Pregnancy after living kidney donation, a systematic review of the available evidence, and a review of the current guidance

Evaluation of maternal and fetal outcomes in pregnancies with maternal solitary kidney: A case-control study from a tertiary center

INTRODUCTION

There exists a prevailing concern regarding the heightened susceptibility of women with a solitary kidney to unfavorable consequences during pregnancy. Irrespective of the underlying etiology, individuals with a solitary kidney are advised to have regular annual screenings for blood pressure and urinalysis due to their increased susceptibility to developing proteinuria, hypertension, and renal failure.

OBJECTIVE

To investigate the risk of adverse pregnancy outcomes in women with a maternal solitary kidney by comparing maternal and fetal outcomes to those of healthy pregnant women.

METHODS

This retrospective, single-center study was conducted with 29 pregnant women with maternal solitary kidney and 60 healthy controls at a tertiary hospital. Obstetric data such as gestational hypertension, preeclampsia, preterm labor, birth week, mode of delivery, Apgar scores, and neonatal intensive care requirements, were compared between the groups. A binary logistic regression analysis was performed to determine the obstetric complications increased by the presence of maternal solitary kidney.

RESULTS

The number of spontaneous abortions, serum creatinine and blood urea nitrogen levels were significantly higher in the patients with solitary kidney (p < 0.05). The birth week was earlier among the patients with a solitary kidney compared to the controls (p = 0.013). The preterm and cesarean delivery rates were also higher in the case group (p = 0.002 and p = 0.035, respectively). The pregnant women with solitary kidney were found to have higher rates of gestational hypertension, preeclampsia, and maternal intensive care requirements (p = 0.008, p = 0.015, and p = 0.008, respectively). Logistic regression analysis revealed a seven-fold increase in the rate of preterm labor (1.45-37.64) and a three-fold increase in preeclampsia (1.27-22.08) among the pregnant women with a solitary kidney.

CONCLUSION

Patients with solitary kidney are at high risk of encountering pregnancy complications, such as gestational hypertension, preeclampsia, and preterm labor. These pregnant women should be followed up carefully, starting from the first prenatal visit.

Living Donation and Pregnancy-Related Complications: State of the Evidence and Call To Action for Improved Risk Assessment

Living kidney donation and living liver donation significantly increases organ supply to make lifesaving transplants possible, offering survival benefits to the recipients and cost savings to society. Of all living donors, 40% are women of childbearing age. However, limited data exist regarding the effect of donation on future pregnancies and of pregnancy-related complications on postdonation outcomes. In February 2023, the American Society of Transplantation Women's Health Community of Practice held a virtual Controversies Conference on reproductive health, contraception, and pregnancy after transplantation and living donation. Experts in the field presented the available data. Smaller breakout sessions were created to discuss findings, identify knowledge gaps, and develop recommendations. We present the conference findings related to living donation. The evidence reviewed shows that gestational hypertension and gestational diabetes mellitus before kidney donation have been associated with an increased risk of developing postdonation hypertension and diabetes mellitus, respectively, without increasing the risk of developing an eGFR <45 ml/min after donation. The risk of preeclampsia in living kidney donors increases to 4%-10%, and low-dose aspirin may help reduce that risk. Little is known about the financial burden for living donors who become pregnant, their risk of postpartum depression, or the optimal time between donation and conception. The data on living liver donors are even scarcer. The creation of a registry of donor candidates may help answer many of these questions and, in turn, educate prospective donors so that they can make an informed choice.

Pregnancy Outcomes in Living Kidney Donors: Protocol of a Population-Based Cohort Study in Three Canadian Provinces

Background

A substantial proportion of living kidney donors are women of childbearing age. Some prior studies report a higher risk of gestational hypertension and pre-eclampsia in living kidney donors compared with nondonors. Further research is needed to better quantify the risk of adverse maternal, fetal/infant, and neonatal outcomes attributable to living kidney donation.

Objective

To determine the risk of hypertensive disorders of pregnancy, including gestational hypertension, pre-eclampsia, and eclampsia, and other maternal and fetal/infant outcomes in living kidney donors compared with a matched group of nondonors of similar baseline health.

Design and Setting

Protocol for a population-based, matched cohort study using Canadian administrative health care databases. The protocol will be run separately in 3 provinces, Ontario, Alberta, and British Columbia, and results will be combined statistically using meta-analysis.

Participants

The cohort will include women aged 18 to 48 years who donated a kidney between July 1992 and March 2022 and had at least one postdonation singleton pregnancy of ≥20 weeks gestation between January 1993 and February 2023. We expect to include at least 150 living kidney donors with over 200 postdonation pregnancies from Ontario and a similar number of donors and pregnancies across Alberta and British Columbia combined. Nondonors will include women from the general population with at least one pregnancy of ≥20 weeks gestation between January 1993 and February 2023. Nondonors will be randomly assigned cohort entry dates based on the distribution of nephrectomy dates in donors. The sample of nondonors will be restricted to those aged 18 to 48 years on their cohort entry dates with delivery dates at least 6 months after their assigned entry dates. A concern with donor and nondonor comparisons is that donors are healthier than the general population. To reduce this concern, we will also apply 30+ exclusion criteria to further restrict the nondonor group so that they have similar health measures at cohort entry as the donors. Donor and nondonor pregnancies will then be matched (1:4) on 5 potential confounders: delivery date, maternal age at delivery date, time between cohort entry and delivery date, neighborhood income quintile, and parity at delivery date.

Measurements

The primary outcome will be a composite of maternal gestational hypertension, preeclampsia, or eclampsia. Secondary maternal outcomes will include components of the primary outcome, early pre-eclampsia, severe maternal morbidity, cesarean section, postpartum hemorrhage, and gestational diabetes. Fetal/infant/neonatal outcomes will include premature birth/low birth weight, small for gestational age, neonatal intensive care unit admission, stillbirth, and neonatal death.

Methods

The primary unit of analysis will be the pregnancy. We will compute the risk ratio of the primary composite outcome in donors versus nondonors using a log-binomial mixed regression model with random effects to account for the correlation within women with multiple pregnancies and within matched sets of donors and nondonors. We will perform the statistical analyses within each province and then combine aggregated results using meta-analytic techniques to produce overall estimates of the study outcomes.

Limitations

Due to regulations that prevent individual-level records from being sent to other provinces, we cannot pool individual-level data from all 3 provinces.

Conclusion

Compared to prior studies, this study will better estimate the donation-attributable risk of adverse maternal, fetal/infant, and neonatal outcomes. Transplant centers can use the results to counsel female living donor candidates of childbearing age and to inform recommended practices for the follow-up and care of living kidney donors who become pregnant.

Evaluation and Long-Term Follow-Up of Living Kidney Donors

The evaluation of living kidney donor candidates is a complex and lengthy process. Donor candidates face geographic and socioeconomic barriers to completing donor evaluation. Inequities in access to living donations persist. With a growing demand for kidney transplants and a shortage of living donors, transplant centers are more permissive of accepting less-than-ideal donor candidates. Donors have an increased lifetime risk of kidney failure, but the absolute risk increase is small. Efforts are needed to support donor candidates to complete donor nephrectomy safely and efficiently and receive optimal follow-up care to prevent risk factors for kidney disease and detect complications early. In this article, the authors address key elements of donor kidney evaluation, including current living donation policy requirements and transplant center practices. The authors present a simplified comprehensive practical approach to help guide providers in completing donor evaluation and follow-up care with best outcomes possible.

Reproductive Health in Kidney Transplant Recipients

Increasing number of women with kidney transplants are of reproductive age and desire successful pregnancies. Successful outcomes of pregnancy can be achieved with preconception counseling, education about contraception use, the timing of pregnancy (delaying by first year post-transplant), and the choice of immunosuppression medication. Ensuring stable renal function including optimized creatinine, proteinuria, and blood pressure increases successful outcomes. Pregnancy with kidney transplant has an increased risk of preeclampsia, gestational diabetes militeus, cesarean section, and preterm delivery. Multidisciplinary cooperation with high-risk obstetrics and transplant nephrologists is vital.

Fenestrated Endothelial Cells across Organs: Insights into Kidney Function and Disease

In the human body, the vascular system plays an indispensable role in maintaining homeostasis by supplying oxygen and nutrients to cells and organs and facilitating the removal of metabolic waste and toxins. Blood vessels-the key constituents of the vascular system-are composed of a layer of endothelial cells on their luminal surface. In most organs, tightly packed endothelial cells serve as a barrier separating blood and lymph from surrounding tissues. Intriguingly, endothelial cells in some tissues and organs (e.g., choroid plexus, liver sinusoids, small intestines, and kidney glomerulus) form transcellular pores called fenestrations that facilitate molecular and ionic transport across the vasculature and mediate immune responses through leukocyte transmigration. However, the development and unique functions of endothelial cell fenestrations across organs are yet to be fully uncovered. This review article provides an overview of fenestrated endothelial cells in multiple organs. We describe their development and organ-specific roles, with expanded discussions on their contributions to glomerular health and disease. We extend these discussions to highlight the dynamic changes in endothelial cell fenestrations in diabetic nephropathy, focal segmental glomerulosclerosis, Alport syndrome, and preeclampsia, and how these unique cellular features could be targeted for therapeutic development. Finally, we discuss emerging technologies for in vitro modeling of biological systems, and their relevance for advancing the current understanding of endothelial cell fenestrations in health and disease.

Perspectives of relatives of patients with end-stage kidney disease on kidney sources, commercial kidney donation, and barriers to living kidney donation in Nigeria: a qualitative study

BACKGROUND

Kidney transplantation is the best mode of kidney replacement therapy. However, the shortage of organ donations has been a major challenge globally. Relatives of patients with end-stage kidney disease (ESKD) are potential kidney donors. We explored their perspectives about kidney donation, kidney commercialisation, and barriers to kidney donation.

METHODS

In-depth interviews were conducted among 28 relatives of ESKD patients across the six geopolitical zones and Federal Capital Territory of Nigeria. The interview focused on potential sources of kidney donors, kidney commercialisation and barriers to kidney donation. ATLAS.ti version 9.0.22.0 was used for data analysis.

RESULTS

Mean age of the study participants was 41.57 ± 14.55 years; 54% were females, 60.7% were married, 93% had tertiary education and 75% were first degree relatives of ESKD patients. There were 7 themes and 28 subthemes generated in this study. The potential sources of kidney donors identified by the study participants included commercial, hospital, family and non-family member donors. While some opined that a family member is the best choice as a kidney donor, others preferred a commercial donor. The majority of those interviewed do not believe that it is wrong to purchase a kidney, and would be willing to do so. Identified factors that promote kidney commercialisation were unwillingness of a family member to donate, having the financial capacity to purchase a kidney, non-fitness of family members to donate. Identified barriers to kidney donation were age, poor health status, polygamy, perceived poor expertise of the medical team, perceived risk of the procedure, parental influence and religious beliefs.

CONCLUSIONS

The majority of participants lacked correct information about kidney donation. Implementation of educational program policies and laws regulating and reinforcing ethical principles of kidney donation and transplantation should be ensured.

Any reduction in maternal kidney mass makes a difference during pregnancy in gestational and fetal outcome

Little is known about the effect tubulointerstitial nephropathies have in modulating maternal-fetal outcomes in pregnancy. Therefore, we analyzed the main outcomes of pregnancy in these women to gain a better understanding of the role of a reduction in maternal kidney mass. From the Torino Cagliari Observational Study (TOCOS) cohort, we selected 529 patients with a diagnosis of tubulointerstitial disease and focused on 421 patients with chronic kidney disease (CKD) stage 1, without hypertension but with proteinuria less than 0.5 g/day at referral. From a cohort of 2969 singleton deliveries from low-risk pregnancies followed in the same settings we selected a propensity score matched control cohort of 842 pregnancies match 2:1 for age, parity, body mass index, ethnicity, and origin. Time to delivery was significantly shorter in the study cohort 38.0 (Quartile 1-Quartile 3: 37.0-39.0) versus 39.0 (Q1-Q3 38.0-40.0) weeks, with respect to controls. Incidence of delivery of less than 37 gestational weeks significantly increased from controls (7.4%) to women with previous acute pyelonephritis (10.8%), other tubulointerstitial diseases (9.7%) and was the highest in patients with a single kidney (31.1%). Similarly, neonatal birthweight significantly and progressively decreased from controls (3260 g [Q1-Q3: 2980-3530]), previous acute pyelonephritis (3090 g [Q1-Q3: 2868-3405], other tubulointerstitial diseases (3110 g [Q1-Q3: 2840-3417]), and to solitary kidney (2910 g [Q1-Q3: 2480-3240]). Risk of developing preeclampsia was significantly higher in the CKD cohort (3.6% vs 1.7% in low-risk controls). Thus, even a small reduction in functional kidney mass, such as a pyelonephritic scar, is associated with a shorter duration of pregnancy and an increased risk of preterm delivery. The risk is proportional to the extent of parenchymal reduction and is highest in cases with a solitary kidney.

Pregnancy in Living Kidney Donors: An Evidence-Based Review

Purpose of review

To review the current studies and guidelines on the risk of adverse pregnancy outcomes in female kidney donors.

Recent findings

Living kidney donors include a significant amount of young women of child-bearing age. Safety and possible risks of pregnancy after donation are a concern for female kidney donor candidates. Many current studies indicate a higher risk of preeclampsia in women after kidney donation. Considering the increasing number of living kidney donors, the maternal outcomes of living kidney donation is an active area of research.

Summary

Guidelines and consensus statements on the risk of pregnancy in living kidney donors recommend close monitoring of blood pressure, weight gain, and proteinuria during pregnancy. Current studies indicate an increased risk of hypertensive disorders of pregnancy in living kidney donors. Counseling and informing donor candidates about the possible risks is important.

A critique of whole body gestational donation

In her controversial paper, Anna Smajdor proposes that brain-dead people could be used as gestation units for prospective parents unable or unwilling to undertake the act themselves-what she terms whole body gestational donation (WBGD). She explores the ethical issues of such an idea and, comparing it with traditional organ donation, asserts that such deceased surrogacy could be a way of outsourcing pregnancy's harms to a populace unable to be affected by them. She argues that if the prospect is unacceptable, this may reveal some underlying problems with traditional cadaveric organ donation. Smajdor's analysis, however, overlooks several problems arising from WBGD. This paper provides an account of those issues and argues that, in addition to WBGD being viscerally unpleasant, it is also ethically unviable. The paper starts by providing an account of WBGD before acknowledging its negative response within traditional and social media. After arguing that such cursory and gut reactions are insufficient to reject the proposal outright, this paper then provides three concerns regarding WBGD omitted by Smajdor: (i) the co-opting of life-saving organs for reproduction, (ii) the discrepancy between using cadaveric organs to save a life versus creating one, and (iii) the universalization of feminist concerns regarding reproductive body commodification. The paper concludes by tentatively agreeing with Smajdor that considering WBGD may help reveal vulnerable assumptions regarding organ donation and surrogacy, but that the significant ethical issues raised may prove insurmountable and make the intervention-thought experiment or otherwise-untenable.

Long-term Outcomes Associated With Post-kidney Donation Pregnancy Complications

BACKGROUND

Kidney donors have increased risk of postdonation gestational hypertension (gHTN) and preeclampsia. In the general population, pregnancy complications are associated with long-term maternal risk. However, little data exist on whether donors with postdonation pregnancy-related complications have similar increased long-term risks. We studied whether postdonation gHTN, preeclampsia/eclampsia, or gestational diabetes (gDM) was associated with increased risk of developing hypertension, DM, cardiovascular disease, or estimated glomerular filtration rate <45 mL/min/1.73 m 2 .

METHODS

Postdonation pregnancies with complications were matched to pregnancies without complications based on time from donation. Incidence of outcomes was compared using sequential Cox regression with robust standard errors. Donors with predonation pregnancy complications were excluded. Models were adjusted for age at pregnancy, gravidity, year of donation, and family history of hypertension, DM, and heart disease.

RESULTS

Of the 384 donors with postdonation pregnancies (median [quartiles] follow-up of 27.0 [14.2-36.2] y after donation), 39 experienced preeclampsia/eclampsia, 29 gHTN without preeclampsia, and 17 gDM. Median interval from donation to first pregnancy with preeclampsia was 5.1 (2.9-8.6) y; for gHTN, 3.7 (1.9-7.8) y; and for gDM, 7.3 (3.7-10.3) y. Preeclampsia/eclampsia (hazard ratio [HR] 2.70; 95% confidence interval [CI], 1.53-4.77) and gHTN (HR 2.39; 95% CI, 1.24-4.60) were associated with development of hypertension. Preeclampsia/eclampsia (HR 2.15; 95% CI, 1.11-4.16) and gDM (HR 5.60; 95% CI, 1.41-22.15) were associated with development of DM. Pregnancy-related complications were not associated with increased risk of cardiovascular disease or estimated glomerular filtration rate <45 mL/min/1.73 m 2 .

CONCLUSIONS

In our single-center study, postdonation preeclampsia, gHTN, or gDM was associated with long-term risk of hypertension or DM.

Long-Term Kidney and Maternal Outcomes After Pregnancy in Living Kidney Donors

For counseling it is important to know if pregnancy after Living Kidney Donation (LKD) affects long-term outcomes of the mono-kidney and the mother. Therefore, we performed a retrospective multicenter study in women ≤45 years who donated their kidney between 1981 and 2017. Data was collected via questionnaires and medical records. eGFR of women with post-LKD pregnancies were compared to women with pre-LKD pregnancies or nulliparous. eGFR before and after pregnancy were compared in women with post-LKD pregnancies. Pregnancy outcomes post-LKD were compared with pre-LKD pregnancy outcomes. 234 women (499 pregnancies) were included, of which 20 with pre- and post-LKD pregnancies (68) and 26 with only post-LKD pregnancies (59). Multilevel analysis demonstrated that eGFR was not different between women with and without post-LKD pregnancies (p = 0.23). Furthermore, eGFR was not different before and after post-LKD pregnancy (p = 0.13). More hypertensive disorders of pregnancy (HDP) occurred in post-LKD pregnancies (p = 0.002). Adverse fetal outcomes did not differ. We conclude that, despite a higher incidence of HDP, eGFR was not affected by post-LKD pregnancy. In line with previous studies, we found an increased risk for HDP after LKD without affecting fetal outcome. Therefore, a pregnancy wish alone should not be a reason to exclude women for LKD.

Infertility, pregnancy and breastfeeding in kidney transplantation recipients: Key issues

Chronic kidney disease (CKD), especially in advanced stages, is an important cause of infertility. In CKD patients, infertility has been linked to multiple factors. The pathophysiology of infertility related to CKD is complex and forked. Correction of modifiable factors can improve fertility in both genders. In males as well as females, successful kidney transplantation offers good chances of restoration of reproductive function. In female renal allograft recipients, recovery of reproductive functions in the post-transplant period will manifest as restoration of normal menses and ovulation. Owing to this improvement, there is a significant risk of unplanned pregnancy, hence the need to discuss methods of contraception before transplantation. In kidney transplant recipients, different contraceptive options for pregnancy planning, have been used. The selection of one contraception over another is based on preference and tolerability. Pregnancy, in renal transplanted females, is associated with physiologic changes that occur in pregnant women with native kidneys. Immunosuppressive medications during pregnancy, in a recipient with a single functioning kidney, expose the mother and fetus to unwanted complications. Some immunosuppressive drugs are contraindicated during pregnancy. Immunosuppressive medications should be discussed with renal transplant recipients who are planning to breastfeed their babies. In addition to antirejection drugs, other medications should be managed accordingly, whenever pregnancy is planned.

Podocytopathy Associated with IgA Nephropathy in Pregnancy: A Challenging Association

IgA nephropathy is the most common form of primary glomerulonephritis. While associations of IgA and other glomerular diseases have been described, the association of IgA nephropathy with "primary" podocytopathy is rare and has not been reported in pregnancy, due in part to the infrequent use of kidney biopsy during pregnancy, and a frequent overlap with preeclampsia. We report the case of a 33-year-old woman with normal kidney function, referred in the 14th gestational week of her second pregnancy, due to nephrotic proteinuria and macroscopic hematuria. The baby's growth was normal. The patient reported episodes of macrohematuria one year previously. A kidney biopsy performed at 18 gestational weeks confirmed IgA nephropathy, associated with extensive podocyte damage. Treatment with steroids and tacrolimus led to remission of proteinuria and a healthy baby, adequate for gestational age, was delivered at 34 gestational weeks and 6 days (premature rupture of membranes). Six months after delivery, proteinuria was about 500 mg per day, with normal blood pressure and kidney function. This case highlights the importance of timely diagnosis in pregnancy and underlines that good maternal and fetal outcomes can be achieved with appropriate treatment, even in complex or severe cases.

Pregnancy outcomes after living kidney donation from a nationwide population-based cohort study from Korea

While most living kidney donors experience good outcomes and high rates of satisfaction, kidney donation can increase the risk of gestational hypertension or preeclampsia. However, pregnancy outcomes in non-white donors are limited. We conducted a nationwide cohort study of 112 living kidney donors and 672 matched healthy non-donors using the Korean National Health Insurance Claims Database. Donors and healthy non-donors were matched according to age, year of cohort entry, residency, income, number of pregnancies, and the time to the first pregnancy after cohort entry. We assessed pregnancy outcomes of live kidney donors compared with matched healthy non-donors using the nationwide database. Gestational hypertension or preeclampsia was more common in kidney donors than in non-donors (8.9% vs. 1.8%; adjusted odds ratio, 2.68; 95% confidence interval, 1.11-6.50). However, the incidence of severe gestational hypertension or preeclampsia that required antihypertensive medication was comparable (2.7% vs. 0.9%; P = 0.121). The time from donation to delivery within 5 years and primiparity were risk factors for preeclampsia in donors. Low birth weight, stillbirth, and ectopic pregnancy were not significantly different between the two groups. Maternal death occurred in two non-donor cases, but none occurred in donors compared to non-donors. Our findings indicate that kidney donors are associated with an increased risk of gestational hypertension or preeclampsia than matched healthy non-donors. However, the probabilities of serious maternal and fetal outcomes remained low and are not increased significantly after kidney donation.