Pregnancy outcomes after kidney graft in Italy: are the changes over time the result of different therapies or of different policies? A nationwide survey (1978–2013)

Pregnancy outcomes in renal transplant recipients: A systematic review and meta-analysis

BACKGROUND

Kidney transplantation is a superior treatment for end-stage renal disease (ESRD), compared with hemodialysis, offering better quality of life and birth outcomes in women with ESRD and lower fertility rates.

OBJECTIVES

To investigate the pregnancy, maternal, fetal, and graft outcomes following kidney transplantation in women with ESRD and evaluate the improvements in quality of life and associated risks.

DESIGN

A systematic review and meta-analysis performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-analysis of Observational Studies in Epidemiology guidelines.

DATA SOURCES AND METHODS

A thorough search of multiple databases, including PubMed, Embase, Scopus, ATC abstracts, and Cochrane Central Register of Controlled Trials, was conducted to identify studies that analyzed pregnancy outcomes in kidney transplant patients. The search was conducted from the inception of each database to January 2023.

RESULTS

The study reviewed 109 studies that evaluated 7708 pregnancies in 5107 women who had undergone renal transplantation. Of these, 78.48% resulted in live births, 9.68% had induced abortion, and 68.67% had a cesarean section. Miscarriage occurred in 12.54%, preeclampsia in 20.87%, pregnancy-induced hypertension in 24.30%, gestational diabetes in 5.08%, and preterm delivery in 45.30% of cases. Of the 853 recipients, 123 had graft loss after pregnancy and 8.06% suffered acute rejection.

CONCLUSION

Pregnancy after kidney transplantation is associated with risks for mother and fetus; however, live births are still possible. In addition, there are reduced overall risks of stillbirths, miscarriages, neonatal deaths, and gestational diabetes.

REGISTRATION

PROSPERO (CRD42024541659).

Chronic kidney disease, female infertility, and medically assisted reproduction: a best practice position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology

Fertility is known to be impaired more frequently in patients with chronic kidney disease than in the general population. A significant proportion of chronic kidney disease patients may therefore need Medically Assisted Reproduction. The paucity of information about medically assisted reproduction for chronic kidney disease patients complicates counselling for both nephrologists and gynaecologists, specifically for patients with advanced chronic kidney disease and those on dialysis or with a transplanted kidney. It is in this context that the Project Group on Kidney and Pregnancy of the Italian Society of Nephrology has drawn up these best practice guidelines, merging a literature review, nephrology expertise and the experience of obstetricians and gynaecologists involved in medically assisted reproduction. Although all medically assisted reproduction techniques can be used for chronic kidney disease patients, caution is warranted. Inducing a twin pregnancy should be avoided; the risk of bleeding, thrombosis and infection should be considered, especially in some categories of patients. In most cases, controlled ovarian stimulation is needed to obtain an adequate number of oocytes for medically assisted reproduction. Women with chronic kidney disease are at high risk of kidney damage in case of severe ovarian hyperstimulation syndrome, and great caution should be exercised so that it is avoided. The higher risks associated with the hypertensive disorders of pregnancy, and the consequent risk of chronic kidney disease progression, should likewise be considered if egg donation is chosen. Oocyte cryopreservation should be considered for patients with autoimmune diseases who need cytotoxic treatment. In summary, medically assisted reproduction is an option for chronic kidney disease patients, but the study group strongly advises extensive personalised counselling with a multidisciplinary healthcare team and close monitoring during the chosen medically assisted reproduction procedure and throughout the subsequent pregnancy.

Glomerular diseases in pregnancy: pragmatic recommendations for clinical management

Our understanding of the various aspects of pregnancy in women with kidney diseases has significantly improved in the last decades. Nevertheless, little is known about specific kidney diseases. Glomerular diseases are not only a frequent cause of chronic kidney disease in young women, but combine many challenges in pregnancy: immunologic diseases, hypertension, proteinuria, and kidney tissue damage. An international working group undertook the review of available current literature and elicited expert opinions on glomerular diseases in pregnancy with the aim to provide pragmatic information for nephrologists according to the present state-of-the-art knowledge. This work also highlights areas of clinical uncertainty and emphasizes the need for further collaborative studies to improve maternal and fetal health.

A nationwide Dutch cohort study shows relatively good pregnancy outcomes after kidney transplantation and finds risk factors for adverse outcomes

Although numbers of pregnancy after kidney transplantation (KT) are rising, high risks of adverse pregnancy outcomes (APO) remain. Though important for pre-conception counselling and pregnancy monitoring, analyses of pregnancy outcomes after KT per pre-pregnancy estimated glomerular filtration rate-chronic kidney disease (eGFR-CKD)-categories have not been performed on a large scale before. To do this, we conducted a Dutch nationwide cohort study of consecutive singleton pregnancies over 20 weeks of gestation after KT. Outcomes were analyzed per pre-pregnancy eGFR-CKD category and a composite APO (cAPO) was established including birth weight under 2500 gram, preterm birth under 37 weeks, third trimester severe hypertension (systolic blood pressure over 160 and/or diastolic blood pressure over 110 mm Hg) and/or over 15% increase in serum creatinine during pregnancy. Risk factors for cAPO were analyzed in a multilevel model after multiple imputation of missing predictor values. In total, 288 pregnancies in 192 women were included. Total live birth was 93%, mean gestational age 35.6 weeks and mean birth weight 2383 gram. Independent risk factors for cAPO were pre-pregnancy eGFR, midterm percentage serum creatinine dip and midterm mean arterial pressure dip; odds ratio 0.98 (95% confidence interval 0.96-0.99), 0.95 (0.93-0.98) and 0.94 (0.90-0.98), respectively. The cAPO was a risk indicator for graft loss (hazard ratio 2.55, 1.09-5.96) but no significant risk factor on its own when considering pre-pregnancy eGFR (2.18, 0.92-5.13). This was the largest and most comprehensive study of pregnancy outcomes after KT, including pregnancies in women with poor kidney function, to facilitate individualized pre-pregnancy counselling based on pre-pregnancy graft function. Overall obstetric outcomes are good. The risk of adverse outcomes is mainly dependent on pre-pregnancy graft function and hemodynamic adaptation to pregnancy.

Follow-Up of Offspring Born to Parents With a Solid Organ Transplantation: A Systematic Review

Pregnancy after solid organ transplantation (SOT) has potential risks for the offspring. Most existing research focused on short-term pregnancy outcomes. The aim of this systematic review was to evaluate available data concerning longer term outcomes (>1 year) of these children. A systematic literature search, following PRISMA guidelines, of PubMed and Embase was performed from the earliest date of inception through to 6th April 2022. Publications on all types of (combined) SOT were eligible for inclusion. In total, 53 articles were included. The majority assessed offspring after kidney (78% of offspring) or liver transplantation (17% of offspring). 33 studies included offspring aged >4 years and five offspring aged >18 years. One study was included on fathers with SOT. The majority of the 1,664 included children after maternal SOT had normal intellectual, psychomotor, and behavioral development. Although prematurity and low birth weight were commonly present, regular growth after 1 year of age was described. No studies reported opportunistic or chronic infections or abnormal response to vaccinations. In general, pregnancy after SOT appears to have reassuring longer term outcomes for the offspring. However, existing information is predominantly limited to studies with young children. Longer prospective studies with follow-up into adulthood of these children are warranted.

Planned Pregnancy in Kidney Transplantation. A Calculated Risk

Pregnancy is not contraindicated in kidney transplant women but entails risks of maternal and fetal complications. Three main conditions can influence the outcome of pregnancy in transplant women: preconception counseling, maternal medical management, and correct use of drugs to prevent fetal toxicity. Preconception counseling is needed to prevent the risks of an unplanned untimely pregnancy. Pregnancy should be planned ≥2 years after transplantation. The candidate for pregnancy should have normal blood pressure, stable serum creatinine <1.5 mg/dL, and proteinuria <500 mg/24 h. Maternal medical management is critical for early detection and treatment of complications such as hypertension, preeclampsia, thrombotic microangiopathy, graft dysfunction, gestational diabetes, and infection. These adverse outcomes are strongly related to the degree of kidney dysfunction. A major issue is represented by the potential fetotoxicity of drugs. Moderate doses of glucocorticoids, azathioprine, and mTOR inhibitors are relatively safe. Calcineurin inhibitors (CNIs) are not associated with teratogenicity but may increase the risk of low birth weight. Rituximab and eculizumab should be used in pregnancy only if the benefits outweigh the risk for the fetus. Renin-angiotensin system inhibitors, mycophenolate, bortezomib, and cyclophosphamide can lead to fetal toxicity and should not be prescribed to pregnant women.

Fertility and Pregnancy in End Stage Kidney Failure Patients and after Renal Transplantation: An Update

Sexual life and fertility are compromised in end stage kidney disease both in men and in women. Successful renal transplantation may rapidly recover fertility in the vast majority of patients. Pregnancy modifies anatomical and functional aspects in the kidney and represents a risk of sensitization that may cause acute rejection. Independently from the risks for the graft, pregnancy in kidney transplant may cause preeclampsia, gestational diabetes, preterm delivery, and low birth weight. The nephrologist has a fundamental role in correct counseling, in a correct evaluation of the mother conditions, and in establishing a correct time lapse between transplantation and conception. Additionally, careful attention must be given to the antirejection therapy, avoiding drugs that could be dangerous to the newborn. Due to the possibility of medical complications during pregnancy, a correct follow-up should be exerted. Even if pregnancy in transplant is considered a high risk one, several data and studies document that in the majority of patients, the long-term follow-up and outcomes for the graft may be similar to that of non-pregnant women.

Increased risk of neonatal complications and infections in children of kidney-transplanted women: A nationwide controlled cohort study

Information related to short- and long-term risks of children born to kidney-transplanted women remains limited. With the aim of investigating the risk of neonatal complications, and the short- and long-term risk of infections in offspring of kidney-transplanted women, all children born to kidney-transplanted women in Denmark from 1964 to 2016 were identified in a nationwide retrospective matched cohort study. A total of 124 children of kidney-transplanted women were identified and matched on gender, birth year, and number of siblings at birth 1:10 with children born to nontransplanted women identified in the Danish general population. Prevalence of low birth weight (37.9%, risk ratio [RR] = 12.61; 95% confidence interval [CI], 8.5-18.5), premature birth (46.0%, RR = 11.32; 95% CI, 8.1-15.7) and malformations (11.3%, RR = 1.98; 95% CI, 1.2-3.4) was increased in children of kidney-transplanted women compared with controls. Similarly, prevalence of hospitalization due to infection was increased during the first year of life (21.0%, RR = 1.94; 95% CI, 1.3-2.8), from age 1 to 5 (34.2%, RR = 1.89; 95% CI, 1.4-2.5), and overall (41.9%, RR = 1.67; 95% CI, 1.3-2.1). The risk of infection was also higher in children of kidney-transplanted mothers born preterm or with low birth weight compared with similar controls. In conclusion, risk of neonatal complications, malformations, and both early and late infection were increased in children born to kidney-transplanted women.

In utero exposure to Azathioprine in autoimmune disease. Where do we stand?

Azathioprine (AZA), an oral immunosuppressant, is safe during pregnancy. Some reports suggested different impairments in the offspring of mothers with autoimmune diseases (AI) exposed in utero to AZA. These observations are available from retrospective studies or case reports. However, data with respect to the long-term safety in the antenatally exposed child are still lacking. The aim of this study is to summarize the current knowledge in this field and to focus on the need for a prospective study on this population. We performed a PubMed search using several search terms. The actual data show that although the risk of congenital anomalies in offspring, as well as the infertility risk, are similar to those found in general population, there is a higher incidence of prematurity, of lower weight at birth and an intra-uterine delay of development. There is also an increased risk of materno- fetal infections, especially cytomegalovirus infection. Some authors raise the interrogations about neurocognitive impairment. Even though the adverse outcomes might well be a consequence of maternal illness and disease activity, interest has been raised about a contribution of this drug. However, the interferences between the external agent (in utero exposure to AZA), with the host (child genetic susceptibility, immune system anomalies, emotional status), environment (public health, social context, availability of health care), economic, social, and behavioral conditions, cultural patterns, are complex and represent confounding factors. In conclusion, it is necessary to perform studies on the medium and long-term outcome of children born by mothers with autoimmune diseases, treated with AZA, in order to show the safety of AZA exposure. Only large-scale population studies with long-term follow-up will allow to formally conclude in this field. TAKE HOME MESSAGES.

Prevention of complications from use of conventional immunosuppressants: a critical review

Synthetic immunosuppressive drugs are largely used in immune-related renal diseases and in kidney transplantation. Most of these drugs have a low therapeutic index (the ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective), which means that the drug should be dosed carefully and the patient monitored frequently. In this review, we consider the categories of synthetic immunosuppressive agents more frequently and conventionally used in clinical nephrology: glucocorticoids, Aalkylating agents (cyclophosphamide, chlorambucil), purine synthesis inhibitors (azathioprine, mycophenolate salts) and calcineurin inhibitors (cyclosporine, tacrolimus). For each category the possible side effects will be reviewed, the general and specific measures to prevent or treat the adverse events will be suggested, and the more common mistakes that may increase the risk of toxicity will be described. However, the efficacy and safety of immunosuppressive agents depend not only on the pharmacologic characteristics of single drugs but can be influenced also by the clinical condition and genetic characteristics of the patient, by the typology and severity of the underlying disease and by the interaction with other concomitantly used drugs.

Tacrolimus treatment for infertility related to maternal-fetal immune interactions

Many approaches have been used to achieve successful pregnancies in patients with infertility, though existing treatments remain unsatisfactory in patients with infertility caused by abnormal maternal-fetal immunity. However, our understanding of the immunological aspects of infertility has steadily progressed, aided by recent research into organ transplantation and cancer. The results of these recent analyses have led to the development and evaluation of several candidate immunological treatments, but the use of immunological treatments remains a novel approach. The current paper presents the hypothesis that tacrolimus may have potential as a candidate agent for the treatment of maternal-fetal immunity-related infertility.

Pregnancy outcomes in women with kidney transplant: Metaanalysis and systematic review

BACKGROUND

Reproductive function in women with end stage renal disease generally improves after kidney transplant. However, pregnancy remains challenging due to the risk of adverse clinical outcomes.

METHODS

We searched PubMed/MEDLINE, Elsevier EMBASE, Scopus, BIOSIS Previews, ISI Science Citation Index Expanded, and the Cochrane Central Register of Controlled Trials from date of inception through August 2017 for studies reporting pregnancy with kidney transplant.

RESULTS

Of 1343 unique studies, 87 met inclusion criteria, representing 6712 pregnancies in 4174 kidney transplant recipients. Mean maternal age was 29.6 ± 2.4 years. The live-birth rate was 72.9% (95% CI, 70.0-75.6). The rate of other pregnancy outcomes was as follows: induced abortions (12.4%; 95% CI, 10.4-14.7), miscarriages (15.4%; 95% CI, 13.8-17.2), stillbirths (5.1%; 95% CI, 4.0-6.5), ectopic pregnancies (2.4%; 95% CI, 1.5-3.7), preeclampsia (21.5%; 95% CI, 18.5-24.9), gestational diabetes (5.7%; 95% CI, 3.7-8.9), pregnancy induced hypertension (24.1%; 95% CI, 18.1-31.5), cesarean section (62.6, 95% CI 57.6-67.3), and preterm delivery was 43.1% (95% CI, 38.7-47.6). Mean gestational age was 34.9 weeks, and mean birth weight was 2470 g. The 2-3-year interval following kidney transplant had higher neonatal mortality, and lower rates of live births as compared to > 3 year, and < 2-year interval. The rate of spontaneous abortion was higher in women with mean maternal age < 25 years and > 35 years as compared to women aged 25-34 years.

CONCLUSION

Although the outcome of live births is favorable, the risks of maternal and fetal complications are high in kidney transplant recipients and should be considered in patient counseling and clinical decision making.

Fetal Toxicity of Immunosuppressive Drugs in Pregnancy

Women affected by autoimmune diseases, organ transplantation, or neoplasia need to continue immunosuppressive treatment during pregnancy. In this setting, not only a careful planning of pregnancy, but also the choice of drugs is critical to preventing maternal complications and minimizing the fetal risks. Some immunosuppressive drugs are teratogenic and should be replaced even before the pregnancy, while other drugs need to be managed with caution to prevent fetal risks, including miscarriage, intrauterine growth restriction, prematurity, and low birth weight. In particular, the increasing use of biologic agents raises the question of their compatibility with reproduction. In this review we present data on the indication and safety in pregnancy of the most frequently used immunosuppressive drugs.