Impact of Pregnancy on the Function of Transplanted Kidneys

Counselling on Conceiving: Attitudes and Factors Influencing Advice of Professionals in Transplantation

Pregnancy after kidney transplantation (KT) conveys risks of adverse pregnancy outcomes (APO). Little is known about performance of pre-pregnancy counselling after KT. This study investigated perceptions of risk, attitudes towards pregnancy and factors influencing advice given at pre-pregnancy counselling after KT. A web-based vignette survey was conducted among nephrologists and gynaecologists between March 2020 and March 2021, consisting of five vignettes containing known risk factors for APO and general questions on pre-pregnancy counselling after KT. Per vignette, attitudes towards pregnancy and estimation of outcomes were examined. In total 52 nephrologists and 25 gynaecologists participated, 56% from university hospitals. One third had no experience with pregnancy after KT. All gave positive pregnancy advice in the vignette with ideal circumstances (V1), versus 83% in V2 (proteinuria), 81% in V3 (hypertension), 71% in V4 (eGFR 40 ml/min/1.73 m²). Only 2% was positive in V5 (worst-case scenario). Chance of preeclampsia was underestimated by 89% in V1. 63% and 98% overestimated risk for graft loss in V4 and V5. Professionals often incorrectly estimated risk of APO after KT. As experience with pregnancy after KT was limited among professionals, patients should be referred to specialised centres for multidisciplinary pre-pregnancy counselling to build experience and increase consistency in given advice.

Interconception Care for Primary Care Providers: Consensus Recommendations on Preconception and Postpartum Management of Reproductive-Age Patients With Medical Comorbidities

Severe maternal morbidity and mortality continue to increase in the United States, largely owing to chronic and newly diagnosed medical comorbidities. Interconception care, or care and management of medical conditions between pregnancies, can improve chronic disease control before, during, and after pregnancy. It is a crucial and time-sensitive intervention that can decrease maternal morbidity and mortality and improve overall health. Despite these potential benefits, interconception care has not been well implemented by the primary care community. Furthermore, there is a lack of guidelines for optimizing preconception chronic disease, risk stratifying postpartum chronic diseases, and recommending general collaborative management principles for reproductive-age patients in the period between pregnancies. As a result, many primary care providers, especially those without obstetric training, are unclear about their specific role in interconception care and may be unsure of effective methods for collaborating with obstetric care providers. In particular, internal medicine physicians, the largest group of primary care physicians, may lack sufficient clinical exposure to medical conditions in the obstetric population during their residency training and may feel uncomfortable in caring for these patients in their subsequent practice.

The objective of this article is to review concepts around interconception care, focusing specifically on preconception care for patients with chronic medical conditions (eg, chronic hypertension, chronic diabetes mellitus, chronic kidney disease, venous thromboembolism, and obesity) and postpartum care for those with medically complicated pregnancies (eg, hypertensive disorders of pregnancy, gestational diabetes mellitus, excessive gestational weight gain, peripartum cardiomyopathy, and peripartum mood disorders). We also provide a pragmatic checklist for preconception and postpartum management.

Obstetric and long-term graft outcomes in pregnant kidney transplant recipients: A single-center experience

BACKGROUND

Kidney transplantation (KT) is the best option for many women with end-stage renal disease desiring pregnancy. The aim of this study was to investigate obstetric and graft outcomes among KT recipient women in our center.

METHODS

Maternal and fetal data were assessed in 29 pregnancies of 18 female KT recipients. Each patient was matched with two controls without pregnancy history for factors known to affect graft function. According to pre-pregnancy levels, serum creatinine and eGFR slope in the gestational and postpartum periods were calculated as percentages.

RESULTS

The main maternal and fetal complications were preeclampsia (38%) and preterm births (38%), respectively. Pregnancy (odds ratio [OR]: 5.09; p = .02), proteinuria in the third trimester (OR: 5.52; p = .02), proteinuria in postpartum third months (OR: 7.4; p = .008) and stable creatinine levels in the first 6 months of pregnancy (OR: 11.25 p = .03) were associated with graft dysfunction. Postpartum first year eGFR decline (-16.8% vs. -6.7%; p = .04) and second-year eGFR decline (-18.5% vs. -8.3%; p = .04) were significantly higher in the pregnancy group than those matched controls.

CONCLUSION

Pregnancy after KT is associated with high rates of maternal and fetal complications. The sustained decline of eGFR may suggest an increased risk of graft loss compared to recipients with similar clinical characteristics.

Long-term Graft Survival and Graft Function Following Pregnancy in Kidney Transplant Recipients: A Systematic Review and Meta-analysis

BACKGROUND

The incidence of pregnancy in kidney transplantation (KT) recipients is increasing. Studies report that the incidence of graft loss (GL) during pregnancy is low, but less data are available on long-term effects of pregnancy on the graft.

METHODS

Therefore, we performed a meta-analysis and systematic review on GL and graft function, measured by serum creatinine (SCr), after pregnancy in KT recipients, stratified in years postpartum. Furthermore, we included studies of nulliparous KT recipients.

RESULTS

Our search yielded 38 studies on GL and 18 studies on SCr. The pooled incidence of GL was 9.4% within 2 years after pregnancy, 9.2% within 2-5 years, 22.3% within 5-10 years, and 38.5% >10 years postpartum. In addition, our data show that, in case of graft survival, SCr remains stable over the years. Only within 2 years postpartum, Δ SCr was marginally higher (0.18 mg/dL, 95%CI [0.05-0.32], P = 0.01). Furthermore, no differences in GL were observed in 10 studies comparing GL after pregnancy with nulliparous controls. Systematic review of the literature showed that mainly prepregnancy proteinuria, hypertension, and high SCr are risk factors for GL.

CONCLUSIONS

Overall, these data show that pregnancy after KT has no effect on long-term graft survival and only a possible effect on graft function within 2 years postpartum. This might be due to publication bias. No significant differences were observed between pre- and postpartum SCr at longer follow-up intervals.

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.

Pregnancy in Renal Transplant Recipients and Donors

Women with renal transplants have restoration of fertility with improved kidney function; however, pregnancy rates in renal transplant recipients appear to be lower than the general population, which might be influenced by patient choice. Women with renal transplants need to evaluate potential neonatal outcomes, graft outcomes, and risks to their own health to make informed decisions about conception. Pregnancy should be carefully planned in renal transplant recipients to reduce risk for graft loss, optimize pregnancy outcomes, and ensure immunosuppression regimes are nonteratogenic. Neonatal outcomes remain significantly worse for women with renal transplants than healthy controls, particularly for those with reduced graft function, hence prepregnancy, antenatal, and postpartum care of women with renal transplants should be guided by a multidisciplinary team of nephrologists and specialist obstetricians.

Pregnancy across the spectrum of chronic kidney disease

Management of the pregnant woman with chronic kidney disease is difficult for both nephrologists and obstetricians. Prepregnancy counselling with respect to risk stratification, optimization of maternal health prior to pregnancy, as well as management of the many potential pregnancy-associated complications in this complex patient population remains challenging due to the paucity of large, well-designed clinical studies. Furthermore, the heterogeneity of disease and the relative infrequency of pregnancy, particularly in more advanced stages of chronic kidney disease, leaves many clinicians feeling ill prepared to manage these pregnancies. As such, counselling is imprecise and management varies substantially across centers. All pregnancies in women with chronic kidney disease can benefit from a collaborative multidisciplinary approach with a team that consists of nephrologists experienced in the management of kidney disease in pregnancy, maternal-fetal medicine specialists, high-risk pregnancy nursing staff, dieticians, and pharmacists. Further access to skilled neonatologists and neonatal intensive care unit support is essential given the risks for preterm delivery in this patient population. The goal of this paper is to highlight some of the data that currently exist in the literature, provide management strategies for the practicing nephrologist at all stages of chronic kidney disease, and explore some of the knowledge gaps where future multinational collaborative research efforts should concentrate to improve pregnancy outcomes in women with kidney disease across the globe.

Pre-pregnancy counselling for women with chronic kidney disease: a retrospective analysis of nine years' experience

Background

Women with chronic kidney disease have an increased risk of maternal and fetal complications in pregnancy. Pre-pregnancy counselling is recommended but the format of the counselling process and the experience of the patient have never been assessed. This study examines the experience of women with chronic kidney disease attending pre-pregnancy counselling and evaluates their pregnancy outcomes.

Methods

This is a cross-sectional assessment of 179 women with chronic kidney disease attending a pre-pregnancy counselling clinic (2003–2011) with retrospective evaluation of aetiology, comorbidity, treatment and adverse pregnancy outcome compared with 277 hospital controls. It includes an analysis of descriptive data and free text content from 72 questionnaire responders.

Results

65/72 (90%) of women found the clinic informative. 66 women (92%) felt that the consultation had helped them decide about pursuing pregnancy. 12 women (17%) found the multidisciplinary process intimidating. Free text comments supported the positive nature of the counselling experience, but also highlighted issues of access and emotional impact. Adverse pregnancy outcome rates were significantly higher in women with chronic kidney disease: 7/35 (20%) had pre-eclampsia (p < 0.001), 8/35 (23%) infants were small for gestational age (p < 0.001), 11/35 (31%) had preterm deliveries (<37 weeks) (p < 0.001) and 5/35 (14%) had a pregnancy loss compared with 4%, 10%, 8% and 3% of controls respectively.

Conclusions

Women with a diverse range of renal disease severity and complexity attend pre-pregnancy counselling. Factors affecting pregnancy include hypertension, proteinuria and teratogenic medication. It is important to be able to inform women of the risks to them and their babies before pregnancy in order to facilitate informed-decision making. Most women with chronic kidney disease attending a pre-pregnancy counselling clinic report a positive experience.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0024-6) contains supplementary material, which is available to authorized users.

Preconception counseling, fertility, and pregnancy complications after abdominal organ transplantation: a survey and cohort study of 532 recipients

BACKGROUND

Pregnancy after solid organ transplant is a significant priority for transplant recipients but how patients report being counseled is unknown.

METHODS

We performed a single-center retrospective cohort study and telephone survey of female patients ages 18-49 at the time of kidney, pancreas, or liver transplant from 2000 to 2012 (n = 532). Data on pregnancy counseling, fertility, and maternal, fetal- and transplant-specific outcomes were collected. Multivariate Cox models assessed the impact of pregnancy on graft-specific outcomes.

RESULTS

The survey response rate was 29% (n = 152). One-third (n = 51) of women were actively counseled against pregnancy by one or more providers. A total of 17 pregnancies occurred among nine patients (5.9%), with 47% live births, 47% early embryonic demises, 5.9% stillbirths. Of live births, 50% were premature. Gestational complications, including diabetes, hypertension, and preeclampsia were present in 88% of mothers. Pregnancy after transplant was associated with higher rates of acute rejection than nulliparous transplant recipients (33% vs. 5.6%, p = 0.07) but did not significantly affect graft survival (HR = 1.00, 95% CI 0.99-1.01), after stratifying by organ and adjusting for clinical factors.

CONCLUSION

This study suggests that transplant patients are being counseled against pregnancy despite acceptable risks of complications and no specific effects on long-term graft function.

Interpreting tacrolimus concentrations during pregnancy and postpartum

Pregnancy after solid organ transplantation, although considered high risk for maternal, fetal, and neonatal complications, has been quite successful. Tacrolimus pharmacokinetic changes during pregnancy make interpretation of whole blood trough concentrations particularly challenging. There are multiple factors that can increase the fraction of unbound tacrolimus, including but not limited to low albumin concentration and low red blood cell count. The clinical titration of dosage to maintain whole blood tacrolimus trough concentrations in the usual therapeutic range can lead to elevated unbound concentrations and possibly toxicity in pregnant women with anemia and hypoalbuminemia. Measurement of plasma or unbound tacrolimus concentrations for pregnant women might better reflect the active form of the drug, although these are technically challenging and often unavailable in usual clinical practice. Tacrolimus crosses the placenta with in utero exposure being approximately 71% of maternal blood concentrations. The lower fetal blood concentrations are likely due to active efflux transport of tacrolimus from the fetus toward the mother by placental P-glycoprotein. To date, tacrolimus has not been linked to congenital malformations but can cause reversible nephrotoxicity and hyperkalemia in the newborn. In contrast, very small amounts of tacrolimus are excreted in the breast milk and are unlikely to elicit adverse effects in the nursing infant.

Administration of calcitonin promotes blastocyst implantation in mice by up-regulating integrin β3 expression in endometrial epithelial cells

STUDY QUESTION

Does exogenous calcitonin improve the efficiency of implantation in mice by increasing uterine receptivity?

SUMMARY ANSWER

The administration of calcitonin could improve the efficiency of implantation by increasing the expression of several receptivity-related genes in endometrial epithelial cells (EECs).

WHAT IS KNOWN ALREADY

Calcitonin is one of the biomarkers of uterine receptivity, which is transiently produced in the uterine epithelia during the period of implantation both in humans and mouse.

STUDY DESIGN, SIZE, DURATION

Hormone-replaced mice were used for in vivo experiments. To evaluate the effect of calcitonin on uterine receptivity, the expression of endometrial genes was analyzed 36 h after i.p. injection of 0.5 IU calcitonin in a treatment group versus saline in the control. To evaluate the effect of calcitonin on implantation efficiency in vivo, two groups received 0.5 IU or 2 IU calcitonin (i.p.) 24 h before embryo transfer, and a control group received saline (i.p.) (n = 18 mice per group). Implantation sites were counted 7 days after embryo transfer. The RL95-2 human endometrial carcinoma cell line was used to study the mechanisms underlying the effect of calcitonin on gene expression in the endometria. Using an in vitro model of endometrium-trophoblast interaction, established with RL95-2 cells and JAR (human choriocarcinoma cell line) trophoblast, endometrial receptivity was evaluated by comparing attachment and outgrowth of JAR spheroids in control and treatment groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Uterine receptivity in ovariectomized mice was induced by injection of estradiol and progesterone. Expression of eight genes in murine endometrium and RL95-2 cells was analyzed by real-time RT-PCR, western blot, immunohistochemical analysis, flow cytometry and enzyme-linked immunosorbent assay. We tested the effects of a protein kinase C inhibitor, matrigel and an antibody against integrin αvβ3 using RL95-2 cells and performed attachment and outgrowth assays using the in vitro model of endometrium-trophoblast interaction. Implantation efficiency was evaluated by counting the implantation sites after embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

Calcitonin up-regulated αvβ3 in RL95 cells, which in turn resulted in increased levels of the leukemia inhibitory factor (LIF) and heparin binding-epidermal growth factor (HB-EGF) mRNA (both P < 0.01 versus control) and protein (both P < 0.05 versus control). The attachment and expansion of JAR spheroids was promoted by pretreatment of EECs with calcitonin (P < 0.05 versus control) together with significantly increased expression of αvβ3, LIF and HB-EGF. Moreover, the injection of calcitonin in the preimplantation phase increased the total number of implantation sites in treatment groups (55 in control versus 78 and 85 in 0.5 and 2 IU groups, respectively). Compared with the control group (3.11 ± 2.14), the average number of implantation sites in the 2 IU calcitonin treatment group increased (4.72 ± 1.87, P = 0.022).

LIMITATIONS, REASONS FOR CAUTION

Experiments were performed in mice and human cell lines but not in primary cultures of human endometrial cells.

WIDER IMPLICATIONS OF THE FINDINGS

The findings presented here have important implications, in that calcitonin administration (currently used for treatment of hypercalcemia or osteoporosis) may have clinical benefits in assisted reproduction programs, by facilitating endometrial receptivity and embryo implantation. However, further studies are required to confirm these findings.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by National Science Foundation of China (No. 81170619). There are no financial or commercial conflicts in this study.

Pregnancy outcomes in kidney transplant recipients: a systematic review and meta-analysis

Approximately 50,000 women of reproductive age in the United States are currently living after kidney transplantation (KT), and another 2800 undergo KT each year. Although KT improves reproductive function in women with ESRD, studies of post-KT pregnancies are limited to a few voluntary registry analyses and numerous single-center reports. To obtain more generalizable inferences, we performed a systematic review and meta-analysis of articles published between 2000 and 2010 that reported pregnancy-related outcomes among KT recipients. Of 1343 unique studies, 50 met inclusion criteria, representing 4706 pregnancies in 3570 KT recipients. The overall post-KT live birth rate of 73.5% (95%CI 72.1-74.9) was higher than the general US population (66.7%); similarly, the overall post-KT miscarriage rate of 14.0% (95%CI 12.9-15.1) was lower (17.1%). However, complications of preeclampsia (27.0%, 95%CI 25.2-28.9), gestational diabetes (8.0%, 95%CI 6.7-9.4), Cesarean section (56.9%, 95%CI 54.9-58.9) and preterm delivery (45.6%, 95%CI 43.7-47.5) were higher than the general US population (3.8%, 3.9%, 31.9% and 12.5%, respectively). Pregnancy outcomes were more favorable in studies with lower mean maternal ages; obstetrical complications were higher in studies with shorter mean interval between KT and pregnancy. Although post-KT pregnancy is feasible, complications are relatively high and should be considered in patient counseling and clinical decision making.

Pregnancy outcome in women with chronic kidney disease: a prospective cohort study

OBJECTIVE

To evaluate pregnancy outcome in women with chronic kidney disease (CKD) or proteinuria in early pregnancy with concomitant risk for preeclampsia (PE).

METHODS

Thirty-six women with CKD (Cr > 100 μmol/L at booking or Cr > 125 μmol/L prepregnancy or proteinuria ≥ 500 mg/24 hours at booking) and 30 women with proteinuria (≥2+) and known clinical risk for PE were enrolled at 14(+0) to 21(+6) weeks. Pregnancy outcomes were assessed.

RESULTS

Women with mild CKD (prepregnancy Cr < 125 µmol/Cr > 100 µmol at booking; n = 22) had high rates of preeclampsia (40%), preterm delivery (<37 weeks' gestation; 54%), SGA infants (<10th adjusted centile; 64%)and perinatal death (5%). Women with moderate/severe CKD (prepregnancy creatinine > 125 µmol; n = 14) had poor perinatal outcomes: preterm delivery (86%) and perinatal death (14%). Women with proteinuria (≥2+) and concomitant risk of PE also had high rates of pre-eclampsia (60%), preterm delivery (40%), and SGA infants (27%).

CONCLUSIONS

Pregnancy complications for women with CKD remain high. Women with risk factors for PE with proteinuria (≥2+) at booking are also high-risk.

Obstetric considerations in the management of pregnancy in kidney transplant recipients

Kidney transplant improves reproductive function; planning for pregnancy is crucial. Prenatal management must address potential fetal complications: preterm delivery, intrauterine growth restriction, low birth weight; as well as maternal: hypertension, preeclampsia, gestational diabetes, acute rejection or graft loss. The latter depends upon timing after transplant, prepregnancy kidney function, and continuation of immunosuppressive agents at appropriate levels. Graft function is not adversely affected if preconception kidney function was normal. Acute rejection, 9%-14%, must be immediately addressed, with kidney biopsy if necessary. Blood pressure should be meticulously managed; serious morbidity results from poor control. Blood pressures >130/80 mmHg require acceptable antihypertensives: beta-blockers, alpha-methyldopa, hydralazine, and calcium channel blockers. Preeclampsia requires seizure prophylaxis with magnesium sulfate, with expeditious delivery. Screening for urinary tract infections with aggressive treatment and for opportunistic infections that may affect the fetus is essential. Surveillance for fetal anomalies, growth, and antenatal testing is important. Steroids for fetal lung maturity are indicated for preterm delivery. Vaginal birth is preferred, reserving cesarean for obstetrical indications, with pain management similar to normal laboring patients. Surveillance for infection postpartum is warranted. Conflicting information exists regarding safety of breastfeeding with immunosuppressive drugs; immunosuppressive medication must be adjusted to prepregnancy levels and contraception counseling addressed.

Cholestasis in pregnancy associated with ciclosporin therapy in renal transplant recipients

Obstetric cholestasis (OC) presents with pruritus in the second half of pregnancy and is associated with increased risk of foetal distress, intra-uterine death and premature delivery. From a tertiary referral, renal-obstetric clinic, we report the occurrence of OC in 5/23 pregnancies of women with renal transplants maintained on ciclosporin treatment (European incidence 0.1-1.5% of pregnancies). All required premature delivery for foetal reasons at 33-37/40 (median 34/40). Ciclosporin, at therapeutic concentrations, inhibits bile salt excretion pump (BSEP) function in rats and humans. We propose that OC developed in our patients because the mild inhibition of the canalicular pumps by ciclosporin was only revealed in pregnancy when increases in progesterone metabolites overwhelmed pump function. We suggest that all pregnant women receiving ciclosporin should be closely monitored from the second trimester for the development of OC. If detected, enhanced foetal and maternal monitoring to optimize time of delivery and pregnancy outcome is required.

Immunosuppression and immune monitoring after renal transplantation

Monitoring of immunosuppression therapy in renal transplant recipients is essential for good patient and graft survival. Monitoring includes frequent laboratory assays of serum immunosuppression levels, patient visits to assess and treat side effects, and vigilance for medication interactions. We review the various immunosuppression medications commonly used in renal transplantation, including usual dosing and side effects. Monitoring assays are discussed, as well as the frequency of monitoring and patient visits. Finally, we discuss several common clinical scenarios that often require adjustment of immunosuppression medications or regimens.