Comparison of pregnancy outcomes in Dutch kidney recipients with and without calcineurin inhibitor exposure: a retrospective study

Preeclampsia after Kidney Transplantation: Rates and Association with Graft Survival and Function

BACKGROUND

Transplanted women have high rates of preeclampsia. However, determinants of preeclampsia and association with graft survival and function remain uncertain. We aimed to determine rates of preeclampsia and its association with kidney transplant survival and function.

METHODS

This was a retrospective cohort study analyzing postkidney transplantation pregnancies (≥20 weeks gestation) from the Australia and New Zealand Dialysis and Transplant Registry (2000-2021). Graft survival was assessed in three models accounting for repeated pregnancies and episodes of preeclampsia.

RESULTS

Preeclampsia status was captured in 357 of 390 pregnancies and occurred in 133 pregnancies (37%). The percentage of pregnancies reported to have preeclampsia rose from 27% in 2000-2004 to 48% from 2018 to 2021. Reported prior exposure to calcineurin inhibitors was high overall and higher in women who had preeclampsia (97% versus 88%, P = 0.005). Seventy-two (27%) graft failures were identified after a pregnancy, with a median follow-up of 8.08 years. Although women with preeclampsia had higher median preconception serum creatinine concentration (1.24 [interquartile range, 1.00-1.50] versus 1.13 [0.99-1.36] mg/dl; P = 0.02), in all survival models, preeclampsia was not associated with higher death-censored graft failure. In multivariable analysis of maternal factors (age, body mass index, primary kidney disease and transplant-pregnancy interval, preconception serum creatinine concentration, era of birth event, and tacrolimus or cyclosporin exposure), only era and preconception serum creatinine concentration ≥1.24 mg/dl (odds ratio, 2.48; 95% confidence interval [CI], 1.19 to 5.18) were associated with higher preeclampsia risk. Both preconception eGFR <45 ml/min per 1.73 m 2 (adjusted hazard ratio [HR], 5.55; 95% CI, 3.27 to 9.44, P < 0.001) and preconception serum creatinine concentration ≥1.24 mg/dl (adjusted HR, 3.06; 95% CI, 1.77 to 5.27, P < 0.001) were associated with a higher risk of graft failure even after adjusting for maternal characteristics.

CONCLUSIONS

In this large and contemporaneous registry cohort, preeclampsia was not associated with worse graft survival or function. Preconception kidney function was the main determinant of graft survival.

Pregnancy after Kidney Transplantation-Impact of Functional Renal Reserve, Slope of eGFR before Pregnancy, and Intensity of Immunosuppression on Kidney Function and Maternal Health

Women of childbearing age show increased fertility after kidney transplantation. Of concern, preeclampsia, preterm delivery, and allograft dysfunction contribute to maternal and perinatal morbidity and mortality. We performed a retrospective single-center study, including 40 women with post-transplant pregnancies after single or combined pancreas-kidney transplantation between 2003 and 2019. Outcomes of kidney function up to 24 months after the end of pregnancy were compared with a matched-pair cohort of 40 transplanted patients without pregnancies. With a maternal survival rate of 100%, 39 out of 46 pregnancies ended up with a live-born baby. The eGFR slopes to the end of 24 months follow-up showed mean eGFR declines in both groups (-5.4 ± 14.3 mL/min in pregnant versus -7.6 ± 14.1 mL/min in controls). We identified 18 women with adverse pregnancy events, defined as preeclampsia with severe end-organ dysfunction. An impaired hyperfiltration during pregnancy was a significant risk contributor for both adverse pregnancy events (p < 0.05) and deterioration of kidney function (p < 0.01). In addition, a declining renal allograft function in the year before pregnancy was a negative predictor of worsening allograft function after 24 months of follow-up. No increased frequency of de novo donor-specific antibodies after delivery could be detected. Overall, pregnancies in women after kidney transplantation showed good allograft and maternal outcomes.

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.

Parenthood with kidney failure: Answering questions patients ask about pregnancy

Achieving parenthood can be an important priority for women and men with kidney failure. In recent decades, the paradigm has shifted toward greater support of parenthood, with advances in our understanding of risks related to pregnancy and improvements in obstetrical and perinatal care. This review, codesigned by people with personal experience of kidney disease, provides guidance for nephrologists on how to answer the questions most asked by patients when planning for parenthood. We focus on important issues that arise in preconception counseling for women receiving dialysis and postkidney transplant. We summarize recent studies reflecting pregnancy outcomes in the modern era of nephrology, obstetrical, and perinatal care in developed countries. We present visual aids to help clinicians and women navigate pregnancy planning and risk assessment. Key principles of pregnancy management are outlined. Finally, we explore outcomes of fatherhood in males with kidney failure.