Complex chimerism: pregnancy after solid organ transplantation

Management of pregnancy in left ventricular assist device and heart transplant recipients: a concise review

PURPOSE OF REVIEW

Women of reproductive age are increasingly undergoing heart transplantation (HT) or left ventricular assist device (LVAD) implantation for advanced heart failure. This review is intended to give an overview of the current state of the art management of pregnancy in patients with LVAD or HT recipients.

RECENT FINDINGS

Heart transplant recipients are at increased risk for graft rejection, renal dysfunction, preeclampsia and worsening of comorbidities (hypertension and diabetes). Patients with LVAD are at higher risk of thromboembolic events, infections, right ventricular failure and require close surveillance during pregnancy. Preconception counseling must be offered to all women of reproductive age group with HT or LVAD to avoid unplanned pregnancies.

SUMMARY

A multidisciplinary approach with close antepartum and postpartum surveillance is recommended.

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.

Pregnancy outcomes in heart transplant recipients

BACKGROUND

The population of female heart transplant recipients of reproductive age is growing, and counseling regarding reproductive decisions is important. We describe maternal and fetal outcomes of pregnancy in the Transplant Pregnancy Registry International.

METHODS

Data regarding pregnancies between 1987 and 2016 were collected via questionnaires, phone interviews, and medical records review. Demographics, comorbidities, changes in immunosuppressive regimens, rejection episodes during pregnancy, data on maternal retransplants, and deaths were recorded.

RESULTS

A total of 91 patients reported 157 pregnancies. Mean maternal age at conception was 27 ± 5.6 years. The most common indications for transplant were congenital heart disease (22%) and viral myocarditis (18%). Average transplant to conception interval was 7 ± 6.1 years. Immunosuppression was calcineurin inhibitor-based in almost all patients, with 20% of recipients taking mycophenolic acid (MPA) while pregnant. Complications during pregnancy included pre-eclampsia (23%) and infections (14%). Rejection was reported during 9% of pregnancies and within 3 months postpartum in 7%. Livebirths occurred in 69%, with no neonatal deaths. Miscarriages occurred in 26% of pregnancies, 49% of which had MPA exposure. Mean follow-up post pregnancy was 8.9 ± 6.5 years. At last follow-up, 30 recipients had died, an average of 9.4 ± 6.2 years after pregnancy. The most common causes included allograft vasculopathy and rejection.

CONCLUSIONS

This is the largest reported series of pregnancies in heart transplant recipients and demonstrates that two thirds of pregnancies reported are successful. MPA exposure is associated with increased risk of teratogenicity and miscarriage. Pre-pregnancy counseling should include discussions of risk of MPA exposure, rejection, graft dysfunction, and maternal survival.

Pregnancy after lung and heart-lung transplantation: a French multicentre retrospective study of 39 pregnancies

Pregnancy after lung and heart–lung transplantation remains rare. This French study deals with change in lung function after a pregnancy and the maternal and newborn outcomes.

We retrospectively included 39 pregnancies in 35 women aged >20 years. Data on patients, course of pregnancies and newborns were collected from nine transplantation centres.

Mean age at time of pregnancy was 28 years. Cystic fibrosis affected 71% of patients. Mean±sd time between transplantation and pregnancy was 63±44 months. 26 births occurred (67%) with a mean term of 36 weeks of amenorrhoea and a mean birthweight of 2409 g. Prematurity was observed in 11 cases (43%). Forced expiratory volume in 1 s was 83.9% of predicted before pregnancy and 77.3% of predicted 1 year after the end of pregnancy (p=0.04). 10 patients developed chronic lung allograft dysfunction after delivery. Nine patients died at a mean±sd time after transplantation of 8.2±7 years and a mean±sd time after pregnancy of 4.6±6.5 years.

These data show that pregnancy remains feasible in lung and heart–lung transplant recipients, with more frequent maternal and newborn complications than in the general population. Survival in this cohort appears to be similar to the global survival observed in lung transplant recipients. Planned pregnancy and multidisciplinary follow-up are crucial.

Pregnancy in lung and heart–lung recipients remains rare but possible. There is a significant decrease in FEV₁ pre- and post-pregnancy, but overall outcomes are reassuring. Specialised, multidisciplinary follow-up is necessary.http://bit.ly/31iXxov

Management of reproductive health after cardiac transplantation

Pregnancy after cardiac transplantation poses immense challenges. Maternal risks include hypertensive disorders of pregnancy, rejection, and failure of the cardiac allograft that may lead to death. Fetal risks include potential teratogenic effects of immunosuppression and prematurity. Because of the high-risk nature of pregnancy in a heart transplant patient, management of reproductive health after cardiac transplantation should include preconception counseling to all women in the reproductive age group before and after cardiac transplantation. Reliable contraception is vital as nearly half of the pregnancies in this population are unintended. Despite the associated risks, successful pregnancies after cardiac transplantation have been reported. A multidisciplinary approach proposed in this review is essential for successful outcomes. A checklist for providers to guide management is provided.

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

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".

Pregnancy in the liver transplant recipient

During gestation, the woman's body undergoes various changes, and the line between physiology and pathology is very thin even in healthy women. Today, many of the liver transplant recipients are young women, who at one point in their lives may consider the possibility of pregnancy. Clinicians have to counsel them about the time of conception, the risk of miscarriage, the deterioration of the mother's health status, and the risk of birth defects. This review, based on our 20 years of clinical experience and up-to-date literature, provides comprehensive guidelines on pregnancy management in liver transplant recipients. Pregnancy in liver transplant recipients is possible but never physiological. Proper management and pharmacotherapy lowers the incidence of complications and birth defects. Critical factors for perinatal success include stable graft function before pregnancy, proper preparation for pregnancy, and cautious observation during its course. Liver Transplantation 22 1408-1417 2016 AASLD.

Bioethical considerations

The clinical literature notes that pregnancy has become an expected benefit of solid organ transplant. Establishing "best practices" in the management of this particular transplant population requires careful consideration of the ethical dimensions, broadly speaking, of posttransplant pregnancies and these women's lived experiences. In this article, we present the current clinical and social science posttransplant pregnancy research. We specifically address the psychosocial and ethical issues surrounding preconception counseling and posttransplant health quality of life and mothering and suggest areas for future research.

Pregnancy after heart and lung transplantation

Patients awaiting transplantation should be counseled regarding posttransplant contraception and the potential adverse outcomes associated with posttransplant conception. Pregnancy should be avoided for at least 1-2 years post transplant to minimize the risks to allograft function and fetal well-being. Transplant patients, particularly lung transplant recipients, have an increased risk of maternal and neonatal pregnancy-related complications, including prematurity and low birth weight, postpartum graft loss, and long-term morbidity and mortality compared to other solid-organ recipients. Therefore, careful monitoring by a specialized transplant team is crucial. Maintenance of immunosuppression is recommended, except for mycophenolate and mammalian target of rapamycin inhibitors (mTORi), which should be replaced before conception. Immunosuppressants must be regularly monitored and dosing adjusted to avoid graft rejection. Monitoring during labor is mandatory and epidural anesthesia recommended. Vaginal delivery should be standard and cesarean delivery only performed for obstetric reasons. Breastfeeding poses risks of neonatal exposure to immunosuppressants and is generally contraindicated.