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

Long-term maternal outcomes of pregnancy after orthotopic liver transplantation in the Netherlands: A retrospective multicenter cohort study

Pregnancy after orthotopic liver transplantation (OLT) puts the mother, child, and transplanted organ at risk. Little is known about long-term outcomes. We performed a nationwide retrospective cohort study to evaluate short-term and long-term outcomes of post-OLT pregnancies. The secondary aim was to assess predictors for adverse pregnancy outcomes. A composite outcome of preeclampsia, preterm birth, low birth weight, and neonatal intensive care unit admission was made. Survival of women who received a transplant at <50 years of age with and without pregnancy after OLT were compared (Dutch Organ Transplantation Registry data). Descriptive statistics, regression analysis, Kaplan-Meier and log-rank analysis, and generalized estimating equation analysis were used. Among the included 70 women with 113 pregnancies >20 weeks of gestation, hypertension occurred in 20% and preeclampsia in 12%. The live birth rate was 87%; 33% were preterm, and 23% had low birth weight. Long-term follow-up (median 10 y [IQR: = 4-14]) showed small changes in serum creatinine and bilirubin ( p < 0.001). Sixteen mothers (23%) died during follow-up (median 8 y [IQR: = 4-12]), with all their children aged <18 years. No difference in survival was found when comparing women with and without pregnancy after OLT. The composite outcome occurred in 43/98 of pregnancies. Higher body mass index (BMI) and maternal age at conception increased the composite outcome risk (OR: 1.24, p < 0.01, and OR: 1.25, p = 0.01, respectively). To conclude, pregnancy after OLT does not seem to influence long-term outcomes of graft, kidney function, or patient survival in most cases. However, although pregnancy does not seem to impact survival after OLT, we do show that a substantial number of children will lose their mothers early in life. We believe this is important for pregnancy couseling of patients with an OLT and their partners.

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.

Reassuring pregnancy outcomes in women with mild COL4A3-5-related disease (Alport syndrome) and genetic type of disease can aid personalized counseling

Individualized pre-pregnancy counseling and antenatal care for women with chronic kidney disease (CKD) require disease-specific data. Here, we investigated pregnancy outcomes and long-term kidney function in women with COL4A3-5 related disease (Alport Syndrome, (AS)) in a large multicenter cohort. The ALPART-network (mAternaL and fetal PregnAncy outcomes of women with AlpoRT syndrome), an international collaboration of 17 centers, retrospectively investigated COL4A3-5 related disease pregnancies after the 20th week. Outcomes were stratified per inheritance pattern (X-Linked AS (XLAS)), Autosomal Dominant AS (ADAS), or Autosomal Recessive AS (ARAS)). The influence of pregnancy on estimated glomerular filtration rate (eGFR)-slope was assessed in 192 pregnancies encompassing 116 women (121 with XLAS, 47 with ADAS, and 12 with ARAS). Median eGFR pre-pregnancy was over 90ml/min/1.73m2. Neonatal outcomes were favorable: 100% live births, median gestational age 39.0 weeks and mean birth weight 3135 grams. Gestational hypertension occurred during 23% of pregnancies (reference: 'general' CKD G1-G2 pregnancies incidence is 4-20%) and preeclampsia in 20%. The mean eGFR declined after pregnancy but remained within normal range (over 90ml/min/1.73m2). Pregnancy did not significantly affect eGFR-slope (pre-pregnancy β=-1.030, post-pregnancy β=-1.349). ARAS-pregnancies demonstrated less favorable outcomes (early preterm birth incidence 3/11 (27%)). ARAS was a significant independent predictor for lower birth weight and shorter duration of pregnancy, next to the classic predictors (pre-pregnancy kidney function, proteinuria, and chronic hypertension) though missing proteinuria values and the small ARAS-sample hindered analysis. This is the largest study to date on AS and pregnancy with reassuring results for mild AS, though inheritance patterns could be considered in counseling next to classic risk factors. Thus, our findings support personalized reproductive care and highlight the importance of investigating kidney disease-specific pregnancy outcomes.

Modelling changes in the pharmacokinetics of tacrolimus during pregnancy after kidney transplantation: A retrospective cohort study

AIMS

Pregnancy after kidney transplantation is realistic but immunosuppressants should be continued to prevent rejection. Tacrolimus is safe during pregnancy and is routinely dosed based on whole-blood predose concentrations. However, maintaining these concentrations is complicated as physiological changes during pregnancy affect tacrolimus pharmacokinetics. The aim of this study was to describe tacrolimus pharmacokinetics throughout pregnancy and explain the changes by investigating covariates in a population pharmacokinetic model.

METHODS

Data of pregnant women using a twice-daily tacrolimus formulation following kidney transplantation were retrospectively collected from 6 months before conception, throughout gestation and up to 6 months postpartum. Pharmacokinetic analysis was performed using nonlinear mixed effects modelling. Demographic, clinical and genetic parameters were evaluated as covariates. The final model was evaluated using goodness-of-fit plots, visual predictive checks and a bootstrap analysis.

RESULTS

A total of 260 whole-blood tacrolimus predose concentrations from 14 pregnant kidney transplant recipients were included. Clearance increased during pregnancy from 34.5 to 41.7 L/h, by 15, 19 and 21% in the first, second and third trimester, respectively, compared to prior to pregnancy. This indicates a required increase in the tacrolimus dose by the same percentage to maintain the prepregnancy concentration. Haematocrit and gestational age were negatively correlated with tacrolimus clearance (P ≤ 0.01), explaining 18% of interindividual and 85% of interoccasion variability in oral clearance.

CONCLUSIONS

Tacrolimus clearance increases during pregnancy, resulting in decreased exposure to tacrolimus, which is explained by gestational age and haematocrit. To maintain prepregnancy target whole-blood tacrolimus predose concentrations during pregnancy, increasing the dose is required.

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.

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.