement system is critical to human health owing to its central role in host defense and innate immunity. During pregnancy, the complement system must be appropriately regulated to allow for immunologic tolerance to the developing fetus and placenta. Although some degree of complement activation can be seen in normal pregnancy, the fetus seems to be protected in part through the placental expression of complement regulatory proteins, which inhibit complement activation at different steps along the complement activation cascade. In women who develop preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, there is a shift toward increased complement activation and decreased complement regulation. There is an increase in placental deposition of C5b-9, which is the terminal effector of classical, lectin, and alternative complement pathways. C5b-9 deposition stimulates trophoblasts to secrete soluble fms-like tyrosine kinase-1, which sequesters vascular endothelial growth factor and placental growth factor. Pathogenic mutations or deletions in complement regulatory genes, which predispose to increased complement activation, have been detected in women with preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome. Before the disease, biomarkers of alternative complement pathway activation are increased; during active disease, biomarkers of terminal complement pathway activation are increased. Urinary excretion of C5b-9 is associated with preeclampsia with severe features and distinguishes it from other hypertensive disorders of pregnancy. Taken together, existing data link preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome with increased activation of the terminal complement pathway that, in some cases, may be influenced by genetic alterations in complement regulators. These findings suggest that the inhibition of the terminal complement pathway, possibly through C5 blockade, may be an effective strategy to treat preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, but this strategy warrants further evaluation in clinical trials.

Association Between Low-Dose Aspirin and Development of Gestational Diabetes: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate the association between the use of low-dose aspirin for preeclampsia prophylaxis and risks of gestational diabetes (primary outcome), neonatal hypoglycemia, macrosomia, large for gestational age, birth trauma, and shoulder dystocia (secondary outcomes). DATA SOURCES: We searched Ovid MEDLINE, Embase, CINAHL, and Cochrane/CENTRAL for studies published between January 1, 1989, and April 24, 2021. STUDY SELECTION: Randomized controlled trials (RCTs) or cohort studies of any size conducted in any setting were included. DATA EXTRACTION AND SYNTHESIS: We assessed risk of bias using the Cochrane Risk of Bias tool 2.0 (for RCTs) and the Newcastle-Ottawa Scale (for cohort studies). We meta-analyzed relative risks (RRs) using random-effects models. CONCLUSIONS: Our search retrieved 4441 records, of which 9 studies (6 RCTs with 1932 patients and 3 cohort studies with 313 837 patients) met inclusion criteria. We rated only 4 of the 6 RCTs and 1 of the 3 cohort studies at low risk of bias. Low-dose aspirin in pregnancy for preeclampsia prophylaxis was not associated with a greater risk of gestational diabetes (RR 1.18; 95% confidence interval 0.80-1.74). No studies reported data for the secondary outcomes. In summary, the use of low-dose aspirin does not appear associated with risk of gestational diabetes. The poor quality and small number of studies limit the interpretation of these results.

Evaluation of Low-Dose Aspirin to Prevent Preeclampsia in Pregnant People with Chronic Hypertension.

OBJECTIVE: Our objective was to evaluate if the use of low-dose aspirin (LDA) among pregnant individuals with chronic hypertension (CHTN) reduces the rate of superimposed preeclampsia or other adverse maternal and neonatal outcomes. STUDY DESIGN: Our study included single-center cohort of pregnant individuals with CHTN who had a live birth after 23 weeks' gestation, between 2013 and 2018. The primary exposure was the use of LDA in pregnancy and the primary outcome was superimposed preeclampsia. LDA use was also evaluated by the timing of initiation, before or after 16 weeks' gestation. Secondary outcomes included preeclampsia subtypes (e.g., preeclampsia with severe features, early-onset disease), as well as adverse maternal and neonatal outcomes. Differences were analyzed by χ 2, Fisher's exact, or t tests, with logistic regression to adjust for confounders. RESULTS: Of 11,825 deliveries during the study period, 494 (4.2%) occurred in women with CHTN. Among those with CHTN, 174 (35%) were prescribed LDA, most often 81 mg daily (173 out of 174, 99%). Baseline characteristics were similar between groups, but the history of preeclampsia was more common in those prescribed LDA. The rate of superimposed preeclampsia was no different among those with CHTN-prescribed LDA compared with those who were not (36% vs. 30%, p = 0.2), even when restricting the analysis to those prescribed LDA before 16 weeks' gestation (33 vs. 30%, p = 0.2). In addition, LDA did not lead to a reduction in the rate of preeclampsia with severe features, early-onset preeclampsia, or other adverse maternal outcomes. However, the composite rate of adverse neonatal outcomes was lower in LDA users versus nonusers (4.0 vs. 13%, p = 0.002), which persisted after multivariable adjustment (adjusted odds ratio: 0.28, 95% confidence interval: 0.12-0.67). CONCLUSION: Among pregnant individuals with CHTN, LDA did not decrease the rate of superimposed preeclampsia. Further studies are warranted to validate our observed reduction in adverse neonatal outcomes and to determine if aspirin is more beneficial at dosages greater than 81 mg daily. KEY POINTS: · Superimposed preeclampsia rates are the same regardless of LDA.. · Decreased rate of adverse neonatal outcomes is seen with LDA.. · No decrease in adverse maternal outcomes is seen with LDA..

Compassionate Use of Remdesivir in Pregnant Women With Severe Coronavirus Disease 2019.

BACKGROUND: Remdesivir is efficacious for severe coronavirus disease 2019 (COVID-19) in adults, but data in pregnant women are limited. We describe outcomes in the first 86 pregnant women with severe COVID-19 who were treated with remdesivir. METHODS: The reported data span 21 March to 16 June 2020 for hospitalized pregnant women with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection and room air oxygen saturation ≤94% whose clinicians requested remdesivir through the compassionate use program. The intended remdesivir treatment course was 10 days (200 mg on day 1, followed by 100 mg for days 2-10, given intravenously). RESULTS: Nineteen of 86 women delivered before their first dose and were reclassified as immediate "postpartum" (median postpartum day 1 [range, 0-3]). At baseline, 40% of pregnant women (median gestational age, 28 weeks) required invasive ventilation, in contrast to 95% of postpartum women (median gestational age at delivery 30 weeks). By day 28 of follow-up, the level of oxygen requirement decreased in 96% and 89% of pregnant and postpartum women, respectively. Among pregnant women, 93% of those on mechanical ventilation were extubated, 93% recovered, and 90% were discharged. Among postpartum women, 89% were extubated, 89% recovered, and 84% were discharged. Remdesivir was well tolerated, with a low incidence of serious adverse events (AEs) (16%). Most AEs were related to pregnancy and underlying disease; most laboratory abnormalities were grade 1 or 2. There was 1 maternal death attributed to underlying disease and no neonatal deaths. CONCLUSIONS: Among 86 pregnant and postpartum women with severe COVID-19 who received compassionate-use remdesivir, recovery rates were high, with a low rate of serious AEs.

Situs inversus totalis and prenatal diagnosis of a primary ciliary dyskinesia.

Situs inversus, a condition in which the major visceral organs are reversed from their normal positions in the body, can be detected by prenatal ultrasonography. Often benign, it may be associated with primary ciliary dyskinesia, an autosomal recessive disorder characterized by chronic respiratory disease. Yet, prenatal diagnosis of primary ciliary dyskinesia has not been reported. We describe a pregnancy in which situs inversus was diagnosed by fetal ultrasound at 20 weeks gestation. Prenatal testing for primary ciliary dyskinesia led to the discovery that both parents were asymptomatic carriers of a pathogenic mutation in the CCDC103 gene, with an affected neonate.

Delivery and neuraxial technique outcomes in patients with hemophilia and in hemophilia carriers: a systematic review.

Female carriers are more common than males with hemophilia and unrecognized factor VIII or IX deficiency is associated with intrauterine growth retardation, epidural hematomas, blood transfusion, and peripartum hemorrhage. A review was conducted to assess the evidence for professional society recommendations for > 50% factor levels during labor. Two searches of Pubmed, CINAHL, Cochrane, and Google Scholar were completed in October 2019. The first for case reports and series described neuraxial techniques in patients with hemophilia-regardless of sex, age, or pregnant status. The second for case reports and series described bleeding outcomes of parturients with hemophilia. Primary outcomes were diagnosis of neuraxial hematoma (first search) and postpartum bleeding complications (second search). Thirteen articles (n = 134) described neuraxial techniques in patients with hemophilia. Neuraxial hematoma with paraplegia occurred in 3/134 patients-all had a factor level of 1%. Nineteen articles (2712 deliveries in 2657 women) described bleeding outcomes. Postpartum hemorrhage occurred in 7.1% (193/2712) of deliveries, of which 60% necessitated blood transfusion. Postpartum bleeding complications were twice as likely (51.0% [25/49] vs. 25.6% [52/203], P < 0.001) with factor activity < 50%. Therefore, factor levels should be assessed and increased above 50% prior to neuraxial technique and delivery.Trial registration: PROSPERO 2018 CRD42018110215.

Atypical hemolytic uremic syndrome and complement blockade: established and emerging uses of complement inhibition.

PURPOSE OF REVIEW: Atypical hemolytic uremic syndrome (aHUS) is a diagnosis that has captured the interest of specialists across multiple fields. The hallmark features of aHUS are microangiopathic hemolysis and thrombocytopenia, which creates a diagnostic dilemma because of the occurrence of these findings in a wide variety of clinical disorders. RECENT FINDINGS: In most of the instances, aHUS is a diagnosis of exclusion after ruling out causes such as Shigella toxin, acquired or genetic a disintegrin and metalloproteinase thrombospondin motif 13 deficiency (thrombotic thrombocytopenic purpura), and vitamin B12 deficiency. In the purest sense, aHUS is a genetic condition that is activated (or unmasked) by an environmental exposure. However, it is now evident that complement activation is a feature of many diseases. Variants in complement regulatory genes predispose to microangiopathic hemolysis in many rheumatologic, oncologic, and drug-induced vascular, obstetric, peritransplant, and infectious syndromes. SUMMARY: Many 'hemolysis syndromes' overlap clinically with aHUS, and we review the literature on the treatment of these conditions with complement inhibition. New reports on the treatment of C3 glomerulopathy, Shiga toxin-related classic hemolytic uremic syndrome, and medication-related thrombotic microangiopathy will be reviewed as well.

Assessment of blood-brain barrier integrity and neuroinflammation in preeclampsia.

BACKGROUND: Although blood-brain barrier integrity is intact under normal pregnancy conditions, animal studies suggest that blood-brain barrier impairment occurs in preeclampsia. Yet, human data are limited, and the integrity of the blood-brain barrier has not been assessed in women with preeclampsia. OBJECTIVE: We sought to test the hypothesis that the integrity of the blood-brain barrier is impaired and that neuroinflammation is increased in women with preeclampsia. STUDY DESIGN: We performed an observational case-control study in pregnant women >24 weeks gestation who underwent spinal anesthesia for elective cesarean delivery or combined spinal epidural analgesia for labor. Cases were women with preeclampsia, and control subjects were women with either healthy pregnancy, chronic hypertension, or gestational hypertension. Paired samples of blood, urine, and cerebrospinal fluid were collected from each subject before delivery. We measured albumin, C5a, C5b-9, tumor necrosis factor-α, and interleukin-6 concentrations in plasma and cerebrospinal fluid, and albumin, C5a, and C5b-9 concentrations in urine, using colorimetric or enzyme-linked immunosorbent assays. The ratio of albumin in cerebrospinal fluid to plasma (Qalb) was used as a surrogate for maternal blood-brain barrier integrity. Cerebrospinal fluid concentrations of C5a, C5b-9, tumor necrosis factor-α, and interleukin-6 were used as surrogate markers of neuroinflammation. Differences in Qalb and cerebrospinal fluid protein concentrations between groups were assessed by nonparametric test of medians. RESULTS: Forty-eight subjects were enrolled, which included 16 cases with preeclampsia, 16 control subjects with healthy pregnancy, and 16 control subjects with either chronic or gestational hypertension. Qalb values were not increased in preeclampsia cases compared with healthy or hypertensive control subjects (Qalb median, 3.5 [interquartile range, 2.9-5.1] vs 3.9 [interquartile range, 3.0-4.8] vs 3.9 [interquartile range, 3.0-4.8]; P=.78]. Moreover, Qalb values were not increased in the subset of women with preeclampsia with severe features (n=8) compared with those without severe features (n=8; Qalb median, 3.5 [interquartile range, 3.3-4.9] vs 3.7 [interquartile range, 2.3-5.5]; P=.62]. Cerebrospinal fluid concentrations of C5a, C5b-9, tumor necrosis factor-α and interleukin-6 were not increased in cases of preeclampsia, compared with control subjects with either healthy pregnancy, chronic hypertension, or gestational hypertension (P>.05, all comparisons). In contrast to the negative findings in cerebrospinal fluid, plasma concentrations of both C5b-9 and interleukin-6 and urine concentrations of C5a and C5b-9 were increased in cases of preeclampsia. CONCLUSION: Through measurements of albumin, complement proteins, and cytokines in paired samples of blood and cerebrospinal fluid at the time of delivery, we found no evidence of blood-brain barrier impairment or neuroinflammation in preeclampsia. Larger studies that will investigate a wider range of proteins are suggested to validate our findings.

Successful use of eculizumab to treat atypical hemolytic uremic syndrome in patients with inflammatory bowel disease.

BACKGROUND: Atypical hemolytic uremic syndrome is a rare group of disorders that have in common underlying complement amplifying conditions. These conditions can accelerate complement activation that results in a positive feedback cycle. The known triggers for complement activation can be diverse and include, infection, autoimmune disease, and malignancy. Recent reports suggest that certain autoimmune and rheumatological triggers of complement activation may result in atypical hemolytic uremic syndrome that does not resolve despite treating the underlying disorder. Specifically, patients with systemic lupus erythematosus and microangiopathic hemolysis may not respond to treatment of their underlying rheumatological trigger but responded to complement blockade. CASE PRESENTATIONS: We report two patients with inflammatory bowel disease complicated by development of atypical hemolytic uremic syndrome. In both cases, patients were on treatment for inflammatory bowel disease, that was not well controlled/flaring at the time. The first patient is a male who developed Crohn's disease and microangiopathic hemolysis at age 5 and was treated with eculizumab successfully. Discontinuation of the medication led to multiple relapses, and the patient currently is being treated with eculizumab and has normal hematological and stable renal parameters. The second patient is a 49-year-old female with Ulcerative Colitis treated with 6-Mercaptopurine. She developed acute kidney injury and microangiopathic hemolysis. Prompt diagnosis and treatment with eculizumab resulted in the recovery of kidney injury along with a complete hematological response. CONCLUSIONS: These two cases are the fifth and sixth patients to be published in the literature with atypical hemolytic uremic syndrome and inflammatory bowel disease treated with complement blockade. This confirms that C5 complement blockade is effective in treating complement mediated thrombotic microangiopathy/atypical hemolytic uremic syndrome when it is triggered in patients with inflammatory bowel disease.

Treatment of Iron Deficiency Anemia in Pregnancy with Intravenous versus Oral Iron: Systematic Review and Meta-Analysis.

OBJECTIVE: To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the benefits of intravenous (IV) iron in pregnancy. STUDY DESIGN: Systematic review was registered with PROSPERO and performed using PRISMA guidelines. PubMed, MEDLINE, Web of Science, ClinicalTrials.gov, Cochrane Library, and Google Scholar were searched. Eleven RCTs, comparing IV to oral iron for treatment of iron-deficiency anemia in pregnancy, were included. Meta-analyses were performed with Stata software (College Station, TX), utilizing random effects model and method of DerSimonian and Laird. Outcomes were assessed by pooled odds ratios (OR) or pooled weighted mean difference (WMD). Sensitivity analyses were performed for heterogeneity. RESULTS: We found that pregnant women receiving IV iron, compared with oral iron, had the following benefits: (1) Achieved target hemoglobin more often, pooled OR 2.66 (95% confidence interval [CI]: 1.71-4.15), p < 0.001; (2) Increased hemoglobin level after 4 weeks, pooled WMD 0.84 g/dL (95% CI: 0.59-1.09), p < 0.001; (3) Decreased adverse reactions, pooled OR 0.35 (95% CI: 0.18-0.67), p = 0.001. Results were unchanged following sensitivity analyses. CONCLUSION: In this meta-analysis, IV iron is superior to oral iron for treatment of iron-deficiency anemia in pregnancy. Women receiving IV iron more often achieve desired hemoglobin targets, faster and with fewer side effects.

The Complement System and Preeclampsia.

PURPOSE OF REVIEW: Preeclampsia affects 3-4% of pregnancies with few treatment options to reduce maternal and fetal harm. Recent evidence that targeting the complement system may be an effective therapeutic strategy in prevention or treatment of preeclampsia will be reviewed. RECENT FINDINGS: Studies in humans confirm the safety and efficacy of C5 blockade in complement-mediated disorders of pregnancy, including preeclampsia. Animal models mimic the placental abnormalities and/or the maternal symptoms which characterize preeclampsia. These models in mouse and rat have defined a role for complement and its regulators in placental dysfunction, hypertension, proteinuria, endothelial dysfunction, fetal growth restriction, and angiogenic imbalance, thus informing future human studies. Targeting excessive complement activation, particularly the terminal complement complex (C5b-9) and C5a may be an effective strategy to prolong pregnancy in women with preeclampsia. Continued research is needed to identify the initiator(s) of activation, the pathways involved, and the key component(s) in the pathophysiology to allow development of safe and effective therapeutics to target complement without compromising its role in homeostasis and host defense.

Do Early Fetal Measurements and Nuchal Translucency Correlate With Term Birth Weight?

OBJECTIVE: Traditionally, physiological variation in fetal weight is believed to emerge during the latter half of pregnancy. Although recent evidence suggests that crown-rump length (CRL) and nuchal translucency (NT) measured at 11-14 weeks correlate with abnormal fetal growth, findings have been limited by dating accuracy in spontaneous gestations. Therefore, we sought to determine whether CRL or NT measurements correlated with term birth weight (BW) or BW ratio in a cohort of IVF pregnancies, in which the date of conception is precisely known. METHODS: This retrospective cohort study included 227 term, singleton IVF pregnancies. Subjects were included if they had an early first-trimester ultrasound examination and subsequent nuchal translucency (NT) screening. The difference between the measured and the expected CRL and the biparietal diameter (BPD) and NT measurement were calculated and correlated with the actual term BW or BW ratio. The BW ratio was calculated using the actual BW and the expected BW for GA. RESULTS: The difference between measured and expected mid-first-trimester CRL, and the BPD at NT assessment, correlated with BW ratio at delivery (rSpearman = 0.15, P = 0.023 and rSpearman = 0.27, P < 0.001, respectively). Absolute NT measurements and NT percentiles (adjusted for CRL) correlated with BW ratio at delivery (rSpearman = 0.18, r = 0.14, and P = 0.005 and 0.038, respectively). CONCLUSION: In this well-dated IVF population, we report a significant correlation between BW ratio and first-trimester CRL, BPD, and NT measurements. These findings support the hypothesis that physiological variation in BW can be reflected by variation in first-trimester fetal measurements.

The risk of fetal death in nonanomalous pregnancies affected by polyhydramnios.

OBJECTIVE: The objective of the study was to evaluate the ongoing risk of intrauterine fetal demise (IUFD) in nonanomalous pregnancies affected by polyhydramnios. STUDY DESIGN: We analyzed a retrospective cohort of all singleton, nonanomalous births in California between 2005 and 2008 as recorded in a statewide birth certificate registry. We included all births between 24+0 and 41+6 weeks' gestational age, excluding multiple gestations, major congenital anomalies, and pregnancies affected by oligohydramnios. Polyhydramnios was identified by International Classification of Diseases, ninth revision, codes. χ(2) tests were used to compare the dichotomous outcomes, and multivariable logistic regression analyses were then performed to control for potential confounders. We analyzed the data for pregnancies affected and unaffected by polyhydramnios. The IUFD risk was expressed as a rate per 10,000. RESULTS: The risk of IUFD in pregnancies affected by polyhydramnios was greater at every gestational age compared with unaffected pregnancies. The IUFD risk in pregnancies affected by polyhydramnios was more than 7 times higher than unaffected pregnancies at 37 weeks at a rate of 18.0 (95% confidence interval [CI], 9.0-32.6) vs 2.4 (95% CI, 2.0-2.5) and was 11-fold higher by 40 weeks' gestational age at a rate of 66.3 (95% CI, 10.8-68.6) vs 6.0 (95% CI, 5.1-6.3) in unaffected pregnancies. When adjusted for multiple confounding variables, the presence of polyhydramnios remained associated with an increased odds of IUFD in nonanomalous singleton pregnancies, with an adjusted odds ratio of 5.5 (95% CI, 4.1-7.6). CONCLUSION: Ongoing risk of IUFD is greater in low-risk pregnancies affected by polyhydramnios at all gestational ages compared with unaffected pregnancies with the greatest increase in risk at term. Although further study is needed to explore the underlying etiology of polyhydramnios in these cases, the identification of polyhydramnios alone may warrant increased antenatal surveillance.

Angiogenic Biomarkers in Preeclampsia.

Preeclampsia contributes disproportionately to maternal and neonatal morbidity and mortality throughout the world. A critical driver of preeclampsia is angiogenic imbalance, which is often present weeks to months before overt disease. Two placenta-derived angiogenic biomarkers, soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF), have proved useful as diagnostic and prognostic tests for preeclampsia. Recently, the U.S. Food and Drug Administration approved the sFlt-1/PlGF assay to aid in the prediction of preeclampsia with severe features among women with hypertensive disorders of pregnancy at 24-34 weeks of gestation. In this narrative review, we summarize the body of work leading to this approval and describe how the sFlt-1/PlGF ratio may be implemented in clinical practice as an adjunctive measure to help optimize care and to reduce adverse outcomes in preeclampsia.

Thrombotic Microangiopathies and the Kidney.

Thrombotic microangiopathy (TMA) is a pathological lesion that occurs due to endothelial injury. It can be seen in a heterogenous group of disorders, typically characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end-organ ischemia. TMA can also be renal limited with no systemic manifestations. There are multiple etiologies of a TMA with complement activation being a core underlying mechanism, although the nature and extent of complement involvement can vary. A further complicated factor is the cross talk between complement, neutrophils, and coagulation pathways in the pathophysiology of TMAs. Therefore, a thorough and systematic clinical history and laboratory evaluation are critical to establish the cause and pathophysiology of a TMA. Furthermore, TMAs are associated with significant morbidity and mortality, and timely diagnosis is key for appropriate management and to prevent end-stage kidney disease and other associated complications. In this review, we focus on the pathology, mechanisms, diagnostic work up and treatment of TMAs associated with various etiologies. We also define the complement evaluations that should be conducted in these patients and further highlight the currently approved complement therapies as well as others in the pipeline.

Thrombotic Microangiopathy in Pregnancy: Current Understanding and Management Strategies.

Thrombotic microangiopathy (TMA) represents a heterogeneous group of disorders characterized by microvascular thrombosis and end-organ damage. Pregnancy-associated thrombotic microangiopathy (p-TMA) has emerged as a distinct clinical entity with unique diagnostic challenges. Identifying the specific form of p-TMA is critical for appropriate and timely management. This review offers a comprehensive overview of the various forms of thrombotic microangiopathies associated with pregnancy, highlighting our current understanding of their pathophysiology and the evolving landscape of diagnosis and treatment for each.