Examination of Prepregnancy and Pregnancy Urinary Protein Levels in Healthy Nulliparous Women

Twenty-four-hour proteinuria levels are associated with adverse pregnancy outcomes among women with CKD

Background

Proteinuria is commonly measured to assess the renal status of chronic kidney disease (CKD) patients before the 20th week of gestation during pregnancy. High levels of proteiuria have been associated with adverse pregnancy outcomes. However, researchers have not clearly determined what baseline proteinuria levels would be associated with adverse pregnancy outcomes. This study aimed to analyse associations between proteinuria levels and adverse pregnancy outcomes among CKD patients treated with or without steroids/immunosuppressive therapy in early pregnancy.

Methods

This retrospective study included the clinical information of 557 pregnant patients with CKD from 1 January 2009 to 31 December 2021. A multivariable logistic regression analysis was conducted to evaluate the risk of adverse pregnancy outcomes across various proteinuria ranges, which were further stratified by whether the patients were receiving steroids/immunosuppressive therapy.

Results

(i) Proteinuria was assessed on 24-h urine collection. The median (quartile) baseline proteinuria levels were 0.83 g (0.20, 1.92) and 0.25 g (0.06, 0.80) in the steroids/immunosuppressive therapy and therapy-free groups, respectively. (ii) CKD patients with adverse pregnancy outcomes had significantly higher proteinuria levels in the first trimester than patients without adverse pregnancy outcomes. (iii) The risk of adverse pregnancy outcomes increased with increasing baseline proteinuria levels (P < .001). (iv) In the early-pregnancy steroids/immunosuppressive therapy group, the risk of severe preeclampsia was higher in patients with higher baseline proteinuria levels (P < .007) [odds ratio (OR) 30.86 for proteinuria ≥5.00 g/24 h]; in the therapy-free group, the risks of severe preeclampsia, very-low-birth-weight infants, early preterm birth and foetal-neonatal death were higher in patients with higher baseline proteinuria levels (OR 53.16 for proteinuria ≥5.00 g/24 h; OR 37.83 for proteinuria ≥5.00 g/24 h; OR 15.30 for proteinuria ≥5.00 g/24 h; and OR 18.83 for proteinuria ≥5.00 g/24 h, respectively; P < .001, P < .001, P < .001 and P = .006, respectively).

Conclusions

As shown in the present study, a baseline 24-h proteinuria level >1.00 g was associated with adverse maternal outcomes. Furthermore, a 24-h proteinuria level >2.00 g increased the incidence of adverse foetal events among CKD patients.

Optimal management of ANCA-associated vasculitis before and during pregnancy: current perspectives

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of systemic vasculitis characterized by autoantibodies against neutrophil cytoplasmic antigens (proteinase 3 PR3-ANCA and myeloperoxidase MPO-ANCA) and inflammation of small vessels. AAV include the diagnosis Granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA), which share many clinical and pathological features. Immunomodulatory therapies have significantly improved prognosis during the last decade. Nevertheless, especially in undiagnosed and thus uncontrolled AAV mortality due to renal impairment or pulmonary haemorrhages is still high. AAV are rare in fertile women, as the typical age of manifestation is above 50 years but there are women with AAV who are or want to become pregnant. This review focusses on how to manage patients with AAV planning to become pregnant and during their pregnancy.

Second-Trimester Constituents of the Metabolic Syndrome and Pregnancy Outcome: An Observational Cohort Study

Background: Gestational diabetes mellitus (GDM) increases the risk of type 2 diabetes mellitus and cardiovascular disease (CVD) in women in later life. In the general population, metabolic syndrome (MetS) shows identical associations. The aim of this study was to evaluate the association between GDM, constituents of MetS and pregnancy outcomes. Methods: Of 2041 pregnant women undergoing an oral glucose tolerance test (OGTT) between 22 and 30 weeks of gestation, data were collected to evaluate the constituents of MetS. Odds ratios (ORs) were calculated to determine the associations between MetS and pregnancy outcomes. Results: GDM and obesity did not affect the risk of fetal growth abnormalities (SGA/LGA), preterm birth or preeclampsia (PE). Hypertension significantly increased the risk of SGA (OR—1.59), PE (OR—3.14), and preterm birth <37 weeks (OR—2.17) and <34 weeks (OR—2.96) and reduced the occurrence of LGA (OR—0.46). Dyslipidemia increased the risk of PE (OR—2.25), while proteinuria increased the risk of PE (OR—12.64) and preterm birth (OR—4.72). Having ≥2 constituents increased the risk of PE and preterm birth. Conclusions: Constituents of metabolic syndrome, rather than treating impaired glucose handling, increased the risk of preeclampsia, altered fetal growth and preterm birth. Obesity was not related to adverse outcomes.

Proteinuria during pregnancy: definition, pathophysiology, methodology, and clinical significance

Qualitative and quantitative measurement of urine protein excretion is one of the most common tests performed during pregnancy. For more than 100 years, proteinuria was necessary for the diagnosis of preeclampsia, but recent guidelines recommend that proteinuria is sufficient but not necessary for the diagnosis. Still, in clinical practice, most patients with gestational hypertension will be diagnosed as having preeclampsia based on the presence of proteinuria. Although the reference standard for measuring urinary protein excretion is a 24-hour urine collection, spot urine protein-to-creatinine ratio is a reasonable "rule-out" test for proteinuria. Urine dipstick screening for proteinuria does not provide any clinical benefit and should not be used to diagnose proteinuria. The classic cutoff cited to define proteinuria during pregnancy is a value of >300 mg/24 hours or a urine protein-to-creatinine ratio of at least 0.3. Using this cutoff, the rate of isolated proteinuria in pregnancy may reach 8%, whereas preeclampsia occurs among 3% to 8% of pregnancies. Although this threshold is widely accepted, its origin is not based on evidence on adverse pregnancy outcomes but rather on expert opinion and results of small studies. After reviewing the available data, the most important factor that influences maternal and neonatal outcome is the severity of blood pressures and presence of end organ damage, rather than the excess protein excretion. Because the management of gestational hypertension and preeclampsia without severe features is almost identical in frequency of surveillance and timing of delivery, the separation into 2 disorders is unnecessary. If the management of women with gestational hypertension with a positive assessment of proteinuria will not change, we believe that urine assessment for proteinuria is unnecessary in women who develop new-onset blood pressure at or after 20 weeks' gestation. Furthermore, we do not recommend repeated measurement of proteinuria for women with preeclampsia, the amount of proteinuria does not seem to be related to poor maternal and neonatal outcomes, and monitoring proteinuria may lead to unindicated preterm deliveries and related neonatal complications. Our current diagnosis of preeclampsia in women with chronic kidney disease may be based on a change in protein excretion, a baseline protein excretion evaluation is critical in certain conditions such as chronic hypertension, diabetes, and autoimmune or other renal disorders. The current definition of superimposed preeclampsia possesses a diagnostic dilemma, and it is unclear whether a change in the baseline proteinuria reflects another systemic disease such as preeclampsia or whether women with chronic disease such as chronic hypertension or diabetes will experience a different "normal" pattern of protein excretion during pregnancy. Finally, limited data are available regarding angiogenic and other biomarkers in women with chronic kidney disease as a potential aid in distinguishing the worsening of baseline chronic kidney disease and chronic hypertension from superimposed preeclampsia.

The evolution of the diagnostic criteria of preeclampsia-eclampsia

As the understanding of the pathophysiology of preeclampsia has improved, its diagnostic criteria have evolved. The classical triad of hypertension, edema, and proteinuria has become hypertension and organ dysfunction-renal, hepatic, neurologic, hematological, or uteroplacental. However, the most recent definitions have largely been based off consensus and expert opinion, not primary research. In this review, we explore how the criteria have evolved, particularly through the second half of the 20^th and the beginning of the 21st century and offer a critical appraisal of the evidence that has led the criteria to where they stand today. Some key themes are the following: the debate between having a simple and convenient blood pressure cutoff vs a blood pressure cutoff that accounts for influencing factors such as age and weight; whether a uniform blood pressure threshold, a rise in blood pressure, or a combination is most discriminatory; whether existing evidence supports blood pressure and proteinuria thresholds in diagnosing preeclampsia; and whether using flow-charts and decision trees might be more appropriate than a single set of criteria. We also discuss the future of a preeclampsia diagnosis. We challenge the move toward a broad (vs restrictive) diagnosis, arguing instead for criteria that directly relate to the prognosis of preeclampsia and the response to treatments.

Physiological changes in pregnancy and their influence on the endocrine investigation

BACKGROUND

Physiological changes in pregnancy may result in significant alterations in endocrine hormone profiles, serum and urine electrolytes and endocrine gland morphology on imaging. Pregnancy-specific pathophysiological processes may also affect the results for endocrine tests. Investigation of endocrine disorders in pregnancy requires knowledge of these changes and awareness of the safety of dynamic hormone testing and imaging for the mother and foetus.

OBJECTIVE

This review seeks to outline the important physiological changes in pregnancy affecting reference intervals of basal and dynamic endocrine tests in pregnancy and the scenarios in which these changes are clinically significant, the pregnancy-specific disorders that may affect the investigation of endocrine disorders, and the safety of dynamic testing and imaging.

CONCLUSION

Awareness of the effect of physiological changes, and the potential impact of pregnancy-specific disorders of endocrine tests, and the safety of imaging is crucial to the management of endocrine disorders in pregnancy.

Changes of serum immunoglobulin level in healthy pregnant women and establishment of its reference interval

OBJECTIVES

Pregnant women in a special physiological period, the body's blood indicators will change to a certain extent. This study aims to explore the changes of serum immunoglobulin levels in healthy pregnant women and establish its reference interval (RI).

METHODS

A total of 369 healthy pregnant women, who underwent pregnancy examination in the Department of Obstetrics, Second Xiangya Hospital of Central South University from August 2019 to October 2019, were enrolled for this study. They were divided into an early pregnancy group, a middle pregnancy group, and a late pregnancy group according to the pregnancy period, and 123 healthy non-pregnant women were selected as the controls. The levels of immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) were determined by immune transmission turbidities. The level of immunoglobulin E (IgE) was determined by electrochemiluminescence. The differences in immunoglobulin levels between pregnant women and non-pregnant women and among different gestational periods were analyzed, and the RI of serum immunoglobulin level during pregnancy was established.

RESULTS

Compared to the non-pregnant women, the levels of serum IgG, IgM, IgA, and IgE in pregnant women were significantly decreased (all P<0.01), with 51.81% for IgG, 43.84% for IgM, 55.80% for IgA, and 49.80% for IgE. Except that the IgG level of late pregnancy group was significantly lower than that of early pregnancy group (P<0.05), there were no significant differences in the IgG, IgM, IgA, and IgE levels among the other groups (all P>0.05). The RIs of serum IgG in early pregnancy, middle pregnancy, and late pregnancy were 6.02-7.70 g/L, 5.18-6.85 g/L, and 4.58-5.72 g/L, respectively, while the RIs of serum IgM, IgA, and IgE were 0.71-0.93 g/L, 0.90-1.09 g/L, and 68.30-107.69 ng/mL, respectively in pregnant women.

CONCLUSIONS

The levels of immunoglobulin in pregnant women are decreased significantly. The establishment of RIs of IgG, IgM, IgA and IgE in healthy pregnant women could provide scientific basis for clinical decision-making.

Urinary Reference Values and First Insight into the Urinary Proteome of Captive Giraffes

Urinalysis is widely recognized to be a useful tool in routine health investigations, since it can diagnose numerous pathologies. Considering the paucity of knowledge concerning giraffes, urine from 44 giraffes (Giraffa camelopardalis) (18 males and 26 females, from 3 months of age to 21 years of age) underwent routine urinalysis, 1D-electrophoresis, and protein identification using mass spectrometry, with the aim of identifying the urinary reference values and the urine proteome. The urine specific gravity (USG), urine total proteins (uTP), urine creatinine (uCr), and urine protein:creatinine ratio (UPC) reference values, reported as the median, and lower limit (LL) and upper limit (UL), were 1.030 (1006-1.049), 17.58 (4.54-35.31) mg/dL, 154.62 (39.59-357.95) mg/dL, and 0.11 (0.07-0.16), respectively. Mass spectrometry, together with electrophoresis, revealed a pattern of common urinary proteins; albumin, lysozyme C, and ubiquitin were the most represented proteins in the giraffe urine. It has been hypothesized that these proteins could act as a defense against microbes. Moreover, in giraffes, urinalysis could be a valid tool for gauging renal function and physiological status changes.

Changes in proteinuria and diagnosing preeclampsia in CKD pregnancy

The diagnosis of preeclampsia superimposed on underlying kidney disease is complicated by physiological changes in renal function, blood pressure and proteinuria during pregnancy. Previous studies have demonstrated a significant increase in proteinuria during pregnancy in women with diabetic nephropathy in the absence of superimposed preeclampsia. There is a paucity of studies addressing changes in proteinuria during pregnancy in other conditions causing chronic kidney disease. A retrospective audit of changes in urine protein:creatinine ratios in 68 pregnancies to women with preconception proteinuria was performed, to determine whether changes in proteinuria may be useful in diagnosing preeclampsia. A 100% or greater increase in proteinuria from baseline increase was regarded as a significant change. In 51 pregnancies (75%) the peak urine protein:creatinine ratio did not rise significantly from values at the start of pregnancy. Where a greater than doubling of urine protein:creatinine ratio was seen, 12 of 17 pregnancies (70%) were judged clinically to have superimposed preeclampsia A significant increase in proteinuria also occurred in 3 women with lupus nephritis, and 2 with diabetic nephropathy, in the absence of preeclampsia. Larger studies of women with chronic kidney disease would be important to determine whether changes in proteinuria during pregnancy may be of diagnostic value for superimposed preeclampsia.

Spot urine protein measurements in normotensive pregnancies, pregnancies with isolated proteinuria and preeclampsia

We performed a prospective, longitudinal study of pregnant women presenting to their first obstetrics visits to characterize the changes in spot urine protein-to-creatinine (UPCR) and albumin-to-creatinine ratios (UACR) in normotensive pregnancies, as well as identify clinical characteristics associated with isolated proteinuria and preeclampsia. We measured spot urinary albumin, protein, and creatinine at the first prenatal visit, end of the second trimester, and at delivery. In the normotensive pregnancies (n = 142), we found that from the beginning of pregnancy to delivery, UACR increased by a median [interquartile range (IQR)] of 14.7 mg/g Cr (3.74-51.8) and UPCR by 60 mg/g Cr (30-130) (P < 0.001 for both changes). Isolated proteinuria (defined as UPCR > 300 mg/g Cr in the absence of hypertension) was identified in 19/142 (13.4%) normotensive pregnancies. Increases in systolic and diastolic blood pressure from early pregnancy to delivery and increases in UACR from early to midpregnancy were associated with isolated proteinuria at delivery. Twelve women developed preeclampsia. Nulliparity, early, and midpregnancy diastolic blood pressures were strongly associated with the development of preeclampsia, but early changes in UACR were not. In conclusion, women who develop isolated proteinuria at delivery have a larger increase in blood pressure than women without proteinuria and have a "microalbuminuric" phase earlier in gestation, unlike women who develop preeclampsia. These findings suggest a different mechanism of urine protein excretion in women with isolated proteinuria as compared with women with preeclampsia, where proteinuria has a more abrupt onset.