A best-practice position statement on pregnancy after kidney transplantation: focusing on the unsolved questions. The Kidney and Pregnancy Study Group of the Italian Society of Nephrology

Abstract

Kidney transplantation (KT) is often considered to be the method best able to restore fertility in a woman with chronic kidney disease (CKD). However, pregnancies in KT are not devoid of risks (in particular prematurity, small for gestational age babies, and the hypertensive disorders of pregnancy). An ideal profile of the potential KT mother includes “normal” or “good” kidney function (usually defined as glomerular filtration rate, GFR ≥ 60 ml/min), scant or no proteinuria (usually defined as below 500 mg/dl), normal or well controlled blood pressure (one drug only and no sign of end-organ damage), no recent acute rejection, good compliance and low-dose immunosuppression, without the use of potentially teratogen drugs (mycophenolic acid and m-Tor inhibitors) and an interval of at least 1–2 years after transplantation. In this setting, there is little if any risk of worsening of the kidney function. Less is known about how to manage “non-ideal” situations, such as a pregnancy a short time after KT, or one in the context of hypertension or a failing kidney. The aim of this position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology is to review the literature and discuss what is known about the clinical management of CKD after KT, with particular attention to women who start a pregnancy in non-ideal conditions. While the experience in such cases is limited, the risks of worsening the renal function are probably higher in cases with markedly reduced kidney function, and in the presence of proteinuria. Well-controlled hypertension alone seems less relevant for outcomes, even if its effect is probably multiplicative if combined with low GFR and proteinuria. As in other settings of kidney disease, superimposed preeclampsia (PE) is differently defined and this impairs calculating its real incidence. No specific difference between non-teratogen immunosuppressive drugs has been shown, but calcineurin inhibitors have been associated with foetal growth restriction and low birth weight. The clinical choices in cases at high risk for malformations or kidney function impairment (pregnancies under mycophenolic acid or with severe kidney-function impairment) require merging clinical and ethical approaches in which, beside the mother and child dyad, the grafted kidney is a crucial “third element”.

Nutritional Challenges in Pregnant Women with Renal Diseases: Relevance to Fetal Outcomes

“…In general, it is recommended an energy supply of about 30 Kcal/kg/die with a protein intake of 1 g/kg/die. In case of reduced renal function, even in RT patients, it is conceivable that a protein-restricted diet, such as advised in CKD patients, should be suitable, even if there are no data [75]. For vitamins and micronutrients, the advice for the general population should be followed.…”

“…Of note, in case of pregnancy in renal transplanted patients, a multidisciplinary pre-pregnancy counseling is necessary to discuss the possible complications, to assess metabolic profile and avoid exposition to teratogenic drugs (for example mycophenolate mofetil) [75].…”

Pregnancy Following Kidney Transplantation

“…Bariyer yöntemleri etkinliği az olmasına rağmen cinsel yolla geçen hastalıkları da önlediği için en çok tercih edilen yöntemlerdir. (7,8).…”

“…İmmünosüpresyonun ayarlandığı tüm hastalarda allogreftin stabilitesini sağlamak için birkaç ay boyunca allogreft fonksiyonu yakından izlenmelidir. Hastalar bağışıklığın baskılanmasındaki değişikliklerden sonra rejeksiyon riskinin artabileceği konusunda bilgilendirilmelidir (7,8). Gebelerde BB ilaçların güvenirliliği Tablo 1'de özetlenmiştir.…”

Contraception in chronic kidney disease: a best practice position statement by the Kidney and Pregnancy Group of the Italian Society of Nephrology

“…With this in mind, the Italian Society of Nephrology's Project Group on Kidney and Pregnancy has undertaken the preparation of the present best practice statement. We will try to summarize the available evidence and provide answers to open questions on contraception in CKD integrating the currently available "best practice" statements on pregnancy in CKD, dialysis, kidney transplantation and follow-up after preeclampsia [24][25][26][27].…”