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).

BACKGROUND: Kidney transplantation is the treatment of choice to restore fertility to women on renal replacement therapy. Over time, immunosuppressive, support therapies and approaches towards high-risk pregnancies have changed. The aim of this study was to analyse maternal-foetal outcomes in two cohorts of transplanted women who delivered a live-born baby in Italy in 1978-2013, dichotomized into delivery before and after January 2000. METHODS: A survey involving all the Italian transplant centres was carried out, gathering data on all pregnancies recorded since the start of activity at each centre; the estimated nationwide coverage was 75%. Data on cause of ESRD, dialysis, living/cadaveric transplantation, drug therapy, comorbidity, and the main maternal-foetal outcomes were recorded and reviewed. Data were compared with a low-risk cohort of pregnancies from two large Italian centres (2000-14; Torino and Cagliari Observational Study cohort). RESULTS: The database consists of 222 pregnancies with live-born babies after transplantation (83 before 2000 and 139 in 2000-13; 68 and 121 with baseline and birth data, respectively), and 1418 low-risk controls. The age of the patients significantly increased over time (1978-99: age 30.7 ± 3.7 versus 34.1 ± 3.7 in 2000-13; P < 0.001). Azathioprine, steroids and cyclosporine A were the main drugs employed in the first time period, while tacrolimus emerged in the second. The prevalence of early preterm babies increased from 13.4% in the first to 27.1% in the second period (P = 0.049), while late-preterm babies non-significantly decreased (38.8 versus 33.1%), thus leaving the prevalence of all preterm babies almost unchanged (52.2 and 60.2%; P = 0.372). Babies below the 5th percentile decreased over time (22.2 versus 9.6%; P = 0.036). In spite of high prematurity rates, no neonatal deaths occurred after 2000. The results in kidney transplant patients are significantly different from controls both considering all cases [preterm delivery: 57.3 versus 6.3%; early preterm: 22.2 versus 0.9%; small for gestational age (SGA): 14 versus 4.5%; P < 0.001] and considering only transplant patients with normal kidney function [preterm delivery: 35 versus 6.3%; early preterm: 10 versus 0.9%; SGA: 23.7 versus 4.5% (P < 0.001); risks increase across CKD stages]. Kidney function remained stable in most of the patients up to 6 months after delivery. Multiple regression analysis performed on the transplant cohort highlights a higher risk of preterm delivery in later CKD stages, an increase in preterm delivery and a decrease in SGA across periods. CONCLUSIONS: Pregnancy after transplantation has a higher risk of adverse outcomes compared with the general population. Over time, the incidence of SGA babies decreased while the incidence of 'early preterm' babies increased. Although acknowledging the differences in therapy (cyclosporine versus tacrolimus) and in maternal age (significantly increased), the decrease in SGA and the increase in prematurity may be explained by an obstetric policy favouring earlier delivery against the risk of foetal growth restriction.

Outcomes of Pregnancies After Kidney Transplantation: Lessons Learned From CKD. A Comparison of Transplanted, Nontransplanted Chronic Kidney Disease Patients and Low-Risk Pregnancies: A Multicenter Nationwide Analysis.

BACKGROUND: Kidney transplantation (KT) may restore fertility in chronic kidney disease (CKD). The reasons why maternofetal outcomes are still inferior to the overall population are only partially known. Comparison with the CKD population may offer some useful insights for management and counselling.Aim of this study was to analyse the outcomes of pregnancy after KT, compared with a large population of nontransplanted CKD patients and with low-risk control pregnancies, observed in Italy the new millennium. METHODS: We selected 121 live-born singletons after KT (Italian study group of kidney in pregnancy, national coverage about 75%), 610 live-born singletons in CKD, and 1418 low-risk controls recruited in 2 large Italian Units in the same period (2000-2014). The following outcomes were considered: maternal and fetal death; malformations; preterm delivery; small for gestational age (SGA) baby; need for the neonatal intensive care unit; doubling of serum creatinine or increase in CKD stage. Data were analyzed according to kidney diseases, renal function (staging according to CKD-epidemiology collaboration), hypertension, maternal age, parity, ethnicity. RESULTS: Maternofetal outcomes are less favourable in CKD and KT as compared with the low-risk population. CKD stage and hypertension are important determinants of results. Kidney transplantation patients with estimated glomerular filtration rate greater than 90 have worse outcomes compared with CKD stage 1 patients; the differences level off when only CKD patients affected by glomerulonephritis or systemic diseases ("progressive CKD") are compared with KT. In the multivariate analysis, risk for preterm and early-preterm delivery was linked to CKD stage (2-5 vs 1: relative risk 3.42 and 3.78) and hypertension (RR 3.68 and 3.16) while no difference was associated with being a KT or a CKD patient. CONCLUSIONS: The maternofetal outcomes in patients with kidney transplantation are comparable with those of nontransplanted CKD patients with similar levels of kidney function impairment and progressive and/or immunologic kidney disease.