Pregnancy Outcomes in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis

Abstract

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.

Risk of Adverse Pregnancy Outcomes in Women with CKD

“…[13][14][15][16] Other diseases such as IgA or reflux nephropathy usually display a good prognosis, at least in the presence of normal kidney function. [17][18][19][20][21][22][23] Despite rising interest, few large cohorts of nonselected patients with CKD encompassing the most frequently encountered disorders in clinical practice are available.…”

Intrauterine growth restriction in pregnant women after kidney transplantation as a marker of preeclampsia

“…This complication is up to 8 times more common in that group of women than in the general population [5]. Due to the fact that the etiology of preeclampsia remains to be fully elucidated, every few years its classification changes, making it difficult to compare patients from the past, especially after 2014.…”

“…Preeclampsia is one of the most frequently reported complications in pregnancies after kidney transplantation [4,5]. This complication is up to 8 times more common in that group of women than in the general population [5].…”

Medical Management of the Kidney Transplant Recipient

“…Graft function is optimal, defined as a serum creatinine <1.5 mg/dL, (132 micromol/L) with <500 mg/24 h protein excretion b. There are no concurrent fetotoxic infections, such as CMV c. The patient is not on known teratogenic or fetotoxic medications d. The immunosuppressive regimen is stable at maintenance levels A recent meta-analysis covering 50 studies, 4706 pregnancies and 3570 kidney transplant patients, provides the proof as to why pregnancies in these patient population is deemed high-risk (71). According to that meta-analysis, complications of preeclampsia (27.0%), gestational diabetes (8.0%), Cesarean section (56.9%) and preterm delivery (45.6%) were higher than the general US population (3.8%, 3.9%, 31.9% and 12.5%, respectively).…”

“…The overall post-transplant live birth rate was 73.5% compared to 66.7% for general US population; similarly, the overall post-transplant miscarriage rate of 14.0% was lower than 17.1%. Transplant recipients usually deliver late preterm (34-36 weeks), roughly 30-50% pregnancies experience intra-uterine growth restriction to some degree and on average give birth to low birth weight babies (~2.5 grams) (70)(71)(72). Pregnancy doesn't increase the risk of rejection (71).…”