Hypertension in CKD Pregnancy: a Question of Cause and Effect (Cause or Effect? This Is the Question)

The effect of preeclampsia on long-term kidney function among pregnant women with chronic kidney disease

BACKGROUND

The association between superimposed preeclampsia and an elevated risk of long-term kidney function decline or end-stage kidney disease (ESKD) in patients with chronic kidney disease (CKD) has not been determined. This study aimed to analyze the association between preeclampsia and kidney function deterioration in CKD patients.

METHODS

This was a retrospective cohort study that included the clinical information of 103 pregnant CKD patients with preeclampsia and 103 matched CKD patients without preeclampsia who were followed-up for a minimum of 1 year after their first pregnancy from 1 January 2009 to 31 May 2022. Robust Cox regression analysis was also conducted to evaluate the effects of preeclampsia on long-term kidney function decline or ESKD in CKD patients. Kaplan-Meier curves were used to compare renal survival within different subgroups via the log-rank test.

RESULTS

During the follow-up period, 44 (42.72%) CKD patients with preeclampsia and 20 (19.42%) without preeclampsia had an estimated glomerular filtration rate (eGFR) decrease >30% or developed ESKD. Compared with CKD patients without preeclampsia, the eGFR decreased more significantly in patients with preeclampsia [98.43 (79.48, 116.47) to 81.32 (41.20, 102.97) mL/min/1.73 m2 vs 99.43 (79.00, 118.50) to 89.44 (63.69, 105.30) mL/min/1.73 m2; P = .034]. The rate of eGFR decrease was more pronounced in patients with preeclampsia (17.38% vs 10.05%, P < .05). Multivariate analysis revealed that early-onset preeclampsia (preeclampsia that developed before 34 weeks of gestation) [hazard ratio (HR) = 2.61, 95% confidence interval (CI) 1.32-5.16, P = 0.006] and late-onset preeclampsia (HR = 2.54, 95% CI 1.34-4.83, P = .004) were both risk factors for an eGFR decrease >30% or ESKD.

CONCLUSION

Preeclampsia was associated with a greater risk of long-term kidney function decline or ESKD among CKD patients, especially in patients with early-onset preeclampsia.

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.

What a paediatric nephrologist should know about preeclampsia and why it matters

Preeclampsia is a protean syndrome causing a kidney disease characterised by hypertension and proteinuria, usually considered transitory and reversible after delivery. Its prevalence ranges from 3-5 to 10% if all the related disorders are considered. This narrative review, on behalf of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology, focuses on three reasons why preeclampsia should concern paediatric nephrologists and how they can play an important role in its prevention, as well as in the prevention of future kidney and cardiovascular diseases. Firstly, all diseases of the kidney and urinary tract diagnosed in paediatric age are associated with a higher risk of adverse pregnancy-related outcomes, including preeclampsia. Secondly, babies with low birth weights (small for gestational age, born preterm, or both) have an increased risk of developing the full panoply of metabolic diseases (obesity, hypertension, early-onset cardiopathy and chronic kidney disease) and girls are at higher risk of developing preeclampsia when pregnant. The risk may be particularly high in cases of maternal preeclampsia, highlighting a familial aggregation of this condition. Thirdly, pregnant teenagers have a higher risk of developing preeclampsia and the hypertensive disorders of pregnancy, and should be followed up as high risk pregnancies. In summary, preeclampsia has come to be seen as a window on the future health of both mother and baby. Identification of subjects at risk, early counselling and careful follow-up can contribute to reducing the high morbidity linked with this disorder.

Maternal and fetal outcomes of pregnancy in chronic kidney disease: diagnostic challenges, surveillance and treatment throughout the spectrum of kidney disease

Pregnancy requires several physiological adaptations from the maternal organism, including modifications in the glomerular filtration rate and renal excretion of several products. Chronic kidney disease (CKD) can negatively affect these modifications and consequently is associated with several adverse maternal and fetal adverse outcomes (gestational hypertension, progression of renal disease, pre-eclampsia, fetal growth restriction, and preterm delivery). A multidisciplinary vigilance of these pregnancies is essential in order to avoid and/or control the harmful effects associated with this pathology. Dialysis and transplantation can decrease the risks of maternal and fetal complications, nonetheless, the rates of complications remain high comparing with a normal pregnancy. Several recent developments in this area have improved quality and efficacy of treatment of pregnant women with CKD. This article summarizes the most recent literature about CKD and pregnancy.

Low-dose aspirin for the prevention of severe preeclampsia in patients with chronic kidney disease: a retrospective study : This is the study for kidney and pregnancy

OBJECTIVE

The objective of the study was to investigate the effects of low-dose aspirin (LDA) during pregnancy on the prevention of preeclampsia in patients with chronic kidney disease (CKD).

METHODS

The clinical data of pregnant women with CKD were retrospectively analyzed at Peking University First Hospital between January 2013 and January 2020. Among 287 pregnant women with stage 1-2 CKD, 63 patients who were treated with LDA were included in study group 1, and 63 patients who were not treated with aspirin were allocated to control group 1. Among 41 pregnant women with stage 3-5 CKD, 22 patients who were treated with LDA were included in study group 2, and 19 patients were allocated to control group 2. Pregnancy outcomes of the patients with stage 1-2 and stage 3-5 CKD who received LDA during pregnancy and those who did not were compared.

RESULTS

No significant difference was observed in the incidence of preeclampsia or severe preeclampsia between study and control group 1. The patients in study group 2 had a lower incidence of severe preeclampsia than those in control group 2 (3/22 [13.6%] vs. 8/19 [42.1%], P = 0.04). Among the patients with stage 3-5 CKD, LDA therapy during pregnancy was associated with a lower risk of severe preeclampsia (odds ratio = 0.22, 95% confidence interval: 0.074-0.993; P = 0.049).

CONCLUSIONS

LDA therapy during pregnancy can reduce the risk of severe preeclampsia in patients with stage 3-5 CKD. Prospective studies are  needed to further explore the preventive effects of aspirin on preeclampsia in patients with stage 1-2 CKD.

Successful pregnancy and delivery in uremic patients with maintenance hemodialysis: A case report

RATIONALE

It is reported that successful pregnancies in dialyzed uremic women are rare. Over the past years, despite advances in clinical management and technology in dialysis for pregnancy in patients receiving maintenance hemodialysis, uremia remains a high risk factor for adverse outcomes in mother and fetus.

PATIENT CONCERNS

In this article, we present a case of pregnancy in a 34-year-old uremic woman on dialysis. After the pregnancy was diagnosed and confirmed, intensive dialysis and multidisciplinary care according to the recommendations in the available literatures were provided.

DIAGNOSES

Single pregnancy of 31 GWs (gestational weeks), fetal growth restriction, polyhydramnios, and uremia.

OUTCOMES

At 31 weeks' gestation and 4 days, she was admitted to our hospital due to premature rupture of membranes and abdominal pain. Then a female baby weighed 1700 g was delivered successfully. After one year of follow-up, the mother feels well and the baby is healthy.

LESSONS

Intensive dialysis, detailed management and multidisciplinary approaches are necessary for optimal outcomes in uremic pregnant mother and fetus.

Pregnancy in Chronic Kidney Disease: Need for Higher Awareness. A Pragmatic Review Focused on What Could Be Improved in the Different CKD Stages and Phases

Pregnancy is possible in all phases of chronic kidney disease (CKD), but its management may be difficult and the outcomes are not the same as in the overall population. The prevalence of CKD in pregnancy is estimated at about 3%, as high as that of pre-eclampsia (PE), a better-acknowledged risk for adverse pregnancy outcomes. When CKD is known, pregnancy should be considered as high risk and followed accordingly; furthermore, since CKD is often asymptomatic, pregnant women should be screened for the presence of CKD, allowing better management of pregnancy, and timely treatment after pregnancy. The differential diagnosis between CKD and PE is sometimes difficult, but making it may be important for pregnancy management. Pregnancy is possible, even if at high risk for complications, including preterm delivery and intrauterine growth restriction, superimposed PE, and pregnancy-induced hypertension. Results in all phases are strictly dependent upon the socio-sanitary system and the availability of renal and obstetric care and, especially for preterm children, of intensive care units. Women on dialysis should be aware of the possibility of conceiving and having a successful pregnancy, and intensive dialysis (up to daily, long-hours dialysis) is the clinical choice allowing the best results. Such a choice may, however, need adaptation where access to dialysis is limited or distances are prohibitive. After kidney transplantation, pregnancies should be followed up with great attention, to minimize the risks for mother, child, and for the graft. A research agenda supporting international comparisons is highly needed to ameliorate or provide knowledge on specific kidney diseases and to develop context-adapted treatment strategies to improve pregnancy outcomes in CKD women.

A best-practice position statement on pregnancy after kidney transplantation: focusing on the unsolved questions. The Kidney and Pregnancy Study Group of the Italian Society of Nephrology

Kidney transplantation (KT) is often considered to be the method best able to restore fertility in a woman with chronic kidney disease (CKD). However, pregnancies in KT are not devoid of risks (in particular prematurity, small for gestational age babies, and the hypertensive disorders of pregnancy). An ideal profile of the potential KT mother includes "normal" or "good" kidney function (usually defined as glomerular filtration rate, GFR ≥ 60 ml/min), scant or no proteinuria (usually defined as below 500 mg/dl), normal or well controlled blood pressure (one drug only and no sign of end-organ damage), no recent acute rejection, good compliance and low-dose immunosuppression, without the use of potentially teratogen drugs (mycophenolic acid and m-Tor inhibitors) and an interval of at least 1-2 years after transplantation. In this setting, there is little if any risk of worsening of the kidney function. Less is known about how to manage "non-ideal" situations, such as a pregnancy a short time after KT, or one in the context of hypertension or a failing kidney. The aim of this position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology is to review the literature and discuss what is known about the clinical management of CKD after KT, with particular attention to women who start a pregnancy in non-ideal conditions. While the experience in such cases is limited, the risks of worsening the renal function are probably higher in cases with markedly reduced kidney function, and in the presence of proteinuria. Well-controlled hypertension alone seems less relevant for outcomes, even if its effect is probably multiplicative if combined with low GFR and proteinuria. As in other settings of kidney disease, superimposed preeclampsia (PE) is differently defined and this impairs calculating its real incidence. No specific difference between non-teratogen immunosuppressive drugs has been shown, but calcineurin inhibitors have been associated with foetal growth restriction and low birth weight. The clinical choices in cases at high risk for malformations or kidney function impairment (pregnancies under mycophenolic acid or with severe kidney-function impairment) require merging clinical and ethical approaches in which, beside the mother and child dyad, the grafted kidney is a crucial "third element".

The pregnancy outcomes in patients with stage 3-4 chronic kidney disease and the effects of pregnancy in the long-term kidney function

Objective

To investigate the pregnancy outcomes for patients with stage 3–4 chronic kidney disease (CKD) and the effects of pregnancy on kidney function.

Methods

Clinical data of pregnant women with CKD in the Peking University First Hospital between January 1st 2005 and October 1st 2016 were retrospectively analysed. The pregnancy outcomes of patients with different stages of CKD were compared. Patients with stage 3–4 CKD were followed up by telephone interview, and non-pregnant patients with stage 3–4 CKD were selected using the propensity score method to analyse the effects of pregnancy on kidney function.

Results

A total of 293 women with 300 pregnancies met the study criteria. There were 30 cases of stage 3–4 CKD. The incidence of adverse pregnancy outcomes of patients with stage 3–4 CKD was significantly higher than that with stage 1 CKD. The mean postpartum follow-up time of pregnant patients with CKD was 49.0 ± 33.1 months. A total of 26 cases of stage 3–4 CKD were followed up. During the follow-up period, 8 patients progressed to ESRD. A total of 28 non-pregnant patients with stage 3–4 CKD were selected as the control group. The results of multivariate analysis revealed that pregnancy did not increase the risk of deterioration of kidney function.

Conclusion

Patients with stage 3–4 CKD in early pregnancy had a significantly increased risk of adverse pregnancy outcomes. Pregnancy itself did not seem to accelerate kidney disease progression in patients with stage 3–4 CKD.

A best practice position statement on the role of the nephrologist in the prevention and follow-up of preeclampsia: the Italian study group on kidney and pregnancy

Preeclampsia (PE) is a protean syndrome causing a transitory kidney disease, characterised by hypertension and proteinuria, ultimately reversible after delivery. Its prevalence is variously estimated, from 3 to 5% to 10% if all the related disorders, including also pregnancy-induced hypertension (PIH) and HELLP syndrome (haemolysis, increase in liver enzyme, low platelets) are included. Both nephrologists and obstetricians are involved in the management of the disease, according to different protocols, and the clinical management, as well as the role for each specialty, differs worldwide. The increased awareness of the role of chronic kidney disease in pregnancy, complicating up to 3% of pregnancies, and the knowledge that PE is associated with an increased risk for development of CKD later in life have recently increased the interest and redesigned the role of the nephrologists in this context. However, while the heterogeneous definitions of PE, its recent reclassification, an emerging role for biochemical biomarkers, the growing body of epidemiological data and the new potential therapeutic interventions lead to counsel long-term follow-up, the lack of resources for chronic patients and the increasing costs of care limit the potential for preventive actions, and suggest tailoring specific interventional strategies. The aim of the present position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature and to try to identify theoretical and pragmatic bases for an agreed management of PE in the nephrological setting, with particular attention to the prevention of the syndrome (recurrent PE, presence of baseline CKD) and to the organization of the postpartum follow-up.