Pregnancy in the Renal Transplant Recipient

Usage of Tacrolimus and Mycophenolic Acid During Conception, Pregnancy, and Lactation, and Its Implications for Therapeutic Drug Monitoring: A Systematic Critical Review

BACKGROUND

Conception, pregnancy, and lactation following solid organ transplantation require appropriate management. The most frequently used immunosuppressive drug combination after solid organ transplantation consists of tacrolimus (Tac) plus mycophenolic acid (MPA). Here, the effects of Tac and MPA on fertility, pregnancy, and lactation are systematically reviewed, and their implications for therapeutic drug monitoring (TDM) are discussed.

METHODS

A systematic literature search was performed (August 19, 2019) using Ovid MEDLINE, EMBASE, the Cochrane Central Register of controlled trials, Google Scholar, and Web of Science, and 102 studies were included. Another 60 were included from the reference list of the published articles.

RESULTS

As MPA is teratogenic, women who are trying to conceive are strongly recommended to switch from MPA to azathioprine. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes. Nevertheless, in 2015, the drug label was updated with additional risk minimization measures in a pregnancy prevention program. Data on MPA pharmacokinetics during pregnancy and lactation are limited. Tac treatment during conception, pregnancy, and lactation seems to be safe in terms of the health of the mother, (unborn) child, and allograft. However, Tac may increase the risk of hypertension, preeclampsia, preterm birth, and low birth weight. Infants will ingest very small amounts of Tac via breast milk from mothers treated with Tac. However, no adverse outcomes have been reported in children exposed to Tac during lactation. During pregnancy, changes in Tac pharmacokinetics result in increased unbound to whole-blood Tac concentration ratio. To maintain Tac concentrations within the target range, increased Tac dose and intensified TDM may be required. However, it is unclear if dose adjustments during pregnancy are necessary, considering the higher concentration of (active) unbound Tac.

CONCLUSIONS

Tac treatment during conception, pregnancy and lactation seems to be relatively safe. Due to pharmacokinetic changes during pregnancy, a higher Tac dose might be indicated to maintain target concentrations. However, more evidence is needed to make recommendations on both Tac dose adjustments and alternative matrices than whole-blood for TDM of Tac during pregnancy. MPA treatment in men during conception seems to have no adverse effect on pregnancy outcomes, whereas MPA use in women during conception and pregnancy is strongly discouraged.

Contraception After Kidney Transplantation, From Myth to Reality: A Comprehensive Review of the Current Evidence

There is a misconception among transplant clinicians that contraception after a successful renal transplant is challenging. This is partly due to the complex nature of transplant patients, where immunosuppression and graft dysfunction create major concerns. In addition, good evidence regarding contraception and transplant is scarce, with most of the evidence extrapolated from observational and case-controlled studies, thus adding to the dilemma of treating these patients. In this review, we closely analyzed the different methods of contraception and critically evaluated the efficacy of the different options for contraception after kidney transplant. We conclude that contraception after renal transplant is successful with acceptable risk. A multidisciplinary team approach involving obstetricians and transplant clinicians to decide the appropriate timing for conception is recommended. Early counseling on contraception is important to reduce the risk of unplanned pregnancies, improve pregnancy outcomes, and reduce maternal complications in patients after kidney transplant. To ascertain appropriate advice on the method of contraception, individualizing the method of contraception according to a patient's individual risks and expectations is essential.

Pregnancy in a renal transplant recipient with HIV-1 infection: a case report

We report the first case of a pregnancy in a renal transplant recipient with HIV infection. She underwent renal transplantation in 2005 and became pregnant in 2009. The patient underwent vaginal delivery and a healthy full-term, female baby was born. Almost 6 years after delivery, both mother and child were doing well. The management of concurrent renal transplantation, HIV infection and pregnancy was extremely challenging. Women with HIV infection who have undergone renal transplantation should be accurately informed of the potential health risks for them and their offspring. Multidisciplinary teams are mandatory in order to properly manage these patients.

Peripartum anesthetic management of renal transplant patients--a multicenter cohort study

As the number and success of renal transplantation has grown, there has been an increase in the number of renal transplant patients giving birth. To date, there has been no data on obstetric anesthesia management of these patients. The purpose of this study was to build an Israeli national database on parturients after renal transplant. A sixteen-year (calendar years 1996-2011) retrospective study was conducted at three major tertiary centers with a combined current birth rate of approximately 25,000 deliveries annually. We found 83 labors in 64 women. Forty-two percent of this population suffered from hypertension while 12.5% had diabetes. Forty-seven percent of women had a vaginal delivery while 53% of women had a cesarean section. The rate of epidural analgesia for labor was 59%, and rate of regional anesthesia during cesarean section was 75%. There were no anesthetic complications in any cases. Standard ASA monitoring was used in all cases except for one woman with severe hypertension who required an arterial line during her cesarean section. Forty-seven percent of newborn were under 37 weeks with average gestational week 36 ± 3 days and birth weight 2.5 ± 0.7 kg. Average Apgar was 8.4 ± 1.3 at one minute and 9.3 ± 0.7 at five minutes. There was one neonatal death in the CS group due to placental abruption. Patients after renal transplant can safely undergo birth and obstetric analgesia.

Pregnancy management of diabetic renal transplant patients

Advances in medical care and options for medications for diabetic kidney transplant recipients have allowed for successful pregnancies to be carried to full term. End-stage renal disease leads to impaired fertility. Fertility is restored 1 to 6 months after a successful kidney transplant. Poor glycemic control near the conception period leads to a higher incidence of major fetal malformations and spontaneous abortion. Preconception counseling about risks of medications, control of comorbid conditions, stability of allograft function, and potential risks to mother, fetus, and allograft has to be done. Close and careful monitoring of mother, fetus, and allograft is important in ensuring a good outcome.

Pregnancy after renal transplantation: a review of registry and single-center practices and outcomes

Registries from North America, Australia and Europe are rich sources of clinical data on pregnancy after kidney transplantation. Single-center reports of pregnancy outcomes are limited by small sample sizes but not by the potential reporting bias that can impact registry data. Despite the differences in data pools, the obstetric and graft outcomes reported by single centers and registries have been similar. The majority of pregnancies are successful in renal transplant patients, but the risk of complications like pre-eclampsia, low birth weight and premature birth is high. Pregnancy has no significant impact on graft function or survival when baseline function is normal.