Impact of Pregnancy on the Outcome of Kidney Transplantation

Effect of Pregnancy on eGFR After Kidney Transplantation: A National Cohort Study

BACKGROUND

The effect of pregnancy on the course of estimated glomerular filtration rate (eGFR) is unknown in kidney transplant recipients (KTRs).

METHODS

We conducted a nationwide multicenter cohort study in KTRs with pregnancy (>20 wk) after kidney transplantation (KT). Annual eGFRs after KT until death or graft loss and additional eGFRs before each pregnancy were collected according to protocol. Changes in eGFR slope before and after each pregnancy were analyzed by generalized estimating equations multilevel analysis adjusted for transplant vintage.

RESULTS

We included 3194 eGFR measurements before and after pregnancy in 109 (55%) KTRs with 1, 78 (40%) with 2, and 10 (5%) with 3 pregnancies after KT. Median follow-up after first delivery post-KT was 14 y (interquartile range, 18 y). Adjusted mean eGFR prepregnancy was 59 mL/min/1.73 m2 (SEM [standard error of the mean] 1.72; 95% confidence interval [CI], 56-63), after the first pregnancy 56 mL/min/1.73 m2 (SEM 1.70; 95% CI, 53-60), after the second pregnancy 56 mL/min/1.73 m2 (SEM 2.19; 95% CI, 51-60), and after the third pregnancy 55 mL/min/1.73 m2 (SEM 8.63; 95% CI, 38-72). Overall eGFR slope after the first, second, and third pregnancies was not significantly worse than prepregnancy (P = 0.28). However, adjusted mean eGFR after the first pregnancy was 2.8 mL/min/1.73 m2 (P = 0.08) lower than prepregnancy.

CONCLUSIONS

The first pregnancy has a small, but insignificant, effect on eGFR slope in KTRs. Midterm hyperfiltration, a marker for renal reserve capacity, was associated with better eGFR and death-censored graft survival. In this KTR cohort with long-term follow-up, no significant effect of pregnancy on kidney function was detected.

Graft function and pregnancy outcomes after kidney transplantation

Background

After kidney transplantation, pregnancy and graft function may have a reciprocal interaction. We evaluated the influence of graft function on the course of pregnancy and vice versa.

Methods

We performed a retrospective observational study of 92 pregnancies beyond the first trimester in 67 women after renal transplantation from 1972 to 2019. Pre-pregnancy eGFR was correlated with outcome parameters; graft function was evaluated by Kaplan Meier analysis. The course of graft function in 28 women who became pregnant after kidney transplantation with an eGFR of < 50 mL/min/1.73m² was compared to a control group of 79 non-pregnant women after kidney transplantation during a comparable time period and with a matched basal graft function.

Results

Live births were 90.5% (fetal death n = 9). Maternal complications of pregnancy were preeclampsia 24% (graft loss 1, fetal death 3), graft rejection 5.4% (graft loss 1), hemolytic uremic syndrome 2% (graft loss 1, fetal death 1), maternal hemorrhage 2% (fetal death 1), urinary obstruction 10%, and cesarian section. (76%). Fetal complications were low gestational age (34.44 ± 5.02 weeks) and low birth weight (2322.26 ± 781.98 g). Mean pre-pregnancy eGFR was 59.39 ± 17.62 mL/min/1.73m² (15% of cases < 40 mL/min/1.73m²). Pre-pregnancy eGFR correlated with gestation week at delivery (R = 0.393, p = 0.01) and with percent eGFR decline during pregnancy (R = 0.243, p = 0.04). Pregnancy-related eGFR decline was inversely correlated with the time from end of pregnancy to chronic graft failure or maternal death (R = -0.47, p = 0.001). Kaplan Meier curves comparing women with pre-pregnancy eGFR of ≥ 50 to < 50 mL/min showed a significantly longer post-pregnancy graft survival in the higher eGFR group (p = 0.04). Women after kidney transplantation who became pregnant with a low eGFR of > 25 to < 50 mL/min/1.73m² had a marked decline of renal function compared to a matched non-pregnant control group (eGFR decline in percent of basal eGFR 19.34 ± 22.10%, n = 28, versus 2.61 ± 10.95%, n = 79, p < 0.0001).

Conclusions

After renal transplantation, pre-pregnancy graft function has a key role for pregnancy outcomes and graft function. In women with a low pre-pregnancy eGFR, pregnancy per se has a deleterious influence on graft function.

Trial registration

Since this was a retrospective observational case series and written consent of the patients was obtained for publication, according to our ethics’ board the analysis was exempt from IRB approval. Clinical Trial Registration was not done. The study protocol was approved by the Ethics Committee of Hannover Medical School, Chairman Prof. Dr. H. D. Troeger, Hannover, December 12, 2015 (IRB No. 2995–2015).

Pregnancy After Kidney Transplantation

BACKGROUND

Pregnancy after kidney transplantation is an uncommon event. In addition to the risk to the child and the mother, pregnancy has a certain risk for the transplanted kidney.

METHODS

We made a retrospective analysis of pregnancy and kidney function over a 49-year period in women with transplanted kidneys monitored at the National Transplant Centre, University Medical Centre Ljubljana, Ljubljana, Slovenia.

RESULTS

We analyzed 22 pregnancies in 18 women (26-39 years old) 78 ± 37 months after transplantation. Serum creatinine before conception was 92 ± 26 μmol/L; 3 years after delivery, it was 117 ± 67 μmol/L. There were no rejections during pregnancy. Three rejections occurred in the first 9 months after delivery. The median duration of pregnancies was 37 weeks. Preeclampsia occurred in 4 women and severe eclampsia occurred in 2 women. In 19 cases, delivery was by caesarean section. One child was born with trisomy of chromosome 21 and 3 children were born with minor congenital anomalies.

CONCLUSIONS

Renal function and proteinuria did not deteriorate 3 years after pregnancy, even after 2 pregnancies. Rejections in the early post-pregnancy period were common. Preeclampsia was more frequent than in the average population. The incidence of major congenital anomalies was comparable to that seen in pregnant women without immunosuppression.

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 after renal transplantation: a retrospective study at the military hospital of Tunis from 1992 to 2011

Introduction

Our study objective was to analyze the optimum conditions for pregnancy in kidney transplanted women. For that, we conducted a retrospective study was from 1992 to April 2011 about 17 pregnancies in 12 kidney transplanted patients followed in the Department of Obstetrics and Gynecology and Organ Transplant Unit of the Military Hospital of Tunis.

Methods

We studied nephrological parameters and obstetric pathologies encountered during pregnancy and the potential impact of pregnancy on graft. Our main outcome measures were: time between renal transplantation and conception, birth of a living child, renal graft defect.

Results

The mean age at the time of renal transplantation was 30.11 years. The average age at the time of conception is 34.23 years. The average time between renal transplantation and the occurrence of pregnancy was 46.94 months. More than 40% of pregnancies were not planned. Of the 17 pregnancies, 12 have advanced beyond the first trimester with 91.6% resulting in the birth of a living child. Toxemia was found in 60% of cases, low birth weight in 50%, preterm in 30% and intrauterine growth retardation in 20% of cases. Cesarean section was indicated in all cases. Graft survival was 90% with a mean of 6 years after delivery.

Conclusion

Pregnancy in kidney transplanted patients is a high-risk pregnancy, but pregnancy does not appear to affect graft function through certain conditions.

Timing of Pregnancy After Kidney Transplantation and Risk of Allograft Failure

The optimal timing of pregnancy after kidney transplantation remains uncertain. We determined the risk of allograft failure among women who became pregnant within the first 3 posttransplant years. Among 21 814 women aged 15-45 years who received a first kidney-only transplant between 1990 and 2010 captured in the United States Renal Data System, n = 729 pregnancies were identified using Medicare claims. The probability of allograft failure from any cause including death (ACGL) at 1, 3, and 5 years after pregnancy was 9.6%, 25.9%, and 36.6%. In multivariate analyses, pregnancy in the first posttransplant year was associated with an increased risk of ACGL (hazard ratio [HR]: 1.18; 95% confidence interval [CI] 1.00, 1.40) and death censored graft loss (DCGL) (HR:1.25; 95% CI 1.04, 1.50), while pregnancy in the second posttransplant year was associated with an increased risk of DCGL (HR: 1.26; 95% CI 1.06, 1.50). Pregnancy in the third posttransplant year was not associated with an increased risk of ACGL or DCGL. These findings demonstrate a higher incidence of allograft failure after pregnancy than previously reported and that the increased risk of allograft failure extends to pregnancies in the second posttransplant year.

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.

[Impact of end-stage renal disease and kidney transplantation on the reproductive system]

Chronic renal failure leads to many metabolic disorders affecting reproductive function. For men, hypergonadotropic hypogonadism, hyperprolactinemia, spermatic alterations, decreased libido and erectile dysfunction are described. Kidney transplantation improves sperm parameters and hormonal function within 2 years. But sperm alterations may persist with the use of immunosuppressive drugs. In women, hypothalamic-pituitary-ovarian axis dysfunction due to chronic renal failure results in menstrual irregularities, anovulation and infertility. After kidney transplantation, regular menstruations usually start 1 to 12 months after transplantation. Fertility can be restored but luteal insufficiency can persist. Moreover, 4 to 20% of women with renal transplantation suffer from premature ovarian failure syndrome. In some cases, assisted reproductive technologies can be required and imply risks of ovarian hyperstimulation syndrome and must be performed with caution. Pregnancy risks for mother, fetus and transplant are added to assisted reproductive technologies ones. Only 7 authors have described assisted reproductive technologies for patients with kidney transplantation. No cases of haemodialysis patients have been described yet. So, assisted reproductive technologies management requires a multidisciplinary approach with obstetrics, nephrology and reproductive medicine teams' agreement.

Twin pregnancy after kidney transplantation: what's on? A case report and review of literature

OBJECTIVE

To describe the maternal and neonatal outcome of a twin pregnancy in a renal transplant recipient patient and reviewe the current literature on this theme.

METHODS

A case of 27 years old woman with a twin pregnancy arisen spontaneously in a renal transplant recipient from living donor characterized by an episode of slight anemia, mild hypertension, and a subsequent optimal maternal/neonatal outcome. During admission, the patient was treated with iron therapy, nifedipine, and methyldopa due to anemia and hypertension episodes. Strict monitoring of patient's blood and urinary parameters, ultrasound fetues evaluation, and fetal lung maturity induction was performed.

RESULTS

Both anemia and hypertension were controlled through pharmacological intervention. During the second admission, the serum creatinine was 185 μmol/L and urine examination showed a proteinuria of 0.3 g/L. Ultrasound evaluation showed fetal wellness for both twin. Patient underwent caesarean section and gave birth to two healthy babies.

CONCLUSIONS

It is necessary to define more strict criteria for the management of women with twin pregnancy and a history of renal transplantation to ensure the better maternal and neonatal outcome.

Pregnancy after renal transplantation: a review of registry and single-center practices and outcomes

Registries from North America, Australia and Europe are rich sources of clinical data on pregnancy after kidney transplantation. Single-center reports of pregnancy outcomes are limited by small sample sizes but not by the potential reporting bias that can impact registry data. Despite the differences in data pools, the obstetric and graft outcomes reported by single centers and registries have been similar. The majority of pregnancies are successful in renal transplant patients, but the risk of complications like pre-eclampsia, low birth weight and premature birth is high. Pregnancy has no significant impact on graft function or survival when baseline function is normal.

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 after renal transplantation: an evaluation of the graft function

OBJECTIVES

To evaluate pregnancy outcomes and graft function in renal transplant recipients.

STUDY DESIGN

Thirty-four pregnancies in 31 patients were evaluated. Graft dysfunction was defined as an increase of 0.3mg/dL (215 μmol/L) or more in serum creatinine (SCr) during pregnancy. Twenty-eight patients were also evaluated at one, six and twelve months after delivery to analyze the evolution of the graft function.

RESULTS

Fifteen patients experienced graft dysfunction during pregnancy, 10 related to preeclampsia, two related to rejection, one related to allograft obstruction and one related to urinary tract infection. One patient did not have an identified cause. In one patient, graft rejection ended in graft loss. The mean SCr level in the first trimester was 0.9 mg/dL (range: 0.5-2.1) among women who did not have graft dysfunction and 1.1mg/dL (range: 0.5-1.9) among patients who had graft dysfunction (P=0.66). The mean SCr level one year after delivery was 1.18 mg/dL in the first group and 1.21 mg/dL in the second group (P=0.74). There was no difference in SCr level from the first trimester of pregnancy to one year after delivery in both groups evaluated (P=0.35 and P=0.13).

CONCLUSIONS

Although graft dysfunction may occur during pregnancy, it seems to be temporary in the majority of the cases. It is important to emphasize that rejection is still a cause of graft loss during pregnancy.

Measurements of serum pituitary-gonadal hormones and investigation of sexual and reproductive functions in kidney transplant recipients

Objective. To investigate changes in serum pituitary-gonadal hormones and restoration of sexual and reproductive functions after successful kidney transplantation. Patients and Methods. Serum pituitary-gonadal hormones before and after kidney transplantation were measured in 78 patients with end-stage renal disease (ESRD) and in 30 healthy adults. Pre- and postoperative semen specimens of 46 male recipients and 15 male controls were collected and compared. Additional 100 married kidney transplant recipients without children were followed up for 3 years to observe their sexual function and fertility. Results. Serum PRL, LH, and T or E₂ levels gradually restored to the normal ranges in all kidney transplant recipients, and sperm density, motility, viability, and morphology significantly improved in the male recipients 4 months after successful kidney transplantation (P < .05). Thirty-three male recipients (55.93%) reobtained normal erectile function, and 49 kidney transplant recipients (61.25%) had children within the 3-year follow-up period. Conclusion. Successful kidney transplantation could effectively improve pituitary-gonadal hormone disturbance and sexual and reproductive dysfunctions of ESRD patients.

Pregnancy and maternal outcomes among kidney transplant recipients

Fertility rates, pregnancy, and maternal outcomes are not well described among women with a functioning kidney transplant. Using data from the Australian and New Zealand Dialysis and Transplant Registry, we analyzed 40 yr of pregnancy-related outcomes for transplant recipients. This analysis included 444 live births reported from 577 pregnancies; the absolute but not relative fertility rate fell during these four decades. Of pregnancies achieved, 97% were beyond the first year after transplantation. The mean age at the time of pregnancy was 29 +/- 5 yr. Compared with previous decades, the mean age during the last decade increased significantly to 32 yr (P < 0.001). The proportion of live births doubled during the last decade, whereas surgical terminations declined (P < 0.001). The fertility rate (or live-birth rate) for this cohort of women was 0.19 (95% confidence interval 0.17 to 0.21) relative to the Australian background population. We also matched 120 parous with 120 nulliparous women by year of transplantation, duration of transplant, age at transplantation +/-5 yr, and predelivery creatinine for parous women or serum creatinine for nulliparous women; a first live birth was not associated with a poorer 20-yr graft or patient survival. Maternal complications included preeclampsia in 27% and gestational diabetes in 1%. Taken together, these data confirm that a live birth in women with a functioning graft does not have an adverse impact on graft and patient survival.